Malaysian Sewerage Industry Guideline (Volume III) 1st Edition
Short Description
Malaysia Sewerage Industry Guideline - Volume 3: Sewer Networks and Pump Station...
Description
First Edition
Volume III Sewer Networks and Pump Stations Published by : Suruhanjaya Perkhidmatan Air Negara (SPAN)
Ministry of Energy, Water and Communication Malaysia
Foreword by the CEO of SPAN
M
unicipal wastewater treatment technology in Malaysia has evolved through several eras. In the past, only basic facilities were used, e.g. overhang latrines, pit privy, bucket systems and pour flush systems. Some improvement were observed when more modern system like septic tank and Imhoff tank systems were introduced into the country some 40 40 years ago. The municipal wastewater treatment in Malaysia sees a significant improvement in the last three decades since the introduction of new technologies in the form of oxidation ponds, aerated lagoons, activated sludge system, package systems and a variety of mechanical plants into into the country. However, sewage still remains as one of the major pollutants pollutants of our inland waterways. In the 1900s, the emergent of new treatment treatment technologies were mainly driven by the basic need to treat the sewage so as to control waterborne diseases. Today, the environmental regulations are becoming stringent with the increasing awareness toward sustainable environmental management. Allowable effluent discharge limits are becoming lower globally. Public are also more educated and more alert on the needs to preserve the environment. Hence the evolution of municipal wastewater treatment technologies now are even more revolutionary and more rapid in order to meet the stricter regulators’ requirements and to compete in the increasing competitive market. While the nation moves towards achieving the status of a developed country, sustainability of our environment, in particularly the Malaysian rivers and streams must be strengthened. With this vision in mind, the Sewerage Services Department published its first edition of the guidelines for sewerage industry titled “Design and Installation of Sewerage Systems” in January 1995. The main purpose of these guidelines is to assist the
developer and his designer to plan and design systems acceptable to the regulatory authorities which, in turn speeds up the approval processes. The Guidelines has clearly guided the nation sewerage industry towards achieving an improved sewerage system in the country. Subsequently, the Department further improvised the Guidelines in its second edition titled “Guidelines for Developers” which comprise five volumes covering specific topics. As a continuation to the efforts by the Sewerage Services Department, the National Water Services Commission undertake to revise and improvement the Guidelines for Developers. The product of the revision is “Malaysian Sewerage Industry Guidelines” which also comprise five volumes. These new revisions incorporated valuable knowledge gained by various stakeholders over a decade since the implementation of the first Guidelines for Developers and upkeep with the aim towards sustainable environmental management. Volume 1 Volume 2 Volume 3 Volume 4 Volume 5
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Sewerage Po Policy fo for Ne New De Developments Sewerage Works Procedures Sewer Networks and Pump ump Stati ations Sewage Tr Treatment Plants Septic Tanks
Volume 3 is specifically developed to provide a clear understanding of policies of the SPAN for the provision, refurbishment or upgrading of sewer networks and pumps stations. This volume covers planning, design, material selection, construction, installation and sewer testing requirements. The implementation of these guidelines since 90’s has undoubtedly achieved some levels of consistency in the design and construction of of sewerage network network nationwide. Finished sewerage sewerage networks quality has also been elevated while the operation and maintenance of the plants have improved significantly in terms of safety, health, health, operability and robustness. Whilst the adherence to these these guidelines is is necessary, engineering discretion is also required, especially for large sewers and pumping station with special situations. It is hoped that the publication of the third edition of this Volume Volume further improve the municipal wastewater treatment facilities facilities in this country. Dato’ Teo Yen Hua Chief Executive Officer SPAN
Copyright National Water Services Commission, Ministry of Energy, Water and Communications, 2008
All rights reserved.
This publication is protected by copyright.
No part of this publication may be reproduced, distributed, transmitted, stored in a retrieval system, or reduced to any electronic medium without the written authority of the Commissioner, National Water Services Commission, Ministry of Energy, Water and Communications,.
National Water Services Commission and Registered Certifying Agencies employees are permitted to copy and use the information in this publication, for internal purposes only.
Changes may be made periodically to the information herein.
TABLE OF CONTENTS Section 1
PAGE
Introduction
1.1
Purpose of This Volume
1
1.2
Who Should Use This Volume
1
1.3
Related Reference Material
1
Section 2 2.1
Planning, Material and Design Sewers
9
2.1.1
Pipe Material Selection Factors
9
2.1.2
Pipe Materials and Fittings
10
2.1.3
Pipe Selections
11
2.1.4
Requirements and Limitations for Use of Certain Pipe Material 11
2.1.5
Vitrified Clay Pipe
13
2.1.6
Reinforced Concrete Pipe
14
2.1.7
Ductile Iron Pipe
15
2.1.8
Steel Pipe
15
2.1.9
Solid Wall PE Pipe
16
2.1.10
Profiled Wall PE Pipe
16
2.1.11
Glass Reinforced Plastic Pipe
17
2.1.12
Acrylonitrile Butadiene Styrene Pipe
18
2.1.13
Sewer Design - General Requirements
18
2.1.14
Flow Rate Estimations
19
2.1.15
Sewer Cleansing Velocities
20
2.1.16
Pipe Roughness
20
2.1.17
Design of Gravity Sewer
21
2.1.18
Design of Force Mains
23
2.1.19
Vacuum Sewerage System
25
2.1.20
Computerised Sewer Designs
36
2.1.21
Design of Inverted Siphon
37
2.1.22
Structural Design of Sewers
37
2.2
2.3
2.4
Manhole
40
2.2.1
General
40
2.2.2
Manhole Location
42
2.2.3
Pipe Lengths from Manhole
42
2.2.4
Structural Design Considerations for Manhole
43
Manhole Covers and Frames
44
2.3.1
General
44
2.3.2
Load Class
44
2.3.3
Material
44
2.3.4
Dimensions, Marking and Surface Finish
44
2.3.5
Seating
44
2.3.6
Casting
45
2.3.7
Protective Coating
45
2.3.8
Water-tightness
45
2.3.9
Safety Features
45
2.3.10
Product Certification
45
Design of Network Pump Stations
46
2.4.1
Specifying of Network Pump Stations
46
2.4.2
General Requirements
46
2.4.3
Buffer Requirements
47
2.4.4
Pipework Requirements
47
2.4.5
Wet-well Requirements
48
2.4.6
Dry-well Requirements
48
2.4.7
Structural Requirements
49
2.4.8
Ventilation Requirements
49
2.4.9
Odour Control
50
2.4.10
Requirements for Lighting and Electrical Fittings
50
2.4.11
Acceptable Pump System (Fixed Speed Pumps Only) 50
2.4.12
Valve Requirements
51
2.4.13
Requirements for Level Controls
52
2.4.14
Requirements for Alarms
52
2.4.15
Requirements of Hydraulic Design and Performance52
2.4.16
Maintenance Considerations
52
2.4.17
Hazard and Operability
53
2.4.18
Other Requirements
53
2.5
2.6
Interceptors
56
2.5.1
Oil Interceptors
56
2.5.2
Grease Traps
56
Concrete and Reinforcement Requirements
56
2.6.1
Concrete
57
2.6.2
Cement
57
2.6.3
Steel Reinforcement and Falsework
57
Section 3
Construct ion and Installation
3.1
Introduction
59
3.2
Pipes and Fittings Delivery and Handling
59
3.2.1
Pipes and Fittings Delivery
59
3.2.2
Pipe Handling at Site
60
3.2.3
Pipe Storage
61
3.2.4
Pipe Damage
62
3.3
3.4
3.5
3.6
Trench Excavation
63
3.3.1
Protection of Affected Services, Structures, Pavements and Vegetation 63
3.3.2
Excavation Requirements
64
3.3.3
Bored Excavation
66
Pipe Laying
66
3.4.1
Pipe Bedding
66
3.4.2
Pipe and Fittings Placement
67
3.4.3
Pipe Jacking
68
3.4.4
Concrete Pipe Support
68
3.4.5
Pipe Cutting
69
3.4.6
Backfill of Trench
69
Pipe Jointing
70
3.5.1
Flexible Joints
70
3.5.2
Solvent Weld Joints
71
3.5.3
Flanged Joints
72
3.5.4
Steel Pipe Welded Joints (Field Welding)
72
3.5.5
Polyethylene Butt Welded Joints
73
Special Requirements For Sewer
73
3.6.1
Thrust Blocks for Pressure Pipelines
73
3.6.2
Pipe Restraints and Bulkheads on Steep Slopes
74
3.6.3
Pipe Embedment and Overlay
74
3.6.4
Sleeving of Ductile Iron Pipe
75
3.7
Reinstatement
75
3.8
Connections to Public Sewers
76
3.8.1
General
76
3.8.2
Junction Connections
77
3.8.3
Saddle Connections
77
3.8.4
Manhole Connections
78
Section 4
Sewer Testing 4.1
General
79
4.2
Testing of Gravity Sewers
80
4.3
Testing of Forced Mains
81
4.4
Testing of Manhole and other ancillaries
81
4.5
Low Pressure Air Test
82
4.5.1
General
82
4.5.2
Procedure for Testing
82
4.5.3
Procedures for Handling Air Test Failure
83
4.6
4.7
4.8
Low Pressure Water Test
84
4.6.1
General
84
4.6.2
Procedure
84
4.6.3
Handling Water Test Failures
85
High Pressure Water Test
86
4.7.1
General
86
4.7.2
Procedure
86
High Pressure Leakage Test
87
4.8.1
General
87
4.8.2
Procedure
87
4.9
Test for Straightness, Obstruction, and Grade
88
4.10
CCTV Inspection
88
4.10.1
Objectives of CCTV Inspection
89
4.10.2
Technical Requirements and References
89
4.10.3
Equipment Specifications and Test Devices
89
4.10.4. CCTV Inspection Requirements
4.11
4.12
90
4.10.5
CCTV Inspection Implementation Procedure for New Sewer Network 91
4.10.6
Interpretation Of Results From CCTV Inspection
93
4.10.7
Follow -Up Action to Be Taken
93
Infiltration Test
95
4.11.1
General
95
4.11.2
Procedure
95
4.11.3
Handling Test Failures
95
Water-tightness Test
95
4.12.1
General
95
4.12.2
Procedures
96
LIST OF TABLES Table 2.1a
Normal Pipe Roughness for Gravity Sewer
Table 2.1b
Normal Pipe Roughness for Force Mains for All Pipe Materials 21
Table 2.2
Typical Roughness Coefficient, ks
22
Table 2.3
Typical Manning Coefficient, n
22
Table 2.4
Typical Hazen-Williams Coefficient, C
23
Table 2.5
Condition/alarm of the station equipment
36
Table 2.6
Minimum Manhole Diameters
41
Table 2.7
Final inspection and testing
46
Table 2.8
Recommended Design Parameters for Pump Stations
54
Table 4.1
Test Duration
83
Table 4.2
Defect Grades Descriptions
94
Appendix A
21
Typical Drawings/ Diagrams
Figure A1
Standard Manhole Cover
98
Figure A2
Plan View of Typical Manhole
99
Figure A3
Typical Shallow Precast Concrete Manhole (Ground Level to Invert of Pipe 1.2m ≤ Depth 2,000.
iv.
The difference between stop and start levels shall be a maximum of 900 mm and a minimum of 450 mm.
v.
The difference in level between start or stop of duty and assist pumps shall be greater than or equal to 150 mm.
vi.
The minimum sump volume required shall accommodate the pumping cycle as per Table 2.4.
vii.
Benching shall be designed to minimise deposition of solid matter on the floor or walls of wet wells. The minimum slope of benching shall be 45o to the horizontal.
ix.
Benching shall preferably extend up to the pump intake. Self cleansing pumps shall be provided.
x.
Access into wet wells can be by vertical rung ladders with a maximum height of 6 m. When the height exceeds 6 m, intermediate platforms shall be provided with a change in direction of the ladder. Safety cages shall be provided for ladders exceeding 6 m.
xi.
Access covers shall have a minimum clear opening of 600 mm diameter and be sufficiently large to withdraw pumps vertically.
xii.
Access covers shall be capable of being lifted by, at most, two operators.
xiii.
On small pump stations (PE < 500), the practice is to provide difference between the cut-in and cut-out levels, the storage volume equal to 2 to 3 times the peak flow into the wet-well in litres per minute merely to protect the starting equipment from overheating and failure caused by too frequent starting and stopping.
xiv.
Emergency by-pass shall be provided either at any suitable manhole or wetwell. The discharge of the by-pass is preferred to the nearest watercourse and not to the perimeter drain of the pumping station. However, if this is not available then discharge to the nearest surface drain is allowed.
xv.
All wet-well shall be opened and come with stainless steel or other noncorrosive handrails. If stainless steel tubing is used, it shall be in-filled with concrete.
Dry-well Requirements i. ii.
48
Minimum hopper bottom slope shall be 1.5 vertical to 1.0 horizontal.
iii.
viii.
2.4.6
Suction channels shall be designed to avoid "dead zones", i.e., prevent solids and scum accumulation.
The size of dry well depends primarily on the number and type of pumps selected and on the piping arrangement. The requirement of pump installation is to provide at least 1.0m from each of the outboard pumps to the nearest side wall and at least 1.2m between each pump discharge casing.
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Planning, Material and Design
iii.
iv.
v.
2.4.7
Structural R equirements i.
Substructure shall be constructed of reinforced concrete with sulphate resistant cement to resist aggressive soils and groundwater.
ii.
Below ground walls shall be waterproofed and protected against aggressive soils and ground water.
iii.
Safe and suitable access to the wells shall be provided.
iv.
Internal walls shall be made resistant to sulphide corrosion by coating with high alumina cement or equivalent coatings.
v.
A penstock shall be installed upstream of the wet well to isolate the pump station.
vi.
For safety and operational reasons, a double penstock system may be required at specific plant.
vii.
The penstock spindle shall extend to pump station ground level and shall be suitably positioned to allow unrestricted operation of the penstock.
viii.
Access platforms shall be provided at all locations where dismantling work takes place.
ix.
2.4.8
Sufficient room is required between pumps to move the pump off its base with sufficient clearance left in between the suction and discharge piping for site repairs, inspection or removal from the pit to the surface for repairs. Consideration should be given to the installation of monorails, lifting eyes in the ceiling and A-frames for the attachment of portable hoist cranes and other devices. Provision should also be made for drainage of the dry well to the wet well.
Access covers shall be hinged with a lifting weight not exceeding 16 kg.
x.
Internal walls shall be made resistant to sulphide corrosion by coating with high alumina cement mortar lining, PVC lining or epoxy coating. Other materials used under special circumstances are subjected to approval from the relevant authority.
xi.
Penstock greater than 610mm x 610mm shall be motorised and come with manual overwrite switches. The actuator shall be located above ground level and above flood level for easy access in the event of flooding.
xii.
Protection against falling shall be provided by means of handrails at walkways and other working areas, where the fall equal or exceeds 1.5 m.
xiii.
Edge protection by means of kick plates of at least 50 mm in height shall be provided, where the drop is equal or exceeds 2.0 m.
xiv.
Proper drainage shall be provided at the collection bin area to ensure that liquid collected could be channelled back to the pump sump.
Ventilation Requirements i. ii. iii.
Ventilation shall be provided for all hazardous zones of the pump station. Covered pits shall have mechanical ventilation. Separate ventilation shall be provided for wet wells and dry wells.
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Planning, Material and Design
iv. v. vi.
2.4.9
2.4.10
Permanent ventilation rate and air changes shall comply with MS 1228. uPVC pipe is not permitted to be used as ventilation ducting between wetwell and dry-well.
Odour Control i.
the potential for odour generation, its impact and treatment, shall be considered in all aspects of design
ii.
isolate odorous gasses from general ventilation exhausts by containing identified odour generating sources with a separate local exhaust system
iii.
containment of the odour sources shall be by installing lightweight and corrosion resistant covers/enclosures designed for practical operation and maintenance works
iv.
the local exhaust odorous air shall be conveyed through well designed and balanced ductworks by a centrifugal fan to an effective odour treatment equipment
Requirements for Lighting and Electrical Fittings i.
Wet wells and dry wells shall be adequately lit.
ii.
Electrical installations shall be water proof, vapour proof and explosion proof.
iii.
If lights are fitted outside the well, then a spotlight system may be used to provide adequate illumination.
iv.
If portable lighting is used, proper ancillaries shall be made available.
v.
2.4.11
Lighting systems shall be interconnected with ventilation.
Equipments shall be sited above the highest water level.
Acceptable Pump System (Fixed Speed Pumps Only) The acceptable pump types are: i. ii. iii.
Centrifugal Screw Screw Centrifugal
Pumps are to be equipped with an auto restart mechanism to allow for automatic pump restart after power supply has resumed from a power failure. Pumps shall be equipped with protection accessory, e.g. thermal sensor, leakage sensor, etc. Dry well mounted pumps shall be equipped with auxiliary services such as cooling and gland seal water supply. Guide rail, lifting device and other wet well fittings must be fabricated of stainless steel, that is corrosion resistant. The use of hot dip galvanised iron is not recommended.
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Planning, Material and Design
Pre-fabricated pump stations are acceptable for small installations of PE less than or equal to 2,000.
2.4.12
Valve Requirements
2.4.12.1
General
2.4.12.2
2.4.12.3
i.
All valves shall be anti-clockwise opening.
ii.
All valves shall be suitable for use with wastewater and shall be designed to prevent retention of solids.
iii.
All valves shall be identified by durable name plate. Direction of flow shall be stamped on the valve body.
iv.
Bodies and cover for all valves shall be made of ductile iron to BS EN 1563: 1997. Special protective surfaces finishing by short blasting and finished externally with epoxy corrosion resistant coating shall be provided.
Gate Valve i.
Gate valves shall be of the non-rising screw wedge-gate type, double-faced ductile iron made and with resilient seated.
ii.
Gate valve shall conform to MS 1049, BS 5163 EN 1074 Part 2 or BS EN 1171: 2002.
iii.
