Guide to Piping Engineering

5.0 Piping

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5.1

INTRODUCTION TO PIPING ENGINEERING Piping is a major contributory in the Design and Construction of ™ Refinery, ™ Petrochemical, ™ Oil & gas plants

5.2

BASICS OF PIPING PIPING: Piping is system of pipes which along with the inline components such as flanges, valves, fittings, bolts, gaskets and supports used to convey the fluids from one location to another. PIPE SIZE: Pipes are usually specified by the standard pipe size designations such as Nominal Pipe size and wall thickness. Nominal pipe size (NPS): It is dimensional designator of pipe size. It indicates standard pipe size when followed by the specific size designation number without an inch symbol. Diameter nominal (DN): is also a dimensionless designator of pipe size in the metric unit system, developed by the International Standards Organization (ISO). It indicates standard pipe size when followed by the specific size designation number without a millimeter symbol. Pipe wall thickness (Schedule) is expressed in numbers. A schedule number indicates the approximate value of the expression 1000 P/S, where P is the service pressure and S is the allowable stress, both expressed in pounds per square inch (psi). The higher the schedule number, the thicker the pipe. The outside diameter of each pipe size is standardized. Therefore, a particular nominal pipe size will have a different inside diameter depending upon the schedule number specified.

Schedule

Weight series

Carbon steel(ANSI B16.10)

5,10,20,30,40,60,80,100,120,160

Stainless steel(ANSI B16.19)

5S, 10S, 20S, 30S, 40S, 60S, 80S

Std

Standard

XS

Extra strong

XXS

Extra Extra Strong

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5.2.1

PIPING CLASSIFICATION It is usual industry practice to classify the pipe in accordance with the pressure temperature rating system used for classifying flanges. However, it is not essential that piping be classified as Class 150, 300, 400, 600, 900, 1500, and 2500. The piping rating must be governed by the pressure temperature rating of the weakest pressure containing item in the piping. The weakest item in a piping system may be a fitting made of weaker material or rated lower due to design and other considerations. Piping Class Ratings Based on ASME B16.5 and Corresponding PN

In addition, the piping may be classified by class ratings covered by other ASME standards, such as ASME B16.1, B16.3, B16.24, and B16.42. A piping system may be rated for a unique set of pressures and temperatures not covered by any standard. Nominal Pressure (PN) is the rating designator followed by a designation number, which indicates the approximate pressure rating in bars. The bar is the unit of pressure, and 1 bar is equal to 14.732 psi or 100 kilopascals (kPa). 5.2.2

PIPING MATERIALS: Piping material selection is mainly based on their strength to withstand stress, corrosion resistance, weldability, etc. Broad classifications of the piping materials are metallic, non-metallic and lined.

Sl. No.

Material

Tolerable Temperature range

1

Carbon Steel

-29 0C to 427 0C

2

Alloy Steel

-29 0C to 600 0C

Service Non corrosive fluid services where impurities are accepted Non corrosive fluid services where impurities are accepted

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Stainless 3

Corrosive fluid services -29 0C to 800 0C

Steel/

where impurities are not

Duplex SS

accepted

Low 4

Non corrosive & low temp

Temperature

5

-48 0C to 400 0C

fluid services where impurities

carbon Steel

are accepted.

Galvanized

Drinking water, instrument air

steel

& nitrogen (LP)

6

PVC

7

GRP

For Acidic Fluid Service

Max 600 C

Conditions. Corrosive fluid / Water

Selection of the material based on temperature and pressure shall comply with some codes and standards. 5.2.3

PIPE FITTINGS: Fittings are used in pipe systems to connect straight pipe sections to adapt to different sizes or shapes to regulate the flow of fluid. Different types of pipe fittings used are:

Cap

Tee

Reducer

Coupling

Olets

Elbow

Cross

Different types

fittings

reducer

elbow

olets

tee

concentric

900

weldolet

Reducer tee

eccentric

450

sockolet

Olets are used when there is a sudden reduction in the pipe size from large bore to small bore in case of instrument tapping. The above fittings are connected to the pipe by the following methods:

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Y-Bend

Butt welding

Socket welding

Threaded/Seal weld

Flanges

Spectacle Blind/Spacer & Blind This is used in between two flanges to completely stop or allow the flow of the fluid in the pipeline.In a process plant, blanks are usually required to isolate individual pieces of equipment at shutdown and to positively block off selected process lines at the process unit limits. They are also needed during operation wherever positive shutoff is required to prevent leakage of one fluid into another. Blanks, especially for larger size flanges, are typically provided with a companion spacer which has a full-size opening consistent with the inside bore diameter of the flange. ™ In the piping or at the nozzle of all process and utility connections to vessels where necessary to provide safe entry for inspection and maintenance personnel ™ In the suction and discharge lines of all turbines and compressors, except atmospheric suction of air fans ™ At the inlets and outlets of process piping to fired heaters ™ All fuel and pilot gas headers to each fired heater ™ Spared equipment capable of being bypassed for maintenance ™ Safety valve bypass lines ™ Process battery limits

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™ Blanks should be made from a plate or forging specification, approved for use by ASME B31.3, of essentially the same chemical composition as the mating flanges and piping involved. Pipe Fittings & Connections ™ Butt welded connections shall normally be used for all alloy/carbon steel piping of 2” & larger. ™ Alloy/carbon steel piping of 1.5” NB and below shall be socket welded. ™ Threaded connections shall be avoided except in galvanized piping. ™ Flanged joints shall be minimized as it is a point of potential leakage. Flanges are used when the joints need dismantling. It may be used to connect piping to equipment or valves, to connect pipe lines of dissimilar materials, where spool pieces are required to permit removal or servicing of equipments and where pipes and fittings are with flanged ends. Notes: ™ All pipe lines carrying toxic/inflammable fluids shall be seamless. ™ Utility piping can be ERW or seam welded. ™ Steam pipe lines shall be preferably seamless. Hose & Hose couplings

Where temporary connections are required, there this type of fitting is provided

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5.2.4

VALVES: Valves are used in the pipe lines to regulate the flow of fluids. Different types of valves are used to meet the flow requirement CLASSIFICATION OF VALVES

1. Based on functions

Isolation

Gate Valve

Regulation

Non-Return

Globe Valve

Special Purpose

Multi-port Valve Check Valve

Ball Valve

Needle Valve

Plug Valve

Butterfly Valve

Piston Valve

Diaphragm Valve

Flush Bottom Valves

Float valves

Foot Valves

Line Blind valves Diaphragm Valve

Piston Valve

Pinch Valve

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Based on operation

Based on End Connection

Self Operated Valves

Check Valves

Screwed Ends Flanged Ends Butt Weld Ends

Wafer Type

Buttress Ends

Butterfly valve: these have quick opening and closing, quarter turn mechanism to control the flow of fluid through the pipe line.

Gate valve: is a valve that opens by lifting a round or rectangular gate/ wedge out of the path of the fluid. These are commonly used to close or open the valve completely, sometimes may be used to regulate the flow

Globe valve: Globe valves are spherical in shape. The two halves of the valve body are separated by an internal baffle which has an opening forming a seat onto which a movable disc can be screwed in to close (or shut) the valve. In globe valves, the disc is connected to a stem which is operated by screw action. Globe valves are used for applications requiring throttling and frequent operation.