The wedge of the gate valves shall be coupled and integral to the wedge hut in dezincification resistant high tensile brass (CZ 132) conforming to BS EN 2287 2: 1993, ISO 2872: 1985.
iv.
The spindle of the gate valve shall be of the inside screw non-rising with machined square or acme threads and operated by a handed or tee-key.
v.
Resilient seat valves shall have EPDM covered gates with inside screw non-rising stem. Stem shall be stainless steel conform to BS EN 10088-3: 2005.
Check Valve i.
Check valve shall be of approved by the Commission and suitable for their intended used and shall comply to BS 12334: 2001.
ii.
Check valves of non-slam swing type with extended spindle if necessary shall be provided at the upstream of a flow detection device.
iii.
Only single disc type of check valve shall be used.
iv.
The uses of internal counter weights are not permitted for check valve.
v.
Type non-slam check valve shall be of the full body type, with a domed access cover and only on moving pant, the flexible disc.
vi.
Disc of check valve shall be of precision molded NBR to BS EN 681-2: 2000. the disc shall be of one-piece construction, precision molded with an integral o-ring type sealing surface, and contain alloy steel and nylon reinforcement in the flexible use area.
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Planning, Material and Design
2.4.13
vii.
In the absence of check valve, the reverse rotation of the pump shall not exceed 150% of the rated speed or limit set by the manufacturer.
viii.
Tapping (12 mm BSP) shall be located upstream and downstream of check valves.
Requirements for Level Controls i.
ii.
Non-mercury type floats are recommended.
iv.
Hollow tube electrodes are not acceptable.
vi.
Level controls shall be placed where they are not affected by the turbulence of incoming flow and where they can be safely removed. When floats are used, cable hanger shall be installed.
Requirements for Alarms i.
ii.
iii.
2.4.15
Ultrasonic level control is recommended due to its clog-free nature.
iii.
v.
2.4.14
Either floats, electrodes or ultrasonic level controls may be used for startstop level of pumps. Those level controls with environmental friendly features are recommended.
Provision of alarms shall be considered inclusive of flammable gas, fire, high water level, bearing temperature, motor temperature, pump failure, power failure and vandalism. An alarm system should have an emergency power source capable operating for at least 24 hours in the event of failure of the main power supply and shall be telemetered thereto. Where no such facility exists, an audio-visual device shall be installed at the station for external observation.
Requirements of Hydraulic Design and Performance The followings items shall be provided: i. ii.
2.4.16
Pump curves
iii.
Operating point of pumps with respect to flow and total dynamic head (TDH)
iv.
Operating characteristics such as efficiency, horsepower, motor rating and NPSH
Maintenance Considerations i. ii. iii.
52
System curves
Mechanical and electrical equipment selected shall be robust and reliable and shall require minimal maintenance. Consideration should also be given to the availability of spare parts. The provision of appropriate lifting hoists and beams, and lifting eyes or similar features on heavy equipment, shall be considered.
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Planning, Material and Design
iv.
2.4.17
Hazard and Operability i. ii. iii.
2.4.18
Complete sets of current general arrangement and sectional drawings, operational, maintenance and service manuals, circuit diagrams and parts lists shall be supplied and be available at all times.
All pumping station design shall give consideration to all potential hazard and operability of design. HAZOP study may need to be conducted for pumping station design to identify the hazards and operability issues. The need for HAZOP study shall comply with requirements stipulated the Volume II.
Other Requirements Also refer to MS1228 for additional requirements.
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Planning, Material and Design
Table 2.8
Recommended Design Parameters for Pump Stations (continue on next page) Design Parameters
Description
Unit
Type of station Number of (all identical and sequentially)
pumps work
Pumps design flow
≤1,000
1,000 < PE ≤ 5,000
Wet well
Wet well
2 1 duty, 1 stand-by (100 % standby)
2 1 duty, 1 stand-by (100 % standby)
each at Q peak
each at Q peak
Maximum retention time at Q ave
min
30
30
Min pass through openings
mm
75
75
Minimum suction and discharge openings
mm
100
100
Pumping cycle (average flow conditions)
start/ hour
6 min 15 max
6 min 15 max
Lifting device* *-
-
54
PE
lifting davit
lifting beam and block
Weight < 16 kg: Manual lifting 16 kg ≤ Weight ≤ 250 kg: A davit or ‘A’ frame shall be arranged to allow items lifted by using manual chain hoist to be projected on a 1.2 m truck tray and positioned at 2m above road level. In the pump station, motorized hoist is required for lifting weight exceeding 100kg. Weight > 250 kg: A gantry with motorised hoist shall be arranged to allow items to be projected on a 1.2m truck tray and positioned at 2m above road level truck tray.
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Planning, Material and Design
Table 2.8
Recommended Design Parameters for Pump Stations Design Parameters
Description
Unit
Type of station
Number of (all identical and sequentially)
pumps work
Pumps design flow
5,000 < PE ≤ 20,000
PE > 20,000
wet well or dry well up to 10,000 PE 10,000 PE above – wet well and dry well
wet well and dry well
4 (2 sets) 1 duty, 1 assist, per set (100 % standby)
6 (3 sets) 1 duty, 1 assist, per set (50 % standby)
each at 0.5 Q peak
each at 0.25 Q peak
Maximum retention time at Q ave
min
30
30
Min pass through openings
mm
75
75
Minimum suction and discharge openings
mm
100
100
Pumping (average flow conditions)
start/ hour
6 min 15 max
6 - 15
Mechanical and block
mechanical
Lifting device* *-
-
cycle
Weight < 16 kg: Manual lifting 16 kg ≤ Weight ≤ 250 kg: A davit or ‘A’ frame shall be arranged to allow items lifted by using manual chain hoist to be projected on a 1.2 m truck tray and positioned at 2m above road level. In the pump station, motorized hoist is required for lifting weight exceeding 100kg. Weight > 250 kg: A gantry with motorised hoist shall be arranged to allow items to be projected on a 1.2m truck tray and positioned at 2m above road level truck tray.
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Planning, Material and Design
2.5
Interceptors All development schemes including individual premises that involve any sewerage works are vetted by the Director General. As part of this vetting, a check is made on the means of protecting public sewers from the discharge of prohibited matters such as oil, grease, petrochemicals, fats and solid food wastes. These matters can lead to congealment, constriction and blockage of sewers and pipelines and can also present hazards for sewer operations and maintenance. Therefore, suitable interceptors must be provided on the sewerage systems of garage workshops, engineering workshops, canteens or any premises that collect such matters. The design specfication may be acquired from the Director General for such a system.
2.5.1
Oil Interceptors Oil interceptors shall be provided in drain lines from areas such as garages, parking zones, service stations, machine shops and industrial plants where oil sediments and other volatile liquids are generated. Oil interceptors shall be designed in such a way that pollutants that are lighter than water liquid are trapped in a chamber and are prevented from being discharged to the public sewer. The chamber shall be normally fitted with a device to trap sediments and heavy particles that settle to the bottom. The removal of these sediments is required periodically. Intercepted oils shall be capable of being drained off for storage from suitable draw off points on a continuous operational basis. The interceptor shall be sized to accommodate the volumes of liquid likely to be discharged into the drainage system and the trapped pollutants.
2.5.2
Grease Traps Grease traps shall be provided in drain lines from areas such as restaurants, canteens, food processing and animal product or feeds factories, where grease and fat are likely to present in wash down waters or sullage. Grease traps shall be designed in such a way that solidified grease and fats are trapped in a chamber prior to discharge and may be skimmed off by means of a perforated strainer or bucket. The trap shall be sized adequately to contain the volume of liquid to be discharged from the drain line and the accumulated grease.
2.6
Concrete and Reinforcement Requirements Unless otherwise specified in other sections of this guidelines, all the concrete and reinforcement designed for pump stations and sewer networks shall comply with the following subsections.
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Planning, Material and Design
2.6.1
Concrete i.
Structural use of concrete shall be designed in accordance with MS 1195
ii.
Concrete shall generally comply with the relevant requirements in MS 523
iii.
Concrete for purposes other than manholes and pumping stations shall have a strength grade not less than Grade C20 where unreinforced, and not less than Grade C30 where reinforced
iv.
Structures that are designed for retaining sewage or other aqueous liquids shall be in accordance with BS8007, which specifies C35A concrete. Where required, higher strength grades may be specified by the Director General.
v.
Concrete exposed to a sewage atmosphere shall be lined with minimum 20 mm high alumina cement mortar complying with BS 915 Part 2 or 2 mm epoxy coating using a method of application approved by the Commission.
vi.
Concrete and cement mortar shall be made using a cement with sufficient resistance to sulphate attack if contacted with sewage
vii.
Approval for admixtures shall be obtained prior to inclusion in the concrete mix. All admixtures shall comply with MS 922
Aggregates shall comply with MS 29 and shall be coarse aggregate of maximum 20 mm nominal size
2.6.2
Cement One of the following cement shall be used to resist sulphate attack:
2.6.3
♦
Sulphate-resisting Portland cement complying with MS 1037
♦
Portland pulverised fuel ash cement complying with MS 1227
♦
Portland blastfurnace cement complying with MS 1389
♦
High silica content Portland cement complying with AS/NZS 3582
♦
Super-sulphated cement complying with BS 4248
Steel Reinforcement and Falsework
♦
Steel reinforcement shall comply with: 1.
MS 144 for cold reduced mild steel wire
2.
MS 145 for steel fabric
3.
MS 146 for hot rolled steel bars
♦
Scheduling, dimensioning, bending and cutting of steel reinforcement shall be in accordance with BS 8666
♦
Welding of steel reinforcement shall be in accordance with BS 7123
♦
Falsework shall be in accordance with BS 5975
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Malaysian Sewerage Industry Guidelines
Section 3 Construction and Installation
Construction and Installation
3.1
Introduction The correct installation of sewer systems is critical to the efficient and effective sewer system operation. Poor construction practice causes defects in the sewer at joints, along pipe barrels, at manholes, transition points (e.g. pipe to manhole), etc. Adequate site supervision and certification by consultants, with reference to approved design drawings, are therefore also required. The various construction and installation aspects of sewer system can be divided into: i.
Pipes and Fittings Delivery and Handling
ii.
Trench Excavation
iii.
Pipe Laying
iv.
Pipe Jointing
v.
Special Requirements for Ancillaries and Protection
vi.
Connections to Public Sewers
A description of the requirements for each stage is given below.
3.2
Pip es an d Fi tt in gs Deli ver y an d Hand lin g
3.2.1
Pipes and Fit tings Delivery a)
Materials delivered shall be from approved suppliers.
b)
Pipes and fittings on the delivery truck shall be secured firmly without damaging the pipe and fittings. Pipes and fittings shall be protected from any damage from the chain securings by using rubber, carpet or textile paddings.
c)
Pipes and fittings shall be checked to ensure that they have not moved during transportation.
d)
The pipes and fittings shall not be stacked in contact with each other and shall be separated by wooden spacers. The pipes stack can be secured by strapping or crating or can be secured by chocks at the outer pipes of each layer.
e)
Sockets of pipe in adjacent layers should be placed at opposite ends. Alternatively, sockets of adjacent pipe can be placed at opposite ends.
f)
Thermoplastic pipes (PE, ABS) shall not be supported in such a way that will cause the pipes to be twisted or bowed.
g)
Sewer pipe and components shall be checked for damage before being removed from the delivery truck
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3.2.2
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h)
The delivered pipes and fittings shall be checked against the design drawings and the delivery docket to ensure the pipe and fittings delivered are of the strength, stiffness, pressure class, length, joint type, diameter, fitting type, etc. specified.
i)
The delivery truck shall be positioned on a flat ground or in such a way that pipes and fittings would not fall off the truck when unsecuring the fastenings.
j)
Pipes and fittings shall not be pushed off the delivery truck and shall not be allowed to drop to the ground.
k)
When pipes are delivered in crates, the crates shall be removed intact, wherever possible.
l)
Pipes and fittings shall be lifted from the delivery truck using approved slings. Plastic covered wire mesh slings, hemp rope slings and chain slings without rubber sleeving are not suitable. For plastic pipes or pipes with external coating, webbed synthetic slings shall be used.
m)
Alternatively, pipes and fittings can be removed from the delivery truck by rolling a pipe at a time down the wooden runners. The pipe rolling shall be simultaneously controlled by ropes.
n)
Uncrated light thermoplastic pipes shall be lifted manually and carefully off the truck and shall not be dragged across the truck bed, edges or other hard and sharp surfaces. This is to avoid the scoring of plastic pipe.
Pipe Handling at Site a)
Pipes shall not be dragged or pushed over the ground.
b)
Pipes and fittings shall not be dropped in any way.
c)
Pipes and fittings shall not knock against each other or any other objects.
d)
The pipe lifting shall be controlled, where necessary, using ropes or by hand to ensure they do not knock against other objects.
e)
When rolled, pipes shall be rolled on smooth timber bearers, which are free of nails, fasteners, etc., and sufficiently raised above the ground to prevent hitting any rocky ground, tree roots, etc.
f)
When rolled on timbers, pipes shall not be pushed with a machinery bucket.
g)
Pipes with external coatings shall not be rolled. Instead, these pipe shall be lifted into place.
h)
Pipes and fittings shall be lifted using approved slings
i)
Pipe lifting equipment shall be of sufficient strength and reach to lift the intended individual pipe or crate of pipes.
j)
Mechanical lifting units (cranes, backhoes etc.) shall be stable or properly stabilised prior to lifting operations to ensure they would not tip and damage pipe and fittings.
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3.2.3
k)
The slings or chains used for lifting the load shall be secured to the load in the right manner to ensure the load does not slip or tilt excessively.
l)
All other safe lifting procedures not covered above shall be adopted.
m)
The lifting and moving of all the steel pipes and any pipes that contain internal linings shall follow the manufacturer instructions.
Pipe Storage a)
The pipe and fittings storage area shall be away from traffic and shall not obstruct any property access or pedestrian route.
b)
The pipe and fittings storage area shall be at a location that allows lifting machinery to position easily and safely for lifting pipes and fittings.
c)
Pipes shall be stacked on a flat and level firm ground or the base of the pipe stack shall be made level using additional solid timbers under base bearers.
d)
There shall be no rocks, tree roots, etc. under the pipe stack, which may cause point load.
e)
The sockets shall be alternated to different ends for each pipe stack layer. The sockets shall be protruded out of the stack.
f)
The base timber bearers shall be sound and without protrusions. The cross section of each timber shall be at least 75 mm by 75 mm. The base bearers shall provide support near the pipe ends, but placed behind sockets. The placement of base bears shall not be more than 1.5 m apart.
g)
VC, RC, DI, Steel and GRP pipe layers shall be separated using timber spacers of at least 50 mm wide and 50 mm thick. These spacers shall not be placed more than 1.5 m apart. These spacers will prevent pipes in each layer from touching pipes in the next layer.
h)
For VC and RC pipes that are not crated, the pipes shall not be stacked more than 3 pipes high. The pipe stacks shall be wedged to prevent them from rolling off the stack.
i)
Thermoplastic pipes (PE and ABS) shall be stacked in such a way to prevent them from being twisted or bowed.
j)
Thermoplastic pipes shall be either stacked in a pyramid with no more than 1 m high or in a square with vertical side supports for more than 2 pipes high.
k)
Plastic pipe and fittings shall be kept under a cover that prevents direct exposure to sun light.
l)
Plastic pipe and fittings shall not be covered with plastic sheeting.
m)
Plastic pipe and fittings shall be stored away from oils, greases, solvents and other aggressive chemicals.
n)
Plastic pipe shall be stored away from sources of heat such as engine exhausts.
o)
Care shall be taken to prevent scoring and scratching of plastic pipe and fittings.
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p)
Joint lubricants, rubber rings and other jointing materials shall be stored in a secured area that cannot be accessed by the public.
q)
Any safe pipe stacking procedure not covered above, but recommended by the manufacturer, shall be adopted.
r)
The rubber rings that are not delivered fitted to the pipe socket or sleeve shall be stored away from direct sunlight or continual artificial light. Also, the rubber rings shall be stored in a cool area that is away from oils, greases or other petroleum products.
s)
When rubber rings are delivered fitted to a pipe socket or sleeve, the pipe ends with the rubber ring shall be shielded from sunlight using a hessian cloth.
t)
Rubber rings shall be retained in the original sealed packaging until they are required.
Pipe Damage a)
Pipes, fittings (including coatings and linings) and rubber rings shall be inspected for damage on delivery, immediately before laying and after laying.
b)
Damaged pipe and fittings shall be identified and marked with an indelible marking of “Damaged” in a clearly distinguishable colour.
c)
Damaged rubber rings shall be cut through completely to prevent inadvertent use.
d)
Damaged pipe, fittings, and rubber rings shall be set aside and separated from the undamaged components.
e)
Pipes or fittings shall only be repaired if they can be restored back to a satisfactory state. Approval for repair shall be sought from the Commission before the repair.
f)
Pipes or fittings that are damaged and are in a repairable state shall be repaired according to the manufacturers instructions.
g)
Damaged pipe and fittings that are not permitted to be repaired shall be removed from the site as soon as possible.
h)
PE and ABS pipes with damage in the barrel, shall have the damaged section and at least 100 mm either side of the damage cut from the barrel.
i)
Repaired pipes and fittings shall be used only after the approval for reuse from the Commission is granted.
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3.3
Trench Excavation
3.3.1
Protection of Affected Services, Structures, Pavements and Vegetation a)
Owners of affected property, structures, services and other pipelines (sewer, water, gas, electricity, telecommunications lines, fuel lines, chemical pipelines) along or within 3 m of the excavation shall be notified.
b)
Services and other pipelines shall be protected, uncovered, temporarily supported or temporarily relocated in accordance with the conditions specified by the owner.
c)
Where the shutdown of a service or pipeline cannot be avoided, arrangements shall be made with the owner of the service or the pipeline on the closure and reinstatement requirements.
d)
Damages to any affected structure, service or pipeline shall be avoided.
e)
Damage to any structure, service or pipeline shall be informed to the owner and shall be repaired as quickly as possible in accordance with the requirements of the owner.
f)
Damage to vegetation (trees, bushes, gardens), paved areas (roads, footways, kerbs), fences or other property within the construction zone shall be minimised.
g)
The length of time that any paved route is out of use shall be minimised.
h)
Not more than half the width of a roadway shall be disrupted at any one time.
i)
Spoils shall not be placed on road surfaces. Where there is no other approved storage area, spoil shall be carted away.
j)
Non-reusable material excavated from roadways shall be disposed of in an appropriate manner. Only fillings approved by the responsible authority for the roads shall be used as refill.
k)
Excavations shall be sufficiently clear of building foundations.
l)
Excavations adjacent to roads shall be at least 1 m clear of the road edge except when otherwise approved by the Director General.
m)
Trenches adjacent to roads, buildings and structures shall be continuously supported until the trench is refilled.
n)
Structures, services, vegetation, paving, or other property not within the construction zone shall not be damaged.
o)
Temporary fencing shall be provided where barriers such as fences and walls are dismantled.
p)
Warning signs and temporary fencing shall be provided at the work site for excavation spoils, access routes, steep or loose slopes resulted by excavation work.
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q)
3.3.2
Warning signs shall be in accordance with the relevant Malaysian Standards. Some of the relevant Malaysian Standards are:
i.
MS 980 Specification for safety signs and colours: colorimetric and photometric properties of materials
ii.
MS 981 Specification for safety signs and colour: colour and design
iii.
MS 982 Specification for safety signs, notices and graphic symbols
r)
Adequate lighting and reflective signals, which can make clearly visible the perimeter of the work site to pedestrians and traffic, shall be provided.
s)
Adequate lighting shall be provided for works undertaken in poor lighting or at night. Lighting in confined spaces shall be explosion proof.
t)
Alternative means of access shall be provided to rights of way, buildings and property where usual means of access are disrupted by the excavation.
u)
Soils shall not be taken out of the work site, put onto pavements or flushed down to drains or water courses.
v)
Road drains, gutters and channels shall not be obstructed.
w)
Drains disturbed by works shall be rerouted to ensure continual operation.
x)
Sufficient top soil that will be used for surface reinstatement shall be removed and stockpiled separately.
y)
When dewatering, care shall be taken to ensure that the adjacent structures, services and building foundations are not affected.
z)
Water removed from the excavation shall be disposed of without damaging other property or causing a public nuisance.
Excavat ion Requir ements a)
The required line of the sewer and manhole locations shall be set out using accepted surveying practices.
b)
Manhole locations shall be pegged and the line of the excavation between manholes shall be maintained straight using one or more of pegs, chalk lines laser beam lines and string line.
c)
Changes to the line, grade or level due to unforeseen obstructions or proximity to services shall be approved by the Commission prior to making the actual changes.
d)
The trench shall be excavated precisely along the marked alignment to ensure the sewer will be in the centre of the trench.
e)
The trench shall be excavated to a depth so that the sewer can achieve the specified level and grade when the specified bedding depth is used.
f)
Over-excavation of the trench depth shall be avoided.
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g)
For open excavation, depending on depth of sewer and soil condition, sufficient slope protection must be provided and supported by approved consultant drawings and design.
h)
When the excavations are required to cross rivers, railway lines, and any other obstructions, minimum soil cover requirements specified by the responsible authorities shall be observed. In extreme cases, inverted siphons may be necessary. Minimum requirements for inverted siphons are shown in the standard drawings in the Appendix, and they must be designed individually based on actual locations.
i)
When working with poor ground conditions, construction depth shall be minimised. Reference shall be made to the approved longitudinal and crosssectional sewer profile drawings, which give details of construction based on soil reports.
j)
The base of the trench shall be trimmed carefully to level and grade.
k)
Where sight rails are used to determine trench excavation depth, at least three sight rails shall be used for each manhole length.
l)
Sight rails shall be fixed to a uniform height above sewer invert.
m)
Rocks that cause an uneven trench base shall be removed. The resulting holes shall be refilled with the specified embedment material.
n)
The trench in the pipe zone shall be excavated to the minimum width limits as given in the specification, except where a wider trench is needed due to unsupportive soil adjacent to the pipe zone.
o)
The trench sides shall be vertical except where permitted otherwise by the Commission.
p)
To prevent trench wall from collapsing which may lead to injuries and pipe damage, timber or steel support shall be provided in the trench when the trench is deeper than 1.5 m. These supports must be adequately designed for.
q)
Where possible, spoil shall be placed only on one side of the trench.
r)
Spoil shall be placed at an appropriate distance away from the edge of the trench (minimum 600 mm). This is to prevent the spoil material from falling into the trench or to prevent the weight of the spoil from collapsing the trench wall.
s)
Unsupportive (very soft, loose, spongy or puddly) soil in the base of the trench (as determined by the Commission) shall be removed and replaced. The replacement based shall be sufficiently supportive and shall require approval from the Commission.
t)
Excessive excavation shall be refilled with approved materials to the specified compaction.
u)
Where possible, the excavated trench shall be kept free of water until sufficient backfill is placed above the sewer. This is to prevent the base of the trench from becoming spongy and to prevent the pipe from moving off line or grade.
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3.3.3
v)
Changes to the line, grade or level of the sewer shall be properly recorded for incorporation in the as-constructed drawings. All as-constructed drawings, irrespective of whether there are changes to the original design drawings, shall be certified by consultants and shall include sufficient details, including as-built sewer invert levels. These drawings shall be submitted to the Director General.
w)
Excavation shall not proceed too far ahead of pipe laying to avoid damages from flooding or spoil.
x)
Excavation shall not proceed too far ahead of the required trench support placing to avoid trench wall from collapsing.
y)
Excavation shall comply with the relevant Occupational Safety and Health Act (OSHA) requirements for safety.
Bored Excavation a)
The bore shall be on the line, level and grade and of sufficient diameter to allow pipes to be inserted without over-stressing the joints or damaging the pipes.
3.4
Pipe Laying
3.4.1
Pipe Bedding
66
a)
Only approved materials are allowed to be used for pipe embedment. They shall be in accordance to the approved longitudinal and cross-sectional sewer profile drawings, which shall also provide details of the designed bedding types.
b)
The bedding material shall be placed as soon as possible after the base of the trench is prepared and excess water has been removed.
c)
Granular bedding shall be placed, compacted and graded so that it offers continuous support to the sewer. The compacting, where required, shall achieve a uniform density.
d)
A small hole shall be left in granular bedding for each socket, jointing sleeve, flange, etc. that may project into the bedding. The holes shall be of size that is just sufficient for projections to be clear of bedding. Long and large holes that may undermine the pipe barrel support are not allowed.
e)
A recess shall be made in the bedding to permit the withdrawal of the sling without disturbing the remaining bedding.
f)
Where the bedding is disturbed, the pipe shall be raised again to repair the bedding.
g)
Pegs or other temporary aids to levelling shall be removed before pipe laying.
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3.4.2
Pipe and Fi tti ngs Pl acement a)
Before lowering the pipes into the trench, pipes shall be placed next to the trench away from the trench edge. The pipes shall be placed on the opposite side of the spoil beside the trench with their sockets facing upstream. Where required, the pipes shall be blocked or chocked to prevent any rolling.
b)
Pipes and fittings (including linings, sheathings and protective paintworks) shall be checked for damage before and after laying in the trench.
c)
VC pipes shall be carefully tapped at mid length and either end with a wooden mallet or, otherwise, a metal bar. This is to detect a clear ring that indicates soundness. This is best undertaken while each pipe is lifted in free air with a lifting sling.
d)
Pipe and fittings shall not be dropped into the trench. Instead, pipes shall be lowered into the trench using approved slings.
e)
Pipes shall be laid from the downstream end towards the upstream end.
f)
The laying of pipes shall proceed carefully to ensure the line, level and grade are within the specified tolerances.
g)
Pipes shall not be dropped or impacted forcefully into the bedding to obtain the specified level or grade.
h)
Concrete pipes with elliptical reinforcement shall be laid with the load line on the vertical axis at the top or bottom position.
i)
Holes made in granular bedding for projections of sockets, flanges, etc. shall be lightly filled where necessary without pushing the pipe/fitting off line, level or grade.
j)
Bedding shall be checked to ensure continuous support along the pipe barrel. Further bedding material shall be placed to an even height and uniformly compacted across the trench to ensure the full support of the pipe haunch.
k)
Pipes that are laid on concrete, grout, cement stabilised bedding or connected to a concrete structure shall consist of a flexible joint at the upstream end immediately outside such a zone.
l)
Pipe level, grade and alignment shall be sighted using sight rails and boning rod or laser and target. They shall be in accordance to the approved longitudinal and cross-sectional sewer profile drawings, which shall be submitted for approval before work at site is allowed to begin.
m)
The invert level of each pipe laid shall be checked during laying and immediately after laying completion, and with reference to the approved drawings.
n)
Boning rods shall have a foot to rest on the pipe invert with a vertical spirit level attached and shall not be more than 45 m apart.
o)
The pipe interior shall be cleaned after laying and kept clean and free of water.
p)
The pipe ends shall be sealed with a tightly fitting plug immediately after laying, cleaning of the pipe interior and at the end of the day after laying.
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3.4.3
3.4.4
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q)
The branch arm of the oblique branch junction fitting, if installed, shall be laid in such a way that it is at approximately 45° off horizontal level.
r)
Junction fittings shall be properly supported using well compacted crushed rock (or, where required, concrete). The coverage of the support shall be across to the trench wall and into the junction trench.
s)
Branch connections shall be sealed with an approved plug where connections are to be made at a later time.
t)
Any pipe laid that is out of alignment either vertically or horizontally or shows undue settlement shall be taken up and re-laid correctly.
u)
Photographs shall be taken during pipe laying and after sewer pipe laying for all lengths of pipes and manholes.
Pipe Jacking a)
Jacking method of pipe laying shall be employed only when the conditions or the requirements of the responsible authorities require such a method.
b)
The pipes used for jacking shall be able to withstand the laterally induced jacking stresses without damage.
c)
The setting out of the guide rails for the pipe and the actual jacking operation shall maintain a high accuracy level of line and grade.
d)
The direction and grade for jacked sewer shall not deviate from the designed alignment for more than 100 mm for every 100 meters of sewer.
e)
All the joints used for connecting the jacked pipes shall be watertight and durable.
Concrete Pipe Support a)
Concrete used shall be 20 MPa Portland cement concrete with a slump no greater than 80 mm.
b)
When purpose-made pre-cast concrete blocks are used, the block shall have approximately the same width as the trench and shall be positioned just behind each pipe socket. A compressible packer of polystyrene or particle board shall be placed between the pipe and the concrete block.
c)
Concrete shall be poured in one lift.
d)
Pipes shall be prevented from floating or other movement during concrete pouring.
e)
A space shall be left between the concrete supports for the pipe socket by use of a polystyrene spacer of 20 mm minimum thickness. This is to retain rotational flexibility at the joint.
f)
The concrete support shall fit the pipe closely after hardening.
g)
Concrete shall be allowed to cure for at least 7 days before applying any load.
h)
Where the trench base is soft or puddly, a blinding layer shall be placed on the trench base before the concrete is placed.
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3.4.5
3.4.6
3.4.6
Pipe Cutting a)
Only VC, HDPE, ABS and DI pipes are permitted to be cut in the field. However prior approval from the Director General is required should the HDPE helically wound profile wall pipe needs to be cut in the field. All pipes shall be cut in accordance to approved methods.
b)
Rough edges and burrs shall be removed from inside and outside of HDPE and ABS pipe with a rasp or file.
c)
Pipes shall be cut in a neat and skilful manner by workers experienced in pipe cutting.
d)
Pipes shall be cut perpendicularly to the pipe axis.
e)
Any damage to the cement lining of DI pipe shall be repaired to the satisfaction of the Commission.
Backfill of Trench a)
Selected excavated material shall be placed above the specified pipe support until 300 mm above the sewer. They shall be in accordance to the approved longitudinal and cross-sectional sewer profile drawings, which also give the bedding details and the types of fill material.
b)
Trench support shall be progressively removed as the backfill is placed.
c)
There shall be at least 300 mm of cover over the sewer before light mechanical compaction can commence.
d)
There shall be at least 1000 mm of cover over the sewer before heavy mechanical compaction can commence.
e)
For plastic pipe, a metallic marker tape shall be laid along the line of the sewer at approximately 500 mm below the surface level.
Other General Requirements a)
Reference shall be made to the approved longitudinal and cross-sectional drawings of sewer profiles of both gravity sewers and force mains. These drawings submitted for approval must include details of bedding types and manhole types, and their design must be must be supported by soil reports.
b)
Pipe laying shall be such that there is adequate access for operations and maintenance of completed sewers, especially in undulating ground profiles, with a minimum width of 6 metres, which shall be supported by drawings with ground profiles during drawings approval stage.
c)
For easy identification of underground forced sewer mains, their layout shall be planted with marker posts at every 200m length and at every change of pipe directions. Valve chambers provided shall have adequate access for operations and maintenance.
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d)
There shall be adequate site supervision of construction, and at least these documents must be submitted before approval of construction:
i. ii. iii. iv. e)
Photographs showing sewer pipe laying during an after construction for all lengths. Testing certificates from the consultants (see Section 4 on Sewer Testing) Supervision certification from the consultants As-built drawings certified by the consultants
The construction and installation works shall incorporate the consideration of health and safety.
3.5
Pipe Jointing
3.5.1
Flexible Joints
70
a)
Joint components (i.e. spigots and sockets or sleeves and rubber seals) shall be checked for damage after delivery, before and after usage.
b)
Every part of the rubber ring shall be bent by hand to detect cracks.
c)
VC pipe sockets shall be gently tapped with a wooden mallet or, otherwise, a metal bar to detect a clear ring that indicates soundness.
d)
Steel sleeve collars used for jacking pipe shall be checked for damage to the coating.
e)
Pipe jointing surfaces and rubber seals shall be wiped clean immediately before jointing using a clean cloth.
f)
The rubber ring shall be placed correctly around the pipe joint.
g)
The rubber ring shall not be twisted in any way prior to jointing and shall be seated in the correct position.
h)
For skid type of joints (i.e. the sealing ring remains stationary and does not roll into place), the spigot shall be lubricated with an approved lubricant.
i)
The pipe to be jointed shall be aligned with the laid sewer before pushing in the joint.
j)
The pipe to be laid shall be orientated so that the offset inside the pipe at the joint is minimise at the invert.
k)
The pipe that is already laid and to be connected to another pipe shall be restrained to prevent its pipe joints being further stressed and to prevent the laid pipe from being pushed off grade or alignment.
l)
Pipe joints shall be connected using a bar and block (crow bar and a block of wood to protect the pipe end) or a pipe puller.
m)
A machine bucket shall only be used to connect a pipe joint where approval is given by the Commission. This method shall only be used for large diameter pipes (larger than 600 diameter pipe) where the jointing compression force makes it impossible to use a bar and block or pipe puller. A timber shall be placed across the pipe end to protect the pipe from
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damage. Pressure shall be applied by the bucket gently while the insertion shall be carefully monitored and directed by a person next to the joint.
3.5.2
n)
No excessive force shall be applied to make the joint.
o)
After pushing the spigot into the socket, the seal shall be checked to ensure the seal is correctly located and the spigot is properly inserted. No contaminants are allowed between jointing surfaces. The joint or pipe shall not have damage from jointing.
p)
Any allowable deflections at joints shall only be made after the pipe jointing is made.
q)
Where a pipe is to be deflected at a joint, the deflection shall not exceed the allowable limit for the specific type of joint.
Solvent Weld Joints a)
The socket and spigot shall be checked for damage before and after jointing.
b)
Damaged spigot ends shall be cut from the pipe with 100 mm clearance to the damage. The spigot end shall be cut perpendicularly to the pipe and any burrs shall be removed.
c)
The spigot shall be inserted up to the wit ness mark.
d)
If a witness mark is not already on the pipe, the mark shall be made to ensure that the spigot is inserted to the appropriate length.
e)
Witness marks drawn on site shall be made with a soft pencil or felt pen marker that would not score or scratch the pipe.
f)
The witness mark shall be of the depth of the socket and shall be measured from the pipe end.
g)
A dry fit of the joint shall be made before the jointing.
h)
Jointing surfaces shall be wiped clean and dried with a clean cloth.
i)
Jointing surfaces shall be primed using an approved priming solution. The priming shall be applied with a clean cloth or swab freshly dipped in the fluid immediately before jointing.
j)
A thin and even coat of solvent cement shall be applied to the socket and the spigot, which should then be inserted up to the witness mark.
k)
The jointing surfaces shall not be contaminated with water, dirt, etc.
l)
The jointing shall be made immediately after the application of solvent cement.
m)
After the spigot is pushed firmly into the socket, the joint shall be hold in the same position for at least 30 seconds without moving.
n)
The jointed pipes shall not be moved for at least 5 minutes after jointing. The jointed pipes shall be handled with extreme care for at least another hour.
o)
Joints shall be left to dry for at least 24 hours before pressure testing.
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3.5.3
3.5.4
72
p)
Containers of solvent cement and primer shall be kept tightly sealed when not in use.
q)
Solvent cement and priming fluid are highly flammable. Therefore, the solutions shall be stored in a cool place away from any source of spark or fire.