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Ball valve: These are used for tight shutoff operations. A ball valve (like the butterfly valve, is one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked. Cannot be used for regulating/ throttling applications. Check valves: Check valves, also referred to as "non-return" or "one-way directional" valves, are very simple valves that allow fluid, air or gas to flow in only one direction. When the fluid moves in the pre-determined direction, the valve opens. Any backflow is prevented by the moveable portion of the valve. Solenoid Valves: Solenoid valves are electrically operated devices that control the flow of liquids. Solenoid valves are electromechanical devices that use a wire coil and a movable plunger, called a solenoid, to control a particular valve. The solenoid controls the valve during either the open or closed positions. Thus, these kinds of valves do not regulate flow. They are used for the remote control of valves for directional control of liquids. 5.2.5

PIPE STRESS ANALYSIS: Piping Stress analysis addresses to the static and dynamic loading calculations which result from the effect of gravity, temperature changes, internal and external pressures, change in the fluid flow rate, and seismic activity. One way to reduce stress in pipe lines is by making them more flexible to stress which otherwise results in the failure of the pipe, leakage at the joints/flanges or detrimental distortion of connected equipments. We accomplish this by performing Stress Analysis of critical sections (i.e., critical lines) of the piping system. Stress Engineer identifies the Critical Lines based on the changes in the operating conditions such as temperature, pressure and vibrations in the piping system. Stress of a material is defined as the internal resistance per unit area to the deformation caused by the unit load. Different types of stresses that occur in the piping system are:

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Primary stresses

1

Bending

nature

nature

pipe, piping components, internal pressure, Occasional loads like wind, seismic load

Local Stresses

Stresses

Direct shear and bending in

Caused due to dead weight of 2

Secondary

in

Caused due to thermal expansion

Localized bending and shear in nature

Caused due to local load like load of welded lug on pipe

Pipes can be made flexible to thermal expansion by providing them with expansion loops/expansion joints or bellows. Another way is to give supports at appropriate points to avoid failure by bending/sagging. The purpose of the pipe stress analysis is to ensure the: ™ Safety of the piping and piping components. ™ Safety of the connected equipment and supporting structure ™ and also to ensure that the piping deflections are within the limit STRESS ANALYSIS I/O TABLE Inputs Geometric layout of pipe Pipe support configuration Pipe diameter and thickness

Outputs Stress in piping system for different loading conditions Expansion of piping system in different operating temperatures Deflection of piping system under occasional loading

Pressure inside the pipe

Correctness of the selection f load

Cold and hot temperature of pipe

Load at various supports and restrains

Weight of pipe and insulation

Movement of pipe at support locations

Weight of carrying fluid

Pipe terminal point loading

Pipe material property

Allowable limit for the nozzle loads

Occasional loads (seismic, snow, …) Corrosion allowance of pipe Bend radius, Any transient load like steam hammer

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5.2.6

PIPE SUPPORTS: Supports are provided to the pipe mainly for the following reasons: ™ To Support dead weight of Piping system ™ To minimize Pipe Sagging ™ To take Expansion load in the Piping system ™ To absorb wind load and Seismic load ™ To absorb Vibration in the Piping system ™ To absorb Hydraulic Thrust in the Piping system ™ To absorb the Pressure Thrust of Bellow ™ To Support the system during Shut down/ Maintenance Conditions. Various types of supports available are: Guide Support: This type of support is used to restrict lateral movement of pipe. This is used in combination with rest support. This type of support also can be used to restrict vertically upward movement of pipe. Restraints Support: This type of support is used to restraint movement of pipes in specific direction based on job need .This type is used in combination with rest and guide support. Anchor Support: This type of support is usually used for segmenting the piping network to restrict the movements of pipe of reasonable amount within the defined piping network. This type of support does not allow movement in any direction. i.e. it ceases all axial, lateral, and torsional movements offered by piping network. It can be achieved by welding the support component to pipe and supporting structures or by using a combination of rest, guide and restraint support.