Flanged Joints a)
Flanges, particularly flange faces and rubber seal shall be checked for damage before and after jointing.
b)
Appropriate metal backing plates shall be used on plastic flanged pipe.
c)
Screwed-on flanges shall have the screw thread sealed with a compound suitable for sewers.
d)
Flanged ends shall be correctly aligned before jointing.
e)
A steel bar or similar object shall not be used as a lever through the flange holes to bring the bolt holes into line prior to bolting.
f)
The rubber seal between flanges shall be made of an approved compound and shall meet the specified requirements.
g)
The flange faces and the rubber seal shall be wiped clean with a cloth immediately before jointing.
h)
Bolts shall be tightened evenly and gradually in rotation.
i)
Bolts and nuts shall be tightened with a torque trench set at an appropriate torque.
j)
Plastic flanges shall not be distorted before or after jointing.
k)
After pressure testing, metal flanges shall be reprimed and painted with two coats of bituminous based coating in accordance with BS 4147 for below ground protection.
Steel Pipe Welded Joints (Field Welding) a)
The welded joint shall use a socket-spigot joint with taper sleeve wherever possible.
b)
Welding surfaces shall be cleaned to a bright metallic finish before welding.
c)
Welders shall be qualified in accordance with the requirements of British Standard BS 4515 Specification for welding of steel pipelines on land and offshore.
d)
Welding procedures shall be tested, qualified and approved in accordance with BS 4515.
e)
Welds shall be inspected and tested in accordance with BS 4515.
f)
After welding, exposed external surfaces shall be cleaned by sand blasting or wire brushing. The dry surfaces shall be wrapped in an approved manner with an approved wrapping tape to provide corrosion resistance.
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Pol yet hyl en e B ut t Wel ded J oi nt s a)
The pipes to be joined shall be of the same grade of polyethylene and of the same wall thickness.
b)
The butt welding machine shall be of an approved type and shall be fit for use.
c)
The welding machine shall be sheltered from wind and rain during the welding process.
d)
A practice weld shall be performed and discarded to check the operational effectiveness of the machine.
e)
The pipe ends shall be trimmed square.
f)
The ends to be jointed shall be kept free of dirt, grease and moisture after trimming.
g)
The heating plate shall be brought into contact with the pipe ends only after it is at the correct temperature.
h)
The pipe ends shall be held against the heating plate for the specified time appropriate for that pipe size.
i)
Immediately after the removal of the heating plate (no longer than 15 seconds after heating), the pipe ends shall be pressed together with an appropriate pressure for a specified time appropriate for that pipe size.
j)
The joint shall be maintained clamped and pressurised in the machine for a suitable period of cooling time (approx. 10 minutes minimum).
k)
After removed from the machine, the joint shall not be stressed until it has completely cooled (approx. 10 minutes minimum).
l)
The weld shall not be artificially cooled with cold air or water.
m)
The external bead shall carefully be removed. thoroughly checked.
n)
A pipe end that has undergone a complete heating cycle but not joined shall not be reheated. The unjoined pipe end shall be cut off to at least 250 mm from the end.
3.6
Special Requirements For Sewer
3.6.1
Th ru st B lo ck s f or Pr es su re Pi pel in es
The joint zone shall be
a)
The thrust block shall be extended to approximately 180 ° around the fitting.
b)
The thrust block shall not cover a flexible joint.
c)
The thrust block shall be constructed equally around the centreline of the fitting.
d)
The thrust block shall bear firmly against a recess at the side of the trench.
e)
The trench face which the thrust block bears against shall be freshly cut and undisturbed.
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3.6.2
3.6.3
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f)
Each thrust block shall have sufficient bearing area.
g)
Thrust block shall be cast-in-place with 20 MPa concrete.
h)
For plastic pipe or pipe with a protective coating, a compressible membrane of rubber, felt or cork shall be placed on the pipe to protect it from damage from its movement in the thrust block.
i)
Formwork shall be used to cast the thrust block to the required dimensions.
j)
Formwork shall be removed before any testing.
k)
Reference shall made to the standard drawings for thrust block to ensure proper shape and size, which must be designed for each individual thrust blocks.
Pipe Restraints and Bulkheads on Steep Slopes a)
A bulkhead to prevent soil erosion shall be used where the gradient of the sewer is steeper than 1 in 40.
b)
A restraint to prevent sewer slippage shall be used where the gradient of the sewer is steeper than 1 in 6.
c)
The restraint or bulkhead shall be placed at the downstream side of the socket.
d)
Concrete bulkheads shall be keyed into the base and si des of the trench by at least 100 mm.
e)
A weep hole with the upstream end covered with a geotextile filter shall be provided through a bulkhead immediately above pipe invert to allow drainage of groundwater.
Pi pe Embedment and Overlay a)
The embedment material type and its grading shall take considerations of the sewer type or length.
b)
Reference shall be made to the approved longitudinal and cross-sectional drawings of the sewers showing the bedding types, which shall be designed based on supporting soil reports.
c)
Embedment material shall not be contaminated with other soils.
d)
Embedment material shall be brought up evenly in layers on each side of the pipe.
e)
Each embedment layer shall be placed to a depth that permits the compaction equipment to achieve the specified density.
f)
The pipe shall not be pushed off alignment, level or grade while placing the embedment.
g)
Where the embedment requires tamping, tamping equipment shall not come into contact with the pipe.
h)
Temporary trench wall support shall be lifted when the embedment is compacted.
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3.6.5
i)
While placing the embedment for the pipe haunches, unnecessarily voided areas shall be avoided.
j)
At least 300 mm of cover shall be placed over the pipe before light mechanical compaction, such as a hand operated whacker, can commence.
Sleeving of Ductile Iron Pi pe a)
Plastic sleeve shall be secured immediately behind the second spigot jointing witness mark with three overlapping turns of adhesive tape. After that, sleeve shall be tightly wrapped around the pipe by folding over surplus sleeving. Then, the sleeving shall be further secured with three winds of overlapping adhesive tape at one meter intervals.
b)
The pipe shall be placed in the trench with the folding of the sleeve located at the top of the pipe.
c)
After the pipe jointing, the sleeve of the preceding pipe shall be brought over to cover the socket and the cover shall follow the socket outer surface closely.
d)
The sleeve of the preceding pipe shall overlap the sleeve of the next pipe. The sleeve overlap shall be secured with three overlapping winds of tape.
‘ Ro cker ’ Pi pe Co nn ec ti on s t o Man hol es a)
3.7
The ‘rocker’ pipe connecting sewers to manholes shall have sufficient cast insitu concrete surround and extended concrete base as shown in typical manholes drawings in Appendix A.
Reinstatement a)
All structures, services, fences, drains, gardens, improved surfaces, etc. disturbed by the construction shall be restored within 7 days after backfilling. The restored conditions shall be as similar as possible to their original condition. Also, the condition shall be to the satisfaction of the Commission, other responsible authorities and property owners.
b)
Where a structure or service is affected by construction, the trench fill shall be compacted to the equivalent of that under a pavement.
c)
Within 7 days after backfilling, fill over unimproved surfaces shall be placed to a height that will make the filled surface level and the adjacent undisturbed surfaces closely matching after settlement. All contours shall be similar to the original condition.
d)
Unimproved surfaces shall be levelled and settled to as near as possible to their original condition in 30 to 40 days after backfill.
e)
Road pavements and access ways shall be temporarily restored to a safe condition, immediately after completion of backfilling. Then, the pavements shall be permanently restored to as similar as possible to their original condition within a time frame specified by the responsible authority.
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f)
Extra excavated material, un-reusable excavated material and all rubbish shall be removed from the site and legally disposed of.
3.8
Connections to Public Sewers
3.8.1
General Severe maintenance problems are often caused by poorly made connections to sewers. These may lead to blockages or failure of the sewer structurally. The following procedures and formalities must be followed to ensure integrity of the sewerage system.
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a)
The owner must seek the approval of the Director General for any connections that involve physical work to an existing public sewer. The initial notification must be made on the appropriate form.
b)
Once approved, the owner may make the connection only if his contractor is licensed by the Commission for this category of work.
c)
The type and location of connections shall be determined by the Commission. The type of connection could be a connection to a manhole or a connection to a sewer through junction or saddle fittings.
d)
The cost of the work in making the connection shall be borne by the owner, regardless of whether the work is undertaken by his licensed contractor or a licensed contractor employed by Services Licensee.
e)
The connection must be correctly made by the licensed contractor under the supervision of an authorised inspection person.
f)
When the connection is ready for inspection, the owner must notify the Commission on the appropriate form. At the same time, he must give a copy of the notice to the authorised inspection person who will make arrangements for the inspection.
g)
The connection must be completely watertight to prevent infiltration. Any evidence of infiltration in the connection pipe shall be referred to the Local Authority who may withhold issuing the Certificate of Fitness.
h)
For a development which contains several connections from individual premises to the proposed public sewers within the development, the connections may be deemed covered by the original technical proposals. These individual connections will be inspected as part of the routine inspection by the authorised inspection person.
i)
The inspection by the authorised inspection person for the connections to existing public sewers shall be subjected to a standard inspection fee.
j)
The design and installations shall incorporate the considerations of health and safety
k)
The difference between each premise platform level and the nearest public sewer invert level shall not be less than 1.2 metres to avoid flooding of premises.
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3.8.2
Junction Connections Where an existing public sewer is circular and is of diameter DN 450 or less, any connection to that sewer may be made using a Y junction fitting. Where the location of future connections are known, Y Junction fittings and the accompanying junction connection pipework may be installed at the time of the public sewer construction. The typical connection configuration of junction is shown in Figures A.11 and A.12 of Appendix A. Where no junction pipework exists, a Y junction fitting may be installed by removing part of the existing sewer. The connection of such a junction shall use flexible couplings.
3.8.3
Saddle Connections Saddle connections may only be permitted where the existing sewer is at least two pipe sizes greater than the proposed connection pipe. Only saddles specifically designed for the type and size of the sewer to be connected to shall be used. Also, the saddle used shall be approved by the Commission. Making a saddle connection is a highly skilled operation. Hence, only licensed contractors who can demonstrate suitable qualifications and experience are permitted to make this form of connection. The saddle must be purpose-made by off-site manufacture except when the existing pipe size is 900 mm in diameter or greater, which other forms of connection are preferred. The saddles for concrete or vitrified clay sewers shall be bedded on cement mortar (mix 3:1) with a depth not less than 40 mm below the base of the saddle. A flexible joint shall be provided between the saddle and the remaining connection pipe. The hole prepared for the saddle connection on the existing sewer shall not have any rough edges that might cause blockage. The location of the hole on the pipe shall be at a 45° to 60° angle to the horizontal. The hole shall be made at the middle of the pipe to avoid damages or excessive loading to the existing sewer pipe joints. The existing pipe may require extra strengthening by additional concrete surround to withstand the extra load from the connection pipe and fittings. The connection pipe must not protrude into the existing sewer. Any debris falling into the existing sewer during the connection shall be removed. On completion, the saddle connection joint must be completely watertight to prevent infiltration.
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3.8.4
Manhole Connections Manholes may be constructed on the public sewer for private sewer connections where: a)
good practice requires a manhole for ease of maintenance, or
b)
the diameter of the connection pipe is 300 mm or greater, or
c)
the public sewer is more than 4.5 m deep, or
d)
the point of connection is more than 5 m from an existing or proposed manhole.
Where site conditions prevent manhole construction on the existing public sewer, the manhole may be provided on the connection pipe as near to the public sewer as possible.
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Secti Section on 4 Sewer Sewer Test Testin ing g
Sewer Testing
4.1
Gen er al Sewers and ancillary works shall be tested and inspected for water-tightness to prevent infiltration and exfiltration and to ensure the pipe are laid correctly according to the designed straightness and grade. The testing of the sewers and ancillary works before backfill will facilitate the replacement of any identified faulty pipes and joints. The testing of the sewers and ancillary works after backfill will reveal the leakages caused by the displacement of joints and subsequent damage. The testing shall be supervised by consultants and their testing certificates issued by the consultants shall be submitted to the Commission before final approval. The tests that are required to be conducted are listed as follows:
I)
Before Backfi ll
a)
Gravity Sewer:
b)
c)
i.
Exfiltration Test (Either low pressure air or water tests)
ii.
Check for straightness, obstruction and grade
Force Main:
i.
Exfiltration Test (When required)
ii.
High pressure water test
iii.
High pressure leakage test (Following high pressure water test)
iv.
Check for straightness, obstruction and grade
Manhole and others:
i.
Visual inspection
ii.
Water-tightness test (when required)
To prevent movement of the sewer, embedment material shall be placed around and over the sewer prior to testing. The section of the joints above spring line shall be exposed. For pipe or part that is made of material that will deteriorate under the sun, the exposed parts of the pipe shall be shielded from direct exposure to the sun during testing. The concrete used for supporting the pipe or resisting thrust shall be cured for at least seven days prior to testing.
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II)
After Backfill
a)
Gravity Sewer:
i)
Exfiltration Test (Either low pressure air or water tests)
ii)
Infiltration Test (when required)
iii)
CCTV Test (when required)
Before and after any test, the sewer pipeline to be tested shall be clean, which shall be flushed clean when necessary. Any leaks or defects identified from any test shall be located and repaired. After testing has been completed, the cleaned sewer shall be plugged at open ends to prevent dirt or soil from getting into the sewer.
4.2
Testing of Gravity Sewers The tests of gravity sewers are generally conducted to ensure there is no leaks, damages, or laying errors. An exfiltration test, which can be either a low pressure air test or a water test shall be performed on the sewer before any concrete pipe encasement or backfill. After backfilling, an exfiltration test is required again on the sewer laid. In addition, an infiltration test shall be conducted if: a)
required by the Commission
b)
detected high groundwater table
When infiltration has been confirmed by the infiltration test, light and mirror method or CCTV may be used to isolate the locations of leaks. If a CCTV inspection is conducted, a video and written record of the CCTV inspection shall be provided to the Commission no later than 7 days after the inspection. For gravity sewers, the sewer length to be tested shall be the length between manholes or proposed manhole locations. The test length for water test may be shorter where the gradient is so steep as to cause too high a head at the downstream end. The pressure head on the sewer being tested shall not be less than 2 m above pipe crown at the upstream end and shall not be more than 7 m above pipe crown at the downstream end. When desired, the air and water tests may be undertaken on shorter lengths of the laid sewer before backfill. This is to prevent any faulty joint to go unnoticed until it is revealed by a test on the complete length, which will be more costly and time consuming to rectify the defects. Testing of shorter lengths may also be necessary where it is required to backfill the sewer to surface level quickly. This early backfill may be encountered when there is wet weather, traffic crossings or site safety requirements. In every stage of the works, frequent tests of straightness and obstruction shall be conducted, when required, to ensure there is no line obstruction and the straightness or grade is correct.
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4.3
Testing of Forced Mains For pressure sewers, the normal tests during the sewer laying may include, where required, the low pressure air or water exfiltration t ests on short individual sections. These low pressure air or water exfiltration test are conducted, when required, to ensure that the joints are watertight. As in gravity sewers, the force mains should be checked to ensure the straightness is correct and to ensure no obstruction in the force mains. Also, force main is required to be tested for its mechanical stability through the high pressure water test. Its water-tightness shall be tested through high pressure exfiltration test. Before conducting these high pressure tests, the sewer support and thrust block shall be allowed to develop the sufficient strength. In addition, cautions shall be taken when dealing with high pressure. Where required, a CCTV inspection should be performed on the pipeline after backfilling the trench. If a CCTV inspection is performed, a video and written record of the CCTV inspection shall be provided to the Commission no later than 7 days after the inspection. For the high pressure water test, the test length will depend on:
a)
the length which can be isolated effectively, i.e. suitable anchorage for temporary end closures
b)
the time permitted to leave the trench open without backfill taking considerations of weather, safety, traffic etc.
c)
the location of permanent anchorages
d)
the maximum volume of water available to fill the pipeline
e)
the requirement to have the pressure at the highest point not less than 0.8 times the pressure at the lowest point
After taking the above considerations, initially a maximum of 300 m length of pipe shall be laid and tested to verify that pipe laying practices are to an acceptable standard. The maximum lengths for subsequent tests may be progressively increased, as determined by the authorised inspection person, but shall not exceed 1500 m.
4.4
Tes ti ng o f Man ho le an d o th er an cil lar ies Manhole and other ancillaries shall be constructed in such a way that no appreciable amount of infiltration or exfiltration will occur. When the manhole and other ancillaries are constructed in an effective manner, visual inspection is normally sufficient. However, manholes and other ancillaries suspected of very poor workmanship shall be tested with exfiltration test before backfill or concrete surrounded.
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Sewer Testing
Connections between sewer and manholes shall be constructed with extended castin-site concrete base and surround over the top of the rocker pipe in accordance to the standard drawing attached. Drop manholes shall be constructed in such a way that no appreciable amount of blockage will occur with construction details as in the standard drawings which provide for proper pipe outlets and proper sizing of drop pipes. A visual inspection is required on all the external and internal sections of each manhole before backfill. Particular attention shall be given to:
a) b)
the slope of benching, joints to pipes,
c)
transitions at entry and exits,
d)
joints in the structure
e)
quality of concrete finish
f)
water-tightness of manhole cover and surround.
The internal surfaces of manholes shall be inspected visually for sources of infiltration after backfill and stabilisation of groundwater table. Manhole covers and surrounds shall be checked for leakage of surface water.
4.5
Low Pressure Air Test
4.5.1
General Low pressure air test is one of the two sewer exfiltration tests recommended for sewer testing. The air test is quicker to conduct than the water test. Furthermore, no large quantity of water needed to be disposed of after the test. This test provides a quick mean for checking any damage pipe or joints. Sometimes the test is conducted on a short length to prevent damage pipe or joints from passing without noticed until the final sewer test, which could be more costly and time consuming to rectify. However, these tests on the shorter length should not replace the final test.
4.5.2
Procedure for Testing a)
Seal the open ends, including sideline ends, using approved plugs. Strut the plugs to prevent movement. Provide temporary bracing where necess ary to prevent pipeline movement during testing. (One of the end plugs will require a connection point to permit injection of air.)
b)
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Connect a hand or motorised pump to the pressure injection line at the end plug. Pressurise the test length at a slow and constant rate.
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c)
Use dial pressure gauges to measure pressure. Apply an air pressure of:
i.
30 kPa for vitrified clay and reinforced concrete pipelines
ii.
50 kPa for all other pipelines
(Two gauges in series shall be used so that the accuracy of one gauge can be confirmed by the other. The dial gauges shall be able to be read to an accuracy of ± 0.1 kPa.)
d)
Wait five minutes for air pressure to stabilise due to temperature absorption into pipe wall and other effects. Adjust the pressure to the required test pressure during this period.
e)
Check for leaks at plugs and test apparatus. Release the air pressure where leakage occurs. Make necessary repairs and adjustments of apparatus to prevent leakages. Repressurise the sewer pipeline in accordance with the preceding steps again.
f)
Start the test and record the pressure loss for the test duration after the final gauge adjustment to the test pressure. Conduct the test for the test duration given in Table 4.1.
Table 4.1 Test Duration Pipeline Nominal Size 150 225 300 375 450 525 600 g)
2 4 6 8 11 14 17
Pass the test if the pressure loss over the test duration does not exceed: i) ii)
4.5.3
Test Duration (minutes)
7 kPa for vitrified clay and reinforced concrete pipes 2 kPa for all other pipes
Pr oc ed ur es fo r Han dl in g A ir Tes t Fai lu re I)
Before Backfill
a)
Readjust the pipe pressure to the specified test pressure and examine for leakage by pouring a solution of soft soap and water over the exposed joints if the test fail.
b)
Repair leaks and repeat testing where leaks are found at joints.
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c)
Where leaks are not found at joints, move the plug, the one that is not used to exert air pressure, along the pipeline to isolate lengths with leakage. Uncover pipe barrels in the isolated lengths where leakage in pipe barrels is suspected. Replace leaking pipe lengths and repeat testing.
d)
Conduct low pressure water testing to verify that the air test was not erroneous where the test length fails the air test but no source of leakage can be identified.
II)
After Backfilling:
a)
Move the plug up from the other end along the sewer pipeline to isolate the lengths that fail the air test.
b)
Exhume the failed length of pipeline and replace pipe lengths.
c)
Repeat the air test.
d)
Conduct water testing to check that the air test was not erroneous when failed lengths could not be isolated using the air test.
e)
Use CCTV, when required or available, to identify the leakage if the fail section can not be isolated by the air test or water test.
4.6
Low Pressure Water Test
4.6.1
General The low pressure water test is commonly used for checking the water-tightness of the joints and the integrity of the sewer pipes. Unlike the high pressure water test, this test can not be used to check the mechanical strength of the sewer pipe. Compared with low pressure air test, this test requires more time to set up the test. Also, the water used for the test require disposal in an appropriate manner. However, this test will show the location of the leaks more clearly than the low pressure air test.
4.6.2
Procedure a)
Seal the open ends, including sideline ends, using approved plugs. Strut the plugs to prevent movement. Provide temporary bracing where necess ary to prevent sewer movement during testing.
b)
Establish appropriate arrangements involving a standpipe to apply the water head at the upstream end. (Acceptable arrangements include:
i.
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temporarily fitting a 90 ° bend to the upstream end, which should then be connected with a vertical riser of straight pipe to used as a standpipe
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Sewer Testing
ii.
sealing the upstream end with a plug which has a connection point for a hose, which can be connected to a tube acting as a standpipe)
d)
Fill in water from the upstream end. Ensure water head is not less than 2 m above pipe crown at the upstream end and not greater than 7 m above pipe crown at the downstream end. Shorten the test length if the sewer gradient is so steep as to cause these water head requirements not to be met.
e)
Fill the sewer slowly to the required head and bleed air from behind the upstream plugs. (Air may be released by slightly loosening the plug and pushing in a piece of wire between the seal and the pipe.)
f)
Maintain the water head for two hours. Top up the water as required.
g)
Check for leakage at the plugs and the test apparatus during the pressurising period and the constant pressure holding period. Release the water pressure if leakage occurs. Make the necessary repairs and adjustments before repressurising again.
h)
Commence the test immediately after the last adjustment of water head in the preceding two hours period.
i)
Add water to maintain the starting water head every 5 minutes during the test period of 30 minutes. Record the total amount of water required for readjustment.
j)
4.6.3
Pass the water test if:
i.
the loss of water does not exceed 1 litre per hour per linear metre per metre internal diameter for vitrified clay and reinforced concrete pipes,
ii.
there is no loss of water for pipe other than vitrified clay and reinforced concrete pipe,
iii.
these is no visible leakage at the joints for all pipe types.
Han dl in g Wat er Tes t Fai lu res I)
Before Backfill:
a)
Readjust the internal water head to the specified test head if the test section fails the water test. Examine visually for leakage at the external surface of joints.
b)
Uncover pipe barrels and inspect for leakage if leakage is not evident at joints. Drain the water and move the downstream plug towards upstream, where necessary, to isolate pipe lengths that fail the water test.
c)
Repair or replace pipes before repeating the low pressure water test until the sewer passes the test.
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II)
A f t er B ac k f i l l :
a)
Isolate pipe lengths that fail the water test by moving the downstream plug towards the upstream end in sections when the test sewer fails the water test. Alternatively, conduct a CCTV inspection, where required, to identify the source of leakage if the source of leakage can not be isolated.
b) c)
Exhume failed pipe lengths and replace. Repeat test until the sewer pipeline passes the test.
4.7
Hi g h Pr es s u r e Wat er Tes t
4.7.1
Gen er al High pressure water test is normally used for testing the pressure sewers and pipe works within the pump station. The main aims of the test are to ensure the mechanical stability of the pipe and joints to withstand the working working pressure. Since the test is conducted under high pressure, the anchorage of the sewer is more critical than the low low pressure tests. Preferably, the test should be conducted before before backfill. During the test, the test pumps should not be subjected to hydrostatic pressure.
4.7.2
Pr o c ed u r e a)
Seal the sewer pipeline ends using “test-end” units consisting of short lengths of pipe permanently fitted with caps or valves. Connected the “testend” units to the test pipe section using a standard coupling, which permits easy removal of “test-end” units after testing. (The “test-end” units should have a valve with pressure gauge to allow filling of the test length with water or for venting air. The gauge shall be a conventional circular gauge not less than 200 mm diameter and shall be able to read to an accuracy of ± 0.01 Mpa.)
b)
c)
For sewer on level grade, fit tees along the test length, where necessary, to ensure all the air can escape. Fit air valves to such tees. Remove air valves and blank off tees after the test is applied. Fit the test pressure gauge at the lowest end of the test length. (This prevents the test pressure from exceeding the permitted maximum pressure in the test length.)
d)
Place pre-constructed temporary thrust blocks behind the test end units to brace against thrust from the test pressures. (No temporary bracing is permitted permitted along the sewer pipeline. All specified thrust blocks must be constructed and left to cure before testing.)
e)
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Fill the test length slowly with water through the valve at the lowest testend unit.
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(The water shall be be of fair quality quality and free from from sediment. A firm foam swab placed ahead of the water column will improve the expulsion of air.)
f)
Set all valves at high spots to vent air.
g)
Close the air vents after thorough venting of all air.
h)
Fill the test length with water. Leave the filled test length undisturbed for 24 hours prior to testing to allow for absorption of water into the pipes and /or jointing materials.
i)
Wipe the exposed fittings and joints clean and dry and check for leakage and other irregularities during this preparatory period. Check also the test pipe for any appreciable movement and disturbance of anchorages. Drain the water and repair any damage damage found. Repeat the water filling again to start the test.
j)
Pump more water into the test length to raise the pressure. Raise the pressure slowly in increments of 1 bars, with pauses of one minute between each increment until achieving the lower of:
i.
the maximum rated pressure of the pipes laid, or
ii.
1.5 times the design operating pressure of the pipeline (includes surge allowance)
k)
Stop the test immediately should any appreciable drop in pressure be noted during one of these pauses. Determine the cause of the pressure drop. Drain the test length where repairs are required. required. Start the test again again after repairing.
l)
Pass the pressure test if there is no reduction from the test pressure in the next 10 minutes after the test pressure pressure is achieved. Do not reduce reduce the pressure since the high pressure leakage test should be conducted immediately next.
4.8
Hi g h Pr es s u r e L eak ag e Tes t
4.8.1
Gen er al High pressure leakage test normally follows the high pressure water test immediately. This is to avoid any unnecessary pressurising and water filling, which could take time and is costly. The purpose of this test is to ensure the pipe and joint will remain intact under the pressure environment.
4.8.2
Pr o c ed u r e a)
Conduct the test immediately after the high pressure water test. Maintain the following test pressures (whichever is lower) for 24 hours by pumping in make-up water if necessary:
i.
the maximum rated pressure of the pipes laid, or
ii.
1.5 times the design operating pressure of the pipeline (includes surge allowance)
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4.9
b)
Measure the amount of make-up water pumped into t he pipe to maintain the test pressure.
c)
Pass the test if the measured amount of make-up water does not exceed 0.1 litre per millimetre of pipe diameter per kilometre of pipe per day for each 3 bars of pressure applied.
d)
Reset the test pressure and check all visible joints to locate leakage when the test length fails the test.
Tes t f or or St St ra rai g ht ht ne nes s, s, Ob s tr tr uc uc ti ti on on , an d Gr ad ad e The sewers shall be check for straightness, obstruction, and grade whenever possible. For gravity sewers and force mains, the grade and straightness are important to achieve the designed velocity. The following tests are recommended for testing the laid sewer:
I)
Tes t f or or f re reed om om f ro ro m o b st st ru ru ct ct io io n :
a)
Visual inspection
b) c)
Insertion of mandrel CCTV inspection
It should be noted that the visual inspection is only for checking a short length. Sufficient light shall be provided provided when carrying out the inspection. For checking a long sewer, insertion of a mandrel should be adopted.
II)
Tes t f or or gr gr ad ad e an d s tr tr ai ai gh gh tn tn es es s
a)
Laser beams with sighting targets
b)
Sight rails and boning rods
c)
CCTV inspection
d)
lamp and mirrors
e)
Insertion of a smooth balls
The first three methods will provide a more exact assurance for both the grade and straightness of sewers, which shall be used whenever possible. The latter two methods will provide a rough ideas on whether the sewers are laid graded or straight, which should be used only for a quick check.
4.10
CCTV In s p ec t i o n The following subsections outline details on how the CCTV inspection requirements shall be implemented. These guidelines are also aim to enhance professionalism in line with progress in sewerage field, and promote efficiency and
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cost effectiveness as well as transparency and accountability in sewerage system development.
4.10.1
Objectives of CCTV Inspection a)
Enable detection of sewer defects such as cracks, deforms, collapse, dislocate and etc. which are not detected by normal means;
b)
As a quality assurance measure to ensure sewers and sewer appurtenances are constructed in conformability with approved design, specifications, workmanship as well as materials and fixtures used;
c)
4.10.2
As a means to establish record to enhance accountability professionalism on quality assurance for sewer construction.
and
Technical Requirements and References a) b) c)
Analysis of defects shall be based on WRc Manual for Sewer Condition Classification Latest Edition; Equipment and test devices to be used are as listed in Section 4.10.3. For sewer with diameter larger than 1050 mm, Man-entry CCTV survey mode may be adopted unless it can be demonstrated that the CCTV can be maintained in a stable position on or near the central axis of the sewer and images captured are satisfactory and not distorted.
4.10.3
Equipment Specifications and Test Devices
4.10.3.1
Specifications for CCTV unit’s equipment a.
Solid state colours CCTV camera with pan & rotate features, together with a lighting unit, automatic date/ metre age.
b.
A self powered tractor or crawler on which the camera is conveyed along a pipeline under inspection in a stable manner.
c.
Calibration chart for various sizes of sewer for the camera used.
d.
Test device for the CCTV camera using 'Marconi Resolution Chart No.1' or its derivative to demonstrate satisfactory performance of the camera.
e.
Test device for the monitor and video recorder to establish the effectiveness and accuracy of the 'on-site' monitor and video recorder.
f.
The control unit comprises the camera unit, crawler control and screenwriter. This console can be mounted permanently in a vehicle or use as portable system.
g.
A video recorder for recording high quality video images.
h.
A means of producing still images from the monitor screen.
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i.
4.10.3.2
A PC-based site reporting system capable of producing reports customized to the Contractor's needs and to include photographs captured directly from video.
Soft ware Requir ements Software standardisation using databank software that can produce report, based on WRc format.
4.10.3.3
Report Format Report in VCD or other digital form to be submitted in MPEG format with minimum 352x240 pixels. Two copies of digital records and one copy of hardcopy report shall be forwarded to JPP office.
a)
4.10.4.
For the diameter pipe greater than 600mm, it shall have zooming capabilities.
CCTV Inspection Requirements The following areas area identified as the minimum coverage for CCTV inspection.
4.10.4.1
High Risk Areas A 100% CCTV inspection shall be conducted for sewers laid in the ground with high risk of failure and having the following characteristics:
a) b)
4.10.4.2
Pipe diameter above 600mm.
c)
Areas that have restricted vehicular access for repair (e.g. central business district).
d)
Crossings under buildings, lakes, rivers, roads and railway including their reserve.
e)
Ground slopes greater than 30 o inclination.
f)
All sewers installed using pipe jacking method.
g)
All diversion or re-alignment of existing sewer networks.
h)
All single private developments (with PE > 30), connecting to existing main sewer.
General Inspection Coverage (for Sewer, Manholes and Lateral Connections) a)
90
Deeper than average 6m or more
Initial CCTV testing & inspection shall be conducted for a minimum 10% random selection of sewers including all manholes and lateral property connections in accordance with standard procedure.
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4.10.4.3
b)
If the mandatory requirement of Clause 4.10.4.1 is less than 5% of the entire development area, the minimum CCTV testing & inspection is 10% as in Clause 4.10.4.2a. If the mandatory requirements of Clause 4.10.4.1 is more than 5%, the minimum CCTV testing & inspection shall have an additional of 10%.
c)
Prior to taking over existing network that has been approved from any owner or after rehabilitation works have been completed.
d)
All new network undergoing intermediate inspection except:
i.
Single Phase development with total sewer length less than 500m long with no interval.
ii.
Vacuum sewer.
Stage of Inspection a)
Stage 1- All projects are to start with stage 1 inspection where 10 % (by length) of sewer network and property connections involved, shall be randomly selected and CCTV inspected.
b)
Stage 2 - Should any Grade 3,4 or 5 conditions as defined in the Manual for Sewer Condition Classification approve by the Commission, found in Stage 1 inspection, the CCTV inspection shall proceed to Stage 2 inspection. Stage 2 inspections shall include another 40% of the sewer network to be randomly selected for CCTV inspection.
c)
Stage 3- Should any Grade 3,4 or 5 conditions as defined in the Manual for Sewer condition classification approve by the Commission, found in Stage 2 inspection, the CCTV inspection shall proceed to Stage 3 where all the remaining network shall be CCTV inspected.
4.10.5
CCTV Inspection Implementation Procedure for New Sewer Network
4.10.5.1.
Activities to be completed Intermediate Inspection. a) b) c)
4.10.5.2.
before
submitting
for
final
All construction works have been completed and tested by the supervising qualified person. Sewer networks have been cleared of debris and are ready for inspection. A CCTV Inspection Contractor licensed with the Commission has been appointed to carry out the inspection.
Random selection of sewer to be insp ected. a)
The list of sewer segments and house connections selected for CCTV inspection shall be recorded and the parties witnessing the selection process shall duly sign the record.
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b)
c)
4.10.5.3.
4.10.5.4.
The random selection process shall be completed in a single session.
CCTV inspect ion on site. a)
The CCTV inspection shall be carried out 7 days after notice issued by the Commission.
b)
Inspection shall be carried out in within 24 hours after random selection has been completed.
c)
Once started, CCTV inspection for a project shall be carried out without any break. Should for any reason a break/delay of more than 24 hours become necessary, the random selection process shall be repeated to select the remaining sewer segments for the inspection. Reasons for the break/delay shall be recorded.
d)
Representative from the Commission or authorized person, consultant representative and contractor responsible for the construction of the sewer shall be present at the onset of CCTV inspection at each project site.
Documentation on CCTV recording a)
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Names and designations of all persons involved in the random selection process as well as the time, date and place where the selection were carried out shall be recorded in the report on the random selection process. Record of the sewer segments randomly selected for CCTV inspection shall be included as appendix to the report.
At the start of the CCTV recording, the following details must be recorded:
i.
Date and starting time of inspection.
ii.
Project name and location
iii.
Names and designation of persons involved (i.e representative of the Commission or authorized person, consultant & contractor and CCTV contractor).
b)
At the beginning of each CCTV recording for every segment of sewer shall be marked with their respective code number with chainage together with the date, start and end times of the recording.
c)
After the CCTV inspection and recording have been completed for a project, a copy of recorded CCTV shall be handover to the Commission or authorized person immediately. Report on the CCTV inspection together with the recording and recommendations shall be prepared by the CCTV contractor and submitted to the relevant the Commission branch office or the appointed agency not more than 7 days after the date of inspection. The format of reporting shall follow the standard that had been given (Appendix C). The copy of the tape (or other recording media used to store the record) containing the CCTV inspection records shall be submitted to the Commission Branch office or the appointed agency together with a certificate duly signed by the qualified person responsible for the CCTV inspection declaring the authenticity of the recording submitted and that the
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CCTV inspection has been done in accordance with the procedure stated in this guideline.
4.10.6
Interpretatio n of Result s fro m CCTV Inspectio n a)
4.10.7
Classification : Grade 1 to Grade 5 as per the Commission approve Sewer Assessment Classification. Colour to show the defect grade description shall be follow as:
i.
Grade 1: Green
ii.
Grade 2 : Blue
iii.
Grade 3 : Orange
iv.
Grade 4 : Brown
v.
Grade 5 : Red
b)
Grade 1 and 2 is acceptable constructional defects but may have other minor defects. It can be accepted provided a performance bond has been submitted and the contractor undertake to rectify the defect within 30 days.
c)
Sewer with Grade 3, 4 or 5 conditions has major structural defects and shall be accepted. Relaid of the affected sewer segments is necessary.
Fo ll ow -Up Ac ti on to Be Tak en a)
For Grade 1 and Grade 2, the developer shall rectify and make good to all the defects in 30 days. These rectification works shall be witnessed by the parties concerned and agreed together that the works had been completed. The Commission or the authorised person may instruct CCTV inspection to be carried out again. Under these grade classifications, the letter of recommendation for CFO will be released by the Commission or the authorised agency.
b)
For Grade 3, 4 or 5 classifications, the developer shall change, replace, relay or reconstruct the rejected works. Further CCTV inspection shall be carried out before acceptance. The letter of support for CFO will be released upon acceptance.
c)
In the events of any blockages, damages, seepages and etc to the sewer networks during the defects liability period, JPP may require the developer to carry out further CCTV inspection to determine the cause and extent of the problems that arises. CCTV inspection shall be carried out immediately within 24 hours.
Table 4.1 provides the description of various defect grades
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Table 4.2 Defect Grades Descriptions
Grade 1
Occurances without damage and no cracks of pipe but only acceptable displacement on joint where no visual infiltration can be observe: e.g.
Grade 2
Constructional and sewer product deficiencies or occurances with insignificant influence to tightness, hydraulic or static pressure of pipe, etc. Examples: Joint displaced large; badly torched intakes; minor deformation of plastic pipes (5%); Lining defect.
Grade 4
Constructional and structural damages with no sufficient static safety, hydraulic or tightness. Examples: axial/radial pipebursts; visually noticeable infiltration/exfiltration; cavities in pipe-wall; severe protruding; laterals severe root penetrations; severe corrosion of pipe wall; Infiltration running; encrustation medium; minor deformation; flexible pipe deformation >15%
Grade 5
Major structural damaged where pipe is already or will shortly be impermeable. Examples: collapsed or collapsed eminent; major deformation; deeply rooted pipe; any drainage obstructions; pipe loses water or danger of backwater in basements etc
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4.11
Infiltration Test
4.11.1
General Infiltration is an extraneous flow not contributed from households. Although design has allowed for certain amount of infiltration, a significant amount of unexpected infiltration will overload both the collection sewers and the treatment plant. To avoid any extra infiltration, a test maybe conducted on the gravity sewer laid. If the force main is significantly below the groundwater table, an infiltration test is also highly recommended. When severe infiltration is found during sewer laying, the source shall be investigated immediately. Infiltration test is normally conducted after backfill and after the groundwater level has stabilised. The procedures are as follows:
4.11.2
4.11.3
Procedure a)
Plug the inlets at all upstream open ends, after the groundwater level has stabilised following backfilling.
b)
Measure any infiltration from the sewer to the manhole or within manhole itself.
c)
Conduct the measurement of infiltration for at least 24 hours.
d)
Pass the infiltration test if the infiltration does not exceed 1 litre per hour per metre diameter per meter of pipe run.
Han dl in g Tes t Fai lu res a)
Conduct a light and mirror test to identify the location of the infiltration if the pipe is small and short.
b)
Move an inflated rubber plug toward downstream end to isolate lengths of leakage. Repeat the test procedure after each plug relocation
c)
Conduct a CCTV inspection if the location of the infiltration can not be identified by the light and mirror test or moving the inflated rubber plug.
d)
Exhume and repair the fail section of the pipe.
4.12
Water-tightness Test
4.12.1
General Visual inspection is usually sufficient to ensure the water-tightness of manhole and other ancillary structures. However, water-tightness test may be required if: a)
Instruction from the authorised inspection person
b)
Unsatisfactory features identified from the visual inspection
c)
Suspicion of poor workmanship or poor materials
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d)
Leakages revealed from other tests
e)
Frequent surcharging of the structure is possible
The test should be carried out only after the structures have achieved sufficient strength to withstand the test pressure. Where possible, the test shall be carried out before backfilled or concrete surrounded. For manhole less than 1.5 m in depth, the manhole shall be filled with clean water to the bottom of cover. For manhole more than 1.5 m in depth, the water head for the test shall not be less than 1.5 m or the mean groundwater level, whichever is larger. For any other ancillary structure, the water shall be filled to the top of the structure unless otherwise specified by the authorised inspection person. The procedures for testing the manhole are listed below. For other ancillary structures, the procedures can still be adopted. However, the height which the water level should be tested shall follow the instruction from the authorised inspection person.
4.12.2
Procedures a)
Fit a plug or stopper in all the openings.
b)
Secure the plug/stopper to resist the full test pressure.
c)
Provide a mean to remove the plug/stopper from the ground level safely if test water is allowed to be discharged to the downstream. (The plug/stopper may need to be remove while the structure is still full of water. Alternatively, a potable submersible pump might be sunk into the test structure to remove the water.)
96
d)
Fill the structure with clean water. Fill slowly to avoid any intense pressure impact from the water.
e)
Observe visually to identify any water leakage to the outside of the structure. Drain the water to repair the leakage if necessary.
f)
Otherwise, allow the water to stay in the test structure for 8 hours. Investigate any appreciable water loss.
g)
Drain and dispose of the test water from the test structure in an appropriate manner and to an suitable location.
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APPENDIX A
Appendix A
APPENDIX A
Figure A.3
:
Standard Precast Concrete Manholes (Shallow, 2.5 to 5 metres, and > 5 metres depth): Add standard drawing for large diameter manhole with RC chamber. Page 107.
Figure A.4
:
Standard Precast Concrete Manholes (Shallow, 2.5 to 5 metres, and > 5 metres depth): Add standard drawing for large diameter manhole with RC chamber. Page 108.
Figure A.5
:
Standard Deep Precast Concrete Manhole: Remove or reposition landing for clear passage from manhole top, as landing may obstruct operations activity (eg. jetting hose).Page 109.
Figure A.5
:
Standard Precast Concrete Manholes (Shallow, 2.5 to 5 metres, and > 5 metres depth): Add standard drawing for large diameter manhole with RC chamber. Page 109.
Figure A.6
:
Standard External Drop Junction: Present susceptible to blockage. Improve construction details to minimise blockage Page 110. a.
Outlet for 90 deg bend pipe, to raise to min. 300 mm above crown of sewer pipe.
b.
Size of drop pipe min. 300 mm dia.
Figure A.13 :
Typical Induct Vent Detail: Delete this figure, as not applicable. Page 117.
Figure A.14 :
Typical Details of a Wet Well Submersible Pump Station: Review, include also typical details not using the circular wet well type (which is now not common). Page 118.
Figure A.18 :
Buffer Zone for Pump Station with and without Super Structure: Buffer zone for fence to fence, add note “where located in high risk areas, brickwall fencing may be specified for safety”. Page 122.
Figure A.19 :
Buffer Zone for Pump Station with and without Super Structure: Buffer zone for fence to fence, add note “where located in high risk areas, brickwall fencing may be specified for safety”. Page 123.
Note: Other figures added are distributed as hard copies for incorporation in the documents.
OTHER COMMENTS
a)
Clause 2.5.2, 1 (Oil & Grease Trap) - Drawings submission by developers must show O&G traps have been provided for these premises where grease and fat are likely to be discharged to sewers. Page 6.
b)
To include a section on Inverted Siphons - Standard drawings for inverted siphons to be included, but they must be designed for individually based on actual locations.
c)
Clause 2.2.4, (Structural Design Consideration for Manholes) manholes shall not be provided, for safety. Page 50.
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- Iron steps in
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Appendix A
Figure A3 : Typical Shallow Precast Concrete Manhol e (Grou nd Level to Invert of Pipe 1.2m Depth 2.5m
X I M R A T R O M T N E M E C
3 : 1 H T I W L L I F
E M A R F I . S D L I E A L T O E H D N O A M T R D E R V A D O N C A D T N S A
D E R I U O Q T E R R E S V A O C S E G L N O L I R H E P N V U A E L E M E K F C A O A M P F R O C . T U R H S T C D S T E A A C M H S E I N R O I P T F
F O S R E H Y A T I L 2 ) W . N B H T I A I L M . S W K H R D E T E T V N 0 0 I O 1 C A ( C P Y R E X I O T D S S P A R E C E L E D A R N O P U C
A 0 N I 2 M H U T L I A W H G I G N I H R F R O E B G N M I A I N R H L A C L T R C . A N O R R T E M S T T N A N C I . E M E N E R I P M C
D N U O R R U S
E T E R C N O C ) N U I T M I . S K N H I T T S 0 5 A 1 C (
G ) N G I N H A I C N R E N I E M D B U N L E E T A R E H T R G N C I E N H M 0 E O 2 C ( C
0 2 / 0 2 E D A R E S G A 0 B 0 . 4 C . N N I O M C
S U O I T I T N E M E C G . I K N H D N T I 0 L 5 B
2 1 : 1
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600 (MAX.) 350 (MAX.)
T N E M E C 3 : X 1 I M H T R I A T W L R L O I F M
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E M A R F I . D S L I E A L T O E H D N O A T M D R E R V A O D C N A D T N S A
D E R I U O Q T E R R E S V A O C S E G L N I O L R H E V P N T U A E N E M L E E K F C M A O A E C M P F O R C 3 . : X T U 1 I R H S M H T C D T R S T E I A A A H T C S W I L R E M N L I O R O I F M P T F
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A N 0 I 2 M H U T I L A W H G I G N I H R F R O E B G M N I A I N R H L A C L T A R C . N R R O T E M S T T A N N C I . E E N M R I E P M C
G ) N G I N H A I C N R E N I E M D B U N L E E T A R E H T R G N E C I N H M 0 E O 2 C ( C
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Page 100
0 2 / 0 2 E D A E R S G A 0 B 0 . 4 C . N N I O M C
D N U O R G (
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D N U O R R U S
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N I L B
S U O I T I T N E M E C . K H T 0 5
Volume 3
: S E T O N
. S R E W E S O R T E P T U E S M A R I E D W E R S E G R R O A F L G R N O O F L G 0 N 0 6 O L E 0 B 0 L 9 L D A H N S A E R P E I T P E R M A E I K D C 0 O 0 R 3 . 1
. D E T A T S E S I W R E H T O S S E L N U S R E T E M I L I M N I E R A S N O I S N E M I D . 2
T N E M E R I U Q E R D N A N O I T I D N O C L I O S E N I M R E T E D O T D E R I . U G N Q I L E I R P S R I I O S F . 3
B ) S E R T E M 5 . 2 < D < 2 . 1 E P I P A A F O N L O E I T V C E E L S T R E V N I O T L E V E L D N U O R G (
A
A Ø 6 0 0
W E I V N A L P
B
Malaysian Sewerage Industry Guidelines
Appendix A
Figure A4 : Typical Shallow Precast Concrete Manhol e with Backd ro (Groun d Level to Invert of Pipe 1.2m Depth 2.5m)
T N E M E C E M A R F I . S D I L E L A T O E H D N A O T M D R E R V A O D C N A D T N S A
D E R I U O T Q E R R E S V A O C S E G L N I O L R H E V P N E U A L E M E K F C A O A M P F R C . O T U R H S T C D S E A T A H C M S E I R O N I P T F
F O S R E H Y A ) . T I L I N 2 W M . B H T K A I L H S W T R D m E E µ V T 0 N 0 O I 1 C A ( C P Y R E X D I T O S S P A R E C E L E D A R N O P U C
3 : X I 1 M H R T I A T W L R L O I F M
R E O T F T F E R R O C O E N P C O P A U S F C R T A G U E I S N N N Y R U E L O H P P G P U A O O D T N R N R I O O T D A I N E R C A L P E S R O E H T P A N E S O L A A R C M P D
A 0 N I 2 M H U T L I A W H G I G N H I R F R O E G B N I M A N I R H L C L A T A R C . N R R O T E M S T T A I N N C . E M E N R I E P M C
D N E B . G E D 0 9 E L O
H N A M P O R D
H R S R G E E E I H R T E R W K E M O E C H A E S I I H W L G T R D O N I 0 A R H M 4 T O N A O G R C O N N O M N I I I S M T H 3 U T C G N E U R L E R O O E I N M R D 2 N E N H T E A C I H A E S R A C I N G R E N U R M M R U A C E O L H C H F A C O T
0 2 / 0 2 E D A R E S G A 0 B 0 . 4 C . N N I O C M
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2 1 : 1
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2 1 : 1
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350 (MAX.) G ) N G I N H A I C N R N I E D E M B U N E L E T A R E H T R G N C I E N H M 0 E O 2 C ( C
) N E I T M E . R K C H N T 0 O 5 C 1 ( U D T I N S U N O I T R S R A U C S
E M A R F I . D S L E I L A T O E H D N A O T M D R E R V A O D C N A D T N S A
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F O S R E H Y A T L I 2 ) . W N H I B T A I M L W . S K D H R E E T V T 0 N 0 O I ( C A 1 C P Y R E X D O T I P S S E A R C E L E D A R N O P U C
A N 0 I 2 M H U T L I A W H G I G N H I R F R O E G B N I M A N I R H L C L A T A R C . N R R O T E M S T T A I N N C . E M E N R I E C P M
D N U O R R U S
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G ) N G I I H N C A N R E N I D E M B U N E E L T A R E H T R G N C I E N H M O 0 E 2 C C (
0 2 / 0 2 E D A E R S G A 0 B 0 . 4 C . N N I O C M
Y A W / B 0 5 1 2 1 T
0 0 6 2
1 : 1
350 (MAX.)
Sewer Networks and Pump Stations
E G 3 N R A O H H C S 2 G E R E I R H R U A K E C E C H C I O R H W E T R R H E T 0 A T 4 T E R G R M O N O A E I I S M D L S U T R O R N H E L E O N W E N A E N M S N E O M A C I T G H A C H G I N C I N E U R O M M M I R U D R O O L N H C N T I F A I
S U O I T I T N E M E C G . N K I H D N T I 0 L 5 B
Volume 3
) S E R T E M 5 . 2 < ) D 0 0 < 6 2 . > 1 P E P O I R P D F K O C L A E B ( V E B - L B T N R E O I V T N C I E O S T L E V E L D N U O R G (
) S E R T E M 5 . 2 < ) 0 D 0 6 < . > 2 1 P O E P R I D P K F C O A L B E ( V A - E A L N T O R I T E V C N E I S O T L E V E L D N U O R G (
1/2Ø+100 H T I W S S T L R E O H B S G A A R W D D N E A S I N T A U V N L L A A G T . E A M I D N 2 U 1 G
S R S E T H L S O A B W G D A N R A D S E T S I U N N A L V A L T A E G M 2 N 1 U Ø G . s H o T n I 3 W
375 125
5 2 1 5 7 3
E T A L P S . M . K H T 2 1 S
: S E T O N
. S R E W E S O T R P E T U E S M R A E I D W E R S E G R R O A F L G R N O O F L G 0 0 N 6 O E L 0 B 0 L 9 L A D H N S A E R E P T I P E R M A E I K D C 0 O 0 R 3 . 1
T N E . M D E R E I T U A T Q S E E R S D I N W A R N E O H I T I T O D S N S O E C L L N I U O S S R E E N T I E M R M E I L T I M E D N I O E T R D A E S I R . N U G O I I Q N S E L I N R P E S R I M I I O D S F . . 2 3
L I A T E D E T A L P R E V O C
B
A
A
Ø 6 0 0
W E I V N A L P
B
Page 101
Appendix A
Figure A6 : Typical Medium Precast Concrete Manhole wit h backdr op (Grou nd Level to Invert of Pipe 2.5m Depth 5m)
E M A R F I . S D I L E L A T O E H D N A O T M R D E R V A D O N C A D T N S A
Y L L A N R E T N I Y D X E O T P N E I A R P A P T O L A T O R C E P F A O T S C . R E R Y T A S L A 2 C H E T R I P W
D E R I U O Q T E R R E S V A O S C G E L N I O L R H E V P N E U A L T E M E K F C N A O A E M M P F E O R C . C T U R H S 3 : X D 1 I T M S C E H R A T A H T I S A C I E M T R W N O I L R P T F L I O F M
T F R O O C P E N P C O A U S F C T R A U E G N I S N N Y R E L U N H P O O G P P I T U A O T C O D R N R E S O D A I N E R P A L P O R R O E D H A T S R E N L A A O C M P F
. N I M 0 2 H A N T I I M W U G L N A I R H G R I E H B F M O A H G R A N T C I N R C . I R L O M T L A S T N A N R E C E E M R T N E P I C
D N E B . G E D 0 9
E L O H N A
M P O R D
' A ' L I A T E D E E S
0 0 6
' A ' L I A T E D 0 2 / 0 2 E D A E R S G A 0 B 0 . 4 C . N N I O M C
Y A W / B 0 5 1 2 1 T
2 1 : I
2 1 : I
G N I D N I L B S U O I T I T N E
350 (MAX.)
G ) N G I N H A I C N R N I E D E M B U N E L E T A R E H T R G N C I E N H M 0 E O 2 C ( C
D N U O R R U S
E T E R C N O C ) N U I T M I . S K N I H T T S 0 A 5 C 1 (
E M A R F I . S D I L E L A T O E H D N A O T M R D E R V A O D C N A D T N S A
D E R I O U T Q E R R E S V A O C S G E L N O L I R H E V P N T U A E L N M E E E F C M K A O A E M P F C O R 3 . T U : X C 1 I R S M T H H C D R T S I A A T E T C A H W S I L R E M N L O R O I I F M P T F
Y L L A N R E T N I Y D X E O T P N E I A R P A P T L O T A O R C E F P A O T S C . R E R Y T A S L A 2 C H E T R I P W
. N I M 0 2 H A N T I I M W U G L N A I R H G R I E H B F M A O H G R A N T C I N R C . I R L O L M T A S T N A N E C R E E M R T N E P I C
D N U O R R U S
Sewer Networks and Pump Stations
) S E R T E M 5 ) < 0 D 0 < 6 > 5 . P 2 O E P R I D P K F C O A L B ( E V B - E B L N T O R I E T V C N E I S O T L E V E L
G ) N G I N H A I C N R E N I E M D B U N L E E T A R E H T R G N C I E N H M 0 E O 2 C ( C
375 125 5 2 1 5 7 3
E T A L P S . M . K H T 2 1
: S E T O N
T N E . S . M E R D E I R E T W A U E T Q S S E O R T R E S D E I P T N U E W A R S M E R A H N O E I D T I T I W O R D E E S S N G S O R R E O A L C L F L N I G R U O N O S S O F R E L G E N T I 0 0 N E M 6 O I M R E E L I L T B 0 0 L 9 M E L D I N D A O E T H N S A R D E R A E P E R . I T S I P E N U G O Q N I R M I L E I A S E I K N R P E S C D 0 M I R O 0 I I O R 3 D S F . . . 1 2 3
S L I A T E D E T A L P R E V O C
B
E D A R E S G A 0 B 0 . 4 C . N N I O M C
2 1 : I
1/2Ø+100
S T G U A R N D L A E T S E I N M A N V U S L G A R H E G T 2 I H S 1 W Ø S A . s T W o L D n O N 3 B A
D N U O R G (
M E C . K H T 0 5
0 2 / 0 2
E T E R C N O C ) N U I T M I . S K N I H T T S 0 5 A 1 C (
0 0 6
350 (MAX.)
E G 3 N R A O H H C S 2 G I E R E H R U R C A K E C E C H O I R H W E T R R H A 0 E T T 4 T E R G R M O N O I A E I M S D L S U T R O R H E L N E E O N W N A E N M S N E O I M A C T G H A C H G N C N I E U I R M M I O M R U D R O C O L N H N F A I T I
H T I W S S T L R E O H B S G A A R W D D N E A S I N T U A N V L L A A G T . E A M I D N 2 U 1 G
Y A W / B 0 5 1 2 1 T
E G 3 N R A O H H C S 2 G I E R E H R U R A K E C E C H C I O R H W R E T R E H A 0 T T 4 T A R G R O M N O I A E I M S D L S T U R O R H E L N E E O N W N M N A E N E O M S A C I T G H A C H G N C N I E U I M M R I O M R U D R O C O L N H N F A I T I
Volume 3
S U O I T I T N E
M E C G . I K N H D N T I 0 L 5 B
) 0 0 6 > P O R D K C A B ( A A N O I T C E S
) S E R T E M 5 < D < 5 . 2 E P I P F O L E V E L T R E V N I O T L E V E L D N U O R G (
A
A
0 6 0 Ø
W E I V N A L P
B
Page 103
Appendix A
Figure A8 : Typical Deep Precast Concrete Manhol e with Backdro p (Grou nd Level to Invert of Pipe 5m Depth 9m)
E M A R F I . D S L E I L A T O E H D N O A T M D R E R V A O D N C A D T N S A
Y L L A N R E T N I Y D X E O T P N I E A R A P T P O L T A O R C E P F A O T S C . R E R Y T A S L A 2 C H E I T R P W
D E R I U O Q T E R R E S V A O S C G E N L I O L R H E P N V E U A L T E M E N K F C E A O A M M P F E O R C . C T U R S 3 : X T H D 1 I M S C T E H R A A H T I S A C M T E I W N L R R O I L O P T F I F M
T F R O O C P E N P C O U A C F T S R G U A N E I S N N R U E Y L O N H P P O G P I T U A O T C O D E R N R S O D A I P N E R A L P O R R O E T D A H N E S R L A A O C M P F
. N I M
0 2 H A N T I I M W U G L N A I R H G R I E H B F M A O H G R A N T C I N R C . I R L O M T L T S A N A N C R E E E T M E R N P I C
' A ' L I A T E D E E S
0 0 6
D N E B . G E D
0 9 E L O H N A M P O R D
' A ' L I A T E D 0 2 / 0 2 E D A E R S G A 0 B 0 . 4 C . N N I O C M
Y A W / B 0 5 1 2 1 T
2 1 : I
G N I D
350 (MAX.)
G ) N G I I H N C A N R E N I E M D B U N E E L T A R E H T R G N C I E H N M O 0 2 E C ( C
D N U O R R U S E T E R C N O C ) N U I T M I . S K N H I T T S 0 A 5 1 C (
E M A R F I . S D I L E L A T O E H D N A O T M R D E R V A O D C N A D T N S A
D E R I U O Q T E R R E S V A O S C G E L N I O L R H E V P N E T U A L N E M E E K F C M A O A E M P F C O R 3 . T X C U : I 1 M R H S T C D H T S T E I R A H A T A W C I S L R E M N L O R O I I F M P T F
Y L L A N R E T N I Y D X E O T P N E I A R A P T P L O T A O R C E F P O A T S C . R E R Y T A S L A 2
C H E T R I P W
. N I M 0 2 H A N T I I M W U G L N A I R H G R I E H B F M A O R H G A C N I T C I R . N R L O M T L A T S N A N E C R E M E T R N E P I C
D N U O R R U S E T E R C N O C ) N U I T M I . S K N H I T T S 0 A 5 1 C (
0 2 / 0 2 E D A E R S G A 0 B 0 . 4 C . N N I O C M
Sewer Networks and Pump Stations
G ) N G I N H A I C N R N I E D E M B U N E L E T A R E H T R G N C I E N H M 0 E O 2 C ( C
) S E R T E M 9 < ) D 0 < 0 5 6 > E P P I O P R F D O K L C E A V B ( E L B - T B R E N V O I N I T C O E T S L E V E L D N U O R G (
1/2Ø+100
S G T A U N R L D A E T S E I N M A N V U S L A G R E G H T H 2 I S 1 W Ø S A . W s T o L D n O N 3 B A 375 125 5 2 1 5 7 3
E T A L P S . M . K H T 2 1
: S E T O N
T N E . S . M E R D E I R E T W A U Q T E S S E O T R E R S D E I P T U E W N A S M R N E R A I H I O E D T I T W O R E D S E S N G S O R R E C O L F A L N L I G R U O N O S S O F R E L N G E T I 0 N E M 0 6 O M I R E E L I T 0 L B 0 E M L 9 L N D A D I O E T H N S A R D E R A E E S R . P T I I P E N U G O Q N I R M I L E I A S E I K N R P E S C D 0 M I R O 0 I I O R 3 D S F . . . 1 2 3
S L I A T E D E T A L P R E V O C
B
Y A W / B 0 5 1 2 1 T
0 0 6
350 (MAX.)
E G 3 N R A O H H C S 2 G E R E I R H R U A E C K H E C C I O R H W E T R R E H T 0 A T 4 T E R G R O O M N I A I E L S S M D T O R U N R H E L E E O N W M N A E N E S N I O M A C T H G H A C G I C I N E U N R M M I O M R U D R O C O L N H N F A I T I
N I L B S U O I T I T N E M E C . K H T 0 5
H T I W S S T R L O E H B S G A A R W D D N E A S I T N U A N V L L A A G T . E A M I D N 2 U 1 G
E G 3 N R A O H H C S 2 G I E R E H R U R C A K E C E C H O I R H W E T R R H T 0 A E 4 T T A R R M G O O N I A E I S M D L S O R U T N R H E L E O N W E N A E N M E O M S N C I A T H G H A C G I N C I N E U R O M M M I R U D R O O L N H C N F A I T I
S U O I T I T N E M E C G . I K N H D N T I 0 L 5 B
Volume 3
) S E R T E M 9 < ) D 0 < 0 5 6 > E P P I O P R F D O K L C E A V B ( E L A - T A R E N V O I N I T O C T E S L E V E L D N U O R G (
A
A
0 0 Ø 6
W E I V N A L P
B
Page 105
Appendix A
Figure A10 : Typical Induc t Vent Detail
Induct Vent
Centreline of manhole
150 Min.
750 Min.
Inside face of Manhole
150 Min.
Column Support
Notes : 1. All dimmensions are in millimetres. 2. Diameter of induct vent shall be approximately 1/2 of the forcemain but shall not exceed 300mm. Sewer Networks and Pump Stations
Volume 3
Page 107
Appendix A
Figure A13 : Typical Details of Invert ed Siphons o r Depressed Sewer
C
N O I T A V T E E L L E N I T 0 R 5 E 7 V F N O I
Ø 0 5 7
Ø 0 5 7
400
D
D
R E B M A H C T E L T U O F O N A L P
Ø 0 5 3
D D N O I T C E S
G E D I L S
R E B M A H C T E L T U O Ø 0 0 5
250
C C N O I T C E S
) L A C I P Y T ( E D I U G E T A
: S E T O N
D E T A T S E S N I O W I T R A E L H L R T A S E O T R G S S E R N S I A W E E L E L L S R N O U O R H O F S N F G R A E G N M T N O E Y O L F M I L 0 I T L 0 0 I S 0 9 M 6 D U J N E N I B A O E T L R R L E S N A A T R H E E O S G S S M W R N N I I O A E E L E I I P D S P S I P 0 R D P N E T E E R 0 I T F U I M E 3 E I O O K L H D C T M A T A U I L O P I L R U D Q W A . . . 3 1 2
232 375
Ø 0 0 5
Ø 0 5 3
Ø 0 0 4
C
A
Ø 0 0 5
Ø 0 5 3
Ø 0 0 4 Ø 0 0 5
R E B M A H C T E L N I
B
B
N O I T A V T E E L L E N I T 0 R 5 E 7 V F N O I
Ø 0 5 3
232 125
R E B M A H C T E L N I F O N A L P
0 0 0 2
) L A C I P Y T ( E D I U G E T A G E D I L S
A A N O I T C E S
B B N O I T C E S
375
Ø 0 5 7
Ø 0 5 7
A
Page 110
Volume 3
Malaysian Sewerage Industry Guidelines
Appendix A
Figure A14 : Typical Details of Receivin g Manhole, Force Main and Washou t Valve E P I P R E W E S Ø 0 0 3 E S E S R I S E S U R O W C R U E O E H L T C G O 4 N I S O S S S ( L E E L L H A N T U Y W K D B C E D I S E R U I F B I ) . Y E C X A B E A L O P C T S M
R E V N O O C D N E O D R D I E E B L I E T M ) C A R U R A T D F ( R Y E O T M U M D A T R N Y F V E A D M E N E H A C
E P I P
T E K C
O R
F O R E Y A L 2
E L R G E N B A M ° A 5 H 4 C
R O E T B T M C A U H D C T T N N E E V V 3 : 1 R A T R O M T N E M E C
H T I W L L I F
7 A C R B
S R C E R Y N T A O S L Y A 2 X C H O E T P R I E P W Y B R E T A A D U L T I D S L S A R Y R O V E C E A V D E O F N H C O U
G N I N I L A N I M U L A . K H T 2 1
G A N N I I R M D 2 : U N 1 E L D A 1 E N A S P E H & O R I G T L . K H N S E H 2 : M H T 1 T 0 N E I 2 I C W
H T U
O M L L E B
R E B M A H 0 C 2 U E T D I A S R N I G T E S S A A C B
2 H C T R I W U 0 T 2 I S E 8 N I D A T A C S R R A G B C E F . L O K O H R T H E 5 N Y 2 A A 2 M L
E L O H N A M G N I V I E C E R F O L I A T E D
E L A C S O T T O N
Ø 0 0 2
P O O S S J L E V E L D N U O R G
R O T P A D A E G N A L F
E V L A V R U O C S
R C N O C . K H T 0 5 1
T S A C E R P D R G N A I D R N E A T T E S R 0 C 0 2 N 1 O Ø C
E V L A V T U O H S A W 0 5 1 Ø
S S E L N U S E R T E M I L L I M N I E R . A D S E N T A O I T S S N E E S M I I W D R L L E H A T . 3 O
L L A F T U O E L B A T I U S R O N I A R D O T
. Y X L L A U M F 0 E 2 R E A D E T C T A . C G K A E H P R T M G 0 0 O G 1 C A
E D A R
H T I D N . W S A . D E Y D M C H N E A E T A L R K I Y B H W L T D L A B I D K A E N A E W N E E T R N E R E T I B F E A T F L P N N I P U T D I . S M N T N K T O A I H N C A T A R P A 2 L E 1 P M E S Y L x G U L 0 R A R G O A 0 F N N 0 E N 1 U L I I R x Q K M 0 E U E T 0 E E C I O T X 0 H T 1 C S L B E
E D A R G E T E R C N O C . K E H S T A 0 B 0 0 3 2
0 5 Ø . S S E O L N O 3 H
G E T E R C N T O R C O . K P H P T U 0 S 0 0 3 2
E V L A V T U O H S A W F L E O A C N S O O T I T T O A N L L A T S N I F O L I A T E D
T S K U C R O H L T B
A
G N I L P U
G N I L P U O C E L B I X E L F
O C E L B I X E L F E V ) O Y B E A R N G I A D M E T E I N C A R P O E F ( B N I O A T M D E N C U R O O R F G
D N E B ° 5 4
E V ) O Y B E A R N G I A D E M T E I N C A R P O F E ( B N O I A T M D E N C U R O O R F G
D N U O R R U S E T E
0 5 1 Ø
N A L P
K C O L B R T O I H U C S N O A T
S E S B E L L C A C A H S N S O R I T E I S W O E P S E F L O O E H N N I A L . E M R E T F T I O N S N N E O C O I D T D E A N N T A I N S M E I R R E R E V T O O . E 2 C D
. C N O C N A E L 7 . K E H D T A 0 R 5 G
. I . D
T T E O K T G C I N I
A
S T N I . R O J A S T T R N O E M N T O P N E M M O E C C E 3 : L 1 O H H T N I A W M D T E S L A L I C F E E : R B S P L L L E L T A A O . H N 1 S
N A L P
' A ` L I A T E D
E V L A V R I A
E C I U L S
S T N I O J
O R P P A
E G N A L F
K C O L B R T O I H U C S N O A T
Sewer Networks and Pump Stations
T R E V L U C R E V O G N N I S L E O S I A T O C S A R O V C T T E O L N N E I A M E C R O F L A C I P Y T
D N E B ° 5 4
E V L A V
E E T D E V S T N I O J E G N A L F
K C O L B R T O I H U C S N O A T
T I U S
E V L A V R I A 0 5 Ø
E V L A V E C I U L S 0 5 Ø
O T E C E I P N O I S N E T X E . I . D 0 5 Ø
D E G E . N I . E A T D L O F E T N H T D O E E F D O L T A D E L N W P E
N O I T A L L A T S N I ) D E ' V N U L E A ` L O A A L V R C S I O A R G T T I E T E A V O D E O N G B A A ( W E S L A C I P Y T
K C O L B R T O I H U C S N O A T
Volume 3
Page 111
Appendix A
Figure A15 : Precast Concrete Chamber (Type A ) and Details of Air Valve and Scour Valve Chamber
0 0 3
5 2 2
0 5 1
5 7
0 0 9
150
150
5 7
5 2 2
0 5 1 75MIN.
225
50
50
900
380
150
225
50
50 150
380
150
0 5 1 0 5 0 5
0 3 4 0 3 4
0 5 1
0 5 0 5
900(NTS)
0 3 6
0 5 2
430
580
75
Page 112
Volume 3
Malaysian Sewerage Industry Guidelines
Appendix A
Figure A16 : Standard Pipe Beddi ngs LOADFACTOR2.8
LOADFACTOR1.9 100 MIN.
150
GRADE20/20 CONCRETEBACKFI LL
0.50O.D. 0.25O.D. WITH100 MIN. 150
300MIN
SELECTED COMPACTED BACKFILL
SEWERPIPE
SEWERPIPE
20AGGREGATE
20AGGREGATE
0 0 3 + D . O
0.50D 0.25O.D. WITH100 MIN.
SEWERPIPE
0.25O.D. WITH100MIN. O.D+300
0.D+300
O.D+300
CRUSHED RUN BEDDING FACTOR 1.9
CONCRETE ARCH BEDDING FACTOR 2.8
CONCRETE SURROUND BEDDING FACTOR 3.0
PIPEEMBEDDEDIN CAREFULLYCOMPACTED20DIA. AGGREGATE EXTENDINGHALFWAYUPTO SIDEOF THEPIPE. THEREMAINDER SIDEFILL ANDTOPCOMPACTEDCAREFULLYWITHBACKFILL.
PIPEEMBEDDEDINCAREFULLYCOMPACTED20 DIA. AGGREGATE EXTENDINGHALFWAYUP TOSIDES OFTHEPIPE. THEREMAINDER SIDETO FILLAND TOPWITH MONOLITHICPLAINCONCRETE
GRADE20/20CONCRETE SURROUND150 MIN
(FORSEWERSWITHLESSTHAN 1MCOVER, FORCEMAINSANDINVERTEDSYPHON.)
THESELECTEDCOMPACTBACKFILLFORVITRIFIEDCLAYPIPESHALLBE COMPACTEDDRYSOIL (FREEFROMVEGETABLEORGANICMATTERS& EXCAVATION/COMPACTED DRYRED EARTH/SAND/CHIPPING/STONES NOT GREATERTHAN25.
DETECTABLE MARKERTAPE
GROUNDLEVEL
BACKFILL&COMPACTWITH SUITABLESOILTO REQUIREDLEVEL LOADFACTOR1.9
FINALBACKFILL (SELECTEDBACKFILL)
BACKFILLWITHWELLCOMPACTEDSOIL (HANDHELDCOMPACTOR)
VARIES
300MIN
COMPACTEDSELECTED BACKFILLMATERIAL
BACKFILLWITHSAND (HANDHELDCOMPACTOR)
SEWERPIPE
300mmMIN.
0.25O.D.
GRADE20/20CONCRETE
INITIAL BACKFILL
0.25O.D. WITH100 MIN. 0.D+300
SEWERPIPE
32mmØ
2
CONCRETEGRADE25 N/mm ONELAYEROF A8(BRC) 150THICK SAND
SPRINGLINE
PIPE EMBEDMENT (CRUSHERRUN) HAUNCHING
CONCRETE CRADLE BEDDING
SEWERPIPE 150to300mm(20mmØ)
CRUSHER RUN BEDDING FOR FLEXIBLE PIPES
"X' NO. OF70 ØBAKAUPILE (REFERTABLE`A') 70Ø BAKAUPILEAT300C/CALONGPIPEBAKAU PILESSHALLBE DRIVENTOSET OR10mDEPTH (2 x5m LONG) WHICHEVERACHIEVEDFIRST
SEWER PIPE LAYING ON UNSUITABLE SOIL
NOTES: 1. THEBACKFILL MATERIALSHALLBE PLACEDOVERTHEFULL WIDTHOFTHE TRENCHANDWELLCOMPACTEDIN LAYERS NOTEXCEEDING300. 2.INCREASEDIN BAKAUPILESLENGTHANDNUMBER. 3. SI ISREQUIREDTO DETERMINESOIL CONDITIONANDREQUIREMENT FORPILING.
PIPE SIZE
MAXIMUM TRENCH WIDTH
TABLE 2
TABLE 1 MAXIMUM TRENCH WIDTH TABLE `A'
NOTE: FOR FILLINGOF TRENCHESALONG/ACROSS CARRIAGEWAY, BACKFILL MATERIALSHALL USESANDFROMAN APPROVEDSOURCE.
Sewer Networks and Pump Stations
Volume 3
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Appendix A
Figure A. 17 Vacuum sewage col lectio n syst em
Figure A. 18 House connecti on
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Appendix A
Figure A. 19 (a) Example of vacuum statio n wit h hous ed collecti on vessel
Sewer Networks and Pump Stations
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Appendix A
Figure A. 19 (b) Example of vacuum s tation w ith h oused col lectio n vessel
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Appendix A
Figure A. 20 (a) Collectio n chambers wi th in terface valves vented thr ough breather pipes
Figure A. 20 (b) Coll ection c hamber wit h int erface valve activated by fl oat
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Appendix A
Figure A. 20 (c) Mult i-valve coll ection chamber
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Appendix A
Figure A. 21 Vacuum sewer prof iles (not t o scale)
Figure A. 22 Example of vacuum sewer profiles for uphill and downhill transport (not t o scale)
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Appendix A
Figure A. 23 Y-branch for vacuum s ewer
Figure A. 24 Method of j oining crossover pip es and branch sewers to vacuum mains
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Appendix A
Figure A. 25 Typical details of dry-well pump station OVERFLOW PIPE DISCHARGE TO MONSOON DRAIN
OVERFLOW CHAMBER
DRAIN
RAMP DOWN
CONC. APRON LAID TO FALL
3 LAYER CONC. VENTILATION BLOCK AT TOP AND BOTTOM LEVEL
LIQUID RETURN FROM OTHER UNIT PROCESSES
WP
FORCEMAIN MECHANICAL COARSE SCREEN
A A GATE VALVE.
13 14 15 16 17 18 19 20 21 22 23
INCOMING SEWER G.I CHAIN GUARD PENSTOCK GRATING COVER
AIR EXTRACTOR FAN
. D R A U G N I A H DN C I 13 12 11 10 9 8 7 6 5 4 3 2 1 . G 14 15 16 1718 19 20 21
R.C STAIRCASE TO ENGR'S DETAIL
3 LAYER CONC. VENTILATION BLOCK AT TOP AND BOTTOM LEVEL
CHECK VALVE.
CONC. THRUST BLOCK.
12 11 10 9 8 7 6 5 4 3 2 1
CONC. THRUST BLOCK.
EXTRACTOR FAN R.C STAIRCASE TO ENGR'S DETAIL.
CONCRETE VENTILATION BLOCK AT TOP AND BOTTOM LEVEL
DN
CHAIN GUARD.
ADJUSTABLE GLASS LOUVRES WINDOW
SPOT LIGHT CHEQUER PLATE DOOR
BRICKWALL C/W CEMENT PLASTER ON BOTH SIDES DRY PIT PUMPS
PLAN VIEW
COPPER TYPE LIGHTNING ARRESTOR
LIFTING I-BEAM C/W CARRIER
R.C GUTTER TO ENGR'S DETAIL
RAIN WATER DOWN PIPE TO NEAREST SUMP
MECHANICAL COARSE SCREEN
DOOR
SCREENINGS COLLECTION BIN
BRICKWALL C/W CEMENT PLASTER ON BOTH SIDES
PENSTOCK
WINDOW HANDRAIL
CHEQUER PLATE
3 LAYER CONC. VENTILATION BLOCK
HANDRAIL R.C STAIRCASE TO ENGR'S DETAIL
WET WELL
DRY WELL
PERFORATED SLAB CAT LADDER OPENINGS
CHECK VALVE INCOMING SEWER GATE VALVE
(FLOAT SWITCH)
2nd. STANDBY PUMP START 2nd. DUTY PUMP START
ALARM 1st. STANDBY PUMP START
1st.. DUTY PUMP START ALL PUMPSTOP
STOP LOG SUMP BWL
N.B. : The discharge level for dewatering pump shall be higher than the invert level of overflow pipe to prevent sewage from back flowing into the dry well during flooding
DEWATERING PUMP
DRY PIT PUMPS
SECTION VIEW
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Appendix A
Figure A. 26 Typic al detail of w et-well pump st ation
MECH. COARSE SCREEN INCOMING SEWER STEPS GRATING COVER
OVERFLOW PIPE DISCHARGE TO DRAIN
V.C.P STAND PIPE CONC. APRON
COLLECTION BIN CLEAR SPACING S.STEEL MANUAL FINE SCREEN
OVERFLOW CHAMBER
INFLUENT PUMP
A GRATING COVER
PRIMARY SCREEN 17 18 19 20 21 22 23
A
PUMP SUMP S.STEEL HANDRAIL
STEPS
EXPLOSION PROOF SPOT LIGHT CHECK VALVE FLEXIBLE COUPLING GATE VALVE
PENSTOCK
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2
1 DELIVERY PIPE
R.C STAIRCASE TO ENGR'S DETAIL
PLAN VIEW LIFTING I-BEAM C/W CARRIER MECH. COARSE SCREEN HANDRAIL CLEAR SPACING MANUAL FINE SCREEN
CHAIN GUARD CHECK VALVE FLEXIBLE COUPLING GATE VALVE DELIVERY PIPE
PENSTOCK
OVERFLOW PIPE DISCHARGE TO DRAIN
NON-EXPLOSION SPOT LIGHT
DELIVERY PIPE GUIDERAIL
OVERFLOW CHAMBER
S.S PERFORATED TROUGH
PUMP SUMP
LIFTING CHAIN
PRIMARY SCREEN CHAMBER CONC. SLAB R.C WALL TO ENGR'S DETAIL
IL
1 : 2
IL
FRP STOP LOG C/W HAND WHEEL IL
OPENING ALARM START
MANUAL COARSE SCREEN STOP
SECTION A-A
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Appendix A
Figure A. 27 Buffer Zone for Pump Station wit h Super Stru ctu re
Typical Section
1. 20m buffer zone shall be provided from the external edge of the P.S super-structure fence/boundary to the nearest habitable building fence/boundary as required by building by-laws. The buffer zone shall be sufficient to allow for pump station access and working area . 2. Non-Habitable buildings may be located within buffer zone. 3. Where the pump station is located in sensitive areas, additional buffer zone may be specified for the purpose of beutification.
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Appendix A
Figure A. 28 Buffer Zone for Pump without Super Structure
Vent Vent
H Properties Fence
P.S Fence
P.S Fence
Properties Fence
G
20m i Buffer
5m
5m Access and Beutifician
Access and Beutificatio
20m Buffer
Sectional Plan
Note 1.
20m Buff er zone shall be provided f rom the perimeter (f ence/boundary ) of the pump station to t he nearest habitable building fenc e/boundary as required by building by-laws. The buffer zone shall be sufficient to allow f or pump station access and working area.
2. Non-habitable buildings may be located within the buff er zone but shall not obstruct operation, maintenance and access. 3. H is the height of t he v ent pipe which shall be at least higher than roof eaves lev el for buildings up to 2 storey s high. The vent cowl shall be at least 20m away f orm the nearest building window. 4. Where the pump station is located in sensit iv e areas, additional buff er zone may be specif ied f or the purpose beutification.
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Appendix A
Figure A. 29 Buffer Zone for Pump witho ut Super Structure
Symbols
PIPE
BUILDING (WOODEN OR
DN 375 R.C.P
DN 375 R.C.P
1:80 BUILDING
1:72
PROP OSED MANHOLE AN D SEWER IN PLAN
DIRECTION OF SEW ER
GATE POND
PON
PROP OSED MANHOLE AND SEWER IN PROFILE
FIRE
H
PAVED RAIL CULVER
EXISTING MANHOLE AND SEWER IN PLAN
BRIDGE PAVE D CHANNEL AND FLOW EXISTING MANHOLE AND SEWER IN PROFILE
UNPAVED SIDE CHAINLINK UTILITY
GAS
G
TELEPHONE ELECTRIC
W
STREET
E
ELECTRICAL TRANSMISSION LINE OR CONDUIT (GENERALLY 1m DEEP)
T
TELEPHONE CONDUIT (GENERALLY 1.5m DEEP)
LIGHTSIDE POLE SIDE
PROPERTY, LOT OR RESERVE
PROV ISION FOR BACKDROP FOR SEWER CONNECTION
SEPTIC ST
WATER MAIN (GENERALLY 1m DEEP)
PROV ISION FOR T-JOINT FOR SEWER CONNECTION
BOREHOL
Abbrev iat io ns A.C.P. C.I. CH. CL. CONC. CRS D.I. DIA.(ø) D.M.H. DN. DRG. EXIST. GD. GR. H.A. HORZ I.D. INV. JLN. KG. LRG. LT MAX. M.H. MIN. MOD. NO.
ASBESTOS CEMENT CAST CHAINAG CLASS CONCRET CENTRE DUCTILE DIAMETE DROP NOMINAL DRAWIN EXISTIN GROUND GRADE HIGH HORIZONTA INSIDE INVER JALAN KAMPUN LORON LEFT MAXIMU MANHOL MINIMU MODIFIE NUMBE
Sewer Networks and Pump Stations
N.T.S. O.D. R.C. R.C.P RET. RT S SG. SHT. SPEC STD. SCW. STL. STA. TYP. VAR. VERT. V.C.P HDPE
Volume 3
NOT TO OUTSIDE REINFORCED REINFORCED CONCRETE RETICULATION RIGHT SLOPE STREAM OR SHEET SPECIFICATIO STANDAR STANDARD CUT-OUT STEEL STATIO TYPICA VARIE VERTICA VITRIFIED CLAY HIGH DENSITY
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APPENDIX B
Appendix B
Table B1
Classes of Rigid Pipe Required for Various Depth
H T P E D S U O I R A V R O F 1 . B D E E R L I B U A Q T E R E P I P D I G I R F O S E S S A L C
E P I P Y A L C
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Appendix B
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APPENDIX C
Appendix C
Ap pen di x C 1
Report fo rmat fo r CCTV In sp ect ion
Contractor :
Project-Information Project Name :
Client Contact Position Road Town State Telephone Fax Mobile E- Mail
:
Site Contact Position Road Town State Telephone Fax Mobile E-Mail
:
Contractor Contact Position Road Town State Telephone Fax Mobile E-Mail
:
Project Number :
Contact :
Date :
: : : : : : : : :
: : : : : : : : :
: : : : : : : : :
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Appendix C
Ap pen di x C 2
Report f or mat for CCTV Inspec ti on
Contractor :
Inspection Report Date:
Job nr:
Weather
Operator
Section Number
PLR:
Present:
Vehicle:
Camera:
Preset:
Cleaned:
Grade:
Road:
Division:
Start MH:
Place:
District:
End MH:
Location:
Tape No.:
Total Length:
Purpose:
Size/Shape:
Use:
Material:
Catchment:
Lining: Category:
Comment: Location details: Slope
Position Code
Observation
Counter
Photo
Grade
MH No.
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Appendix C
Ap pen di x C 3
Report fo rmat fo r CCTV In sp ect ion
Contractor :
Inspection Photos Town :
Road :
Sewer Networks and Pump Stations
Date :
Volume 3
Section Nmber :
PLR :
Page 131
Appendix C
Ap pen di x C 4
Report f or mat for CCTV Inspec ti on
DEFECT SUMMARY OF PIPE SECTIONS INSPECTION From MH :
Item Start MH
To MH :
End MH
Pipe Dia. (mm)
Material
Pipe
Infiltration
Wide Cracks or
Length (M) Seeping Dripping Running Joints Fractures
Others
Section
Comments
Total
N.B : When more than one defect is recorded at the same chainage, the most severe defect is counted. Prepared By : ( Name : Qualified Person & Company) Date Of Report :
132
Approved By : ( Qualified Person )
Prepared By : ( Name : Qualified Person & Company) Date Of Report :
Date
Volume 3
:
Malaysian Sewerage Industry Guidelines
Appendix C
Ap pen di x C 5
Repor Repo r t fo r mat fo r CCTV In sp ect i on
DEFECT SUMMARY OF PIPE SECTIONS INSPECTION
Fr o m MH :
Item No.
Start MH
To MH :
Finish MH
Position (M)
Sewer Networks and Pump Stations
Code
Description
Volume 3
Grade
Page 133
Appendix C
Ap pendi pen di x C 6
Mod ul es
Section 5 - Structural Defect Coding (Module 6A) C CL CC CM CS
CR AC ACK Longitudinal Circumferential Multiple Spiral
5.1 5.2 5. 2 5.2 5.2
F FL FC FM FS
FRAC FRACTU TURE RE Longitudinal Circumferential Multiple Spiral
5.7 5.7 5.7 5. 7 5.7
S
SURF SURFAC ACE E DAMAGE Roughn Roughness ess Increased Mechanical Chemical At Attack Not Evident
5.30
S
5.30
5.30
SAV SAVM SAVC SAVZ
SURF SURFAC ACE E DAMAGE Aggregate Aggregate Visible Visible Mechanical Chemical Attack Not Ev Evident
SRI SRIM SRIC SRIZ S SMV SMWM SMWC SMWZ
RP RPR RPRD RPP SMWZ
134
SURF SURFAC ACE E DAMAGE Missing Wall Me Mechanical Chemical Attack No Not Evident
5.31 5.31 5.32 5.30
S
5.31 5.31 5.31 5.32
SSS SSSM SSSC SSSZ
POINT POINT REPAIR REPAIR
5.62
Pipe Replaced Replaced Defective Patch Repair Not Evident
5.62 5. 62 5.62 5.32
SURF SURFAC ACE E DAMAGE Surface Surface Spalling Spalling Mechanical Chemical Attack Not Evident
5.30 5 . 31 5. 3 1 5 . 32
B BROK BROKEN EN BSV Soil Visible Beyond Defect BVV old Visible Beyond Defect S SAP SAPM SAPC SAPZ
5.30
S
5.31 5 . 31 5. 3 1 5 . 32
SZ SZM SZC SZZ
SURF SURFAC ACE E DAMAGE Aggregate Aggregate Projecting Me M echanical Chemical At Attack No N ot Evident SURF SURFAC ACE E DAMAGE Other Other Mechanical Chemical Attack Not Evident
5.14 5. 1 4 5. 14
5.30 5.30 5.31 5.31 5.32 5.30 5.31 5. 31 5.31 5 . 32
H H OL OL E HSV Soil Visible Beyond Defect HSV old Visible Beyond Defect S
SURF SURFAC ACE E DAMAGE SAM Aggregate Aggregate Missing SAMM Me Mechanical SAMC Chemical At Attack SAMZ No Not Evident S
SURF SURFAC ACE E DAMAGE
SCP Corrosion (metal pipe)
5.16 5.16 5.16
5.30 5.30 5.31 5 . 31 5.32 5.30
5.31 5.31
D DEFORM DEFORMED ED DV Deformed Vertically (brick) DH Deformed Horizontally (brick)
5.18 5.18
S
SURF SURFAC ACE E DAMAGE SRV Reinforcement Reinforcement Visible SRVM Me M echanical SRVC Chemical At Attack SRVZ No Not Evident
5.18
XP Pipe Collapse XB Brick Collapse
5.22 5.22
J J OI OIN T JO Joint Offset (Displaced) JS Joint Separated (Open) JA Joint Angular
5.25 5.25 5.25 5.25
5.30
S
5.30
S
5.30
5.30 5.31 5.31 5.32
X
COLL COLLAP APSE SE
SURF SURFAC ACE E DAMAGE SRP Reinforcement Reinforcement Projecting SRPM Me M echanical SRPC Chemical At Attack SRPZ No Not Evident
LF
LINING LINING FAILURE FAILURE
5.44
LF
LFD LFDE LFB LFCS LFAC
Detached Lining Defective End Blistered Lining Service Cut Shifted Abandoned Connection
5 .4 4 5 .4 4 5.44 5.44 5. 4 4
LFOC LFUC LFBK LFW
LINING LINING FAILURE FAILURE (continue) Ov Overcut Service Undercut Service Buokled Lining Wrinkled Lining
LFZ Other
5.22
SURFACE SURFACE DAMAGE DAMAGE
5.30
SAP Aggregate Projecting Projecting
5.30
5.31 5.31 5.32
SAPM M echanical SAPC Chemical At Attack SAPZ No N ot Evident
5.31 5.31 5. 3 2
5.44
WF WELD FAILURE FAILURE
5.56
5.44 5.44 5.44 5.44
WFL WFG WFM WFS
5.56 5.56 5.56 5.56
5 . 44
WFZ Un U nidentified
Longitudinal Circumferental Multiple Sp Spiral
5.56
RP POINT POINT REPAIR REPAIR 5.62 (continues) RPL Localized Localized Pipeliner Pipeliner 5.62 RPLD Defective 5.62 RPZ Other 5 . 62
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Appendix C
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Malaysian Sewerage Industry Guidelines
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