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Rest Support: This type of support is used to transfer the static load of pipe, content, insulation and piping components to control the sagging phenomenon i.e; deflection of piping network within allowable limits. Rest support allows movements of pipe in all directions except vertically downward movements. Rest support means pipe resting directly on supporting structure on a saddle plate or pipe shoe. Rigid hangers & supports: Rigid hangers are used at suspension points where there is no vertical pipe movement. Where as rigid support is given from the bottom &usually rests on the

floor. E.g.: Pipe shoe,, U –clamp,

Variable effort hangers/ supports and Constant effort hangers/ supports: These two come under flexible support using helical coil compression spring. Variable pipe support is used to support the weight of the pipe work while allowing a degree of movement relative to the supporting structure. Constant pipe support is used to support the pipe work in the case of large vertical movement. ™ Spring loaded sway braces ™ Dynamic restraints/ rigid struts ™ Snubbers /shock absorber

Based on the construction

Based on the functions

1

Rigid support: Welded type, Bolted type

Loose/ resting support

2

Adjustable support

Longitudinal guide support

3

Elastic/ flexible support : Constant Snubber, Variable Snubber

4

As required

5

As required

Transverse guide support Anchor support: welded type Non-welded type Limit stop

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INPUTS REQUIRED FOR THE SELECTION OF PIPE SUPPORTS ™ Piping general arrangement drawing. ™ Steel and structural drawing. ™ Equipment foundation drawing. ™ Location of ventilating ducts, electrical trays, pumps, tanks, etc., ™ Piping specifications and line list. ™ Insulation specification. ™ Valves and special fittings list. ™ Determination of support location ™ Determination of thermal movement of the piping at each support location ™ Calculation of load at each support location. ™ Selection of the type of support i.e., anchor, guide, rest, constant or variable spring, etc., ™ Checking the physical interference of the support with structures, trays, ducts & equipment, etc., 5.3

SOFTWARE USED IN PIPING DEPARTMENT ™ PDS 7.02/8 ™ PDMS 11.5 ™ ISOGEN 7.0 ™ ORTHOGEN 8.000.19 ™ Navis works 5.3/5.5 for 3D Model review package ™ ACAD 2007/2008 for 2D Drawing preparation ™ Micro station 7.01/8 for 2D / 3D drawing preparation ™ CEASER II Ver5.007 – Stress Analysis Package

5.4

IMPORTANT CODES AND STANDARDS

ANSI

-

American National Standards Institute

API

-

American Petroleum Institute

ASME

-

American Society of Mechanical Engineers

ASTM

-

American Society for Testing and Materials

AWWA

-

American water works association.

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Pipe Standard Pipes shall conform to ™ API 5L, ™ ANSI B36.10 for Carbon steel ™ ANSI B36.19 for Stainless steel ™ Based on chemical and material composition several codes applied AMERICAN STANDARDS API STANDARDS

API 5L

Specification for Seamless and Welded Steel Line Pipes

API 6D

Specification for Pipeline Valves, Gate, Plug, Ball and Check

API 600

Steel Gate Valves, Flange and Butt Welding Ends

API 601

Metallic gasket for refinery piping

API 609

Lug- and Wafer-Type butterfly Valves

API RP 14E

Design & Installation of Offshore platform piping systems

API RP 521

Guide for Pressure Relieving systems

ASME STANDARDS

ASME B16.5

Steel Pipe Flanges and Flanged Fittings

ASME B16.9

Factory Made Wrought Steel Butt Welding Fittings

ASME B16.10

Face to Face and End to End Dimensions of Valves

ASME B16.11

Forged Fittings, Socket-Welding and Threaded

ASME B16.20

Metallic Gaskets for Pipe Flanges

ASME B36.10

Welded and Seamless Wrought Steel Pipe

ASME B36.19

Stainless steel Pipe

ASME B31.3

Process Piping

ASME B16.5

Pipe flanges and fittings (”24”)

ASME B16.47

Large diameter flanges (>24”)

ASME B31.4

Pipeline Transportation Systems for Liquid Hydrocarbons & other liquids

ASME B31.8

Gas Transmission & Distribution Piping Systems

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ASTM STANDARDS

ASTM A 53

Welded and seamless pipe

ASTM A 106

Seamless CS pipe for high temperature services

ASTM A 312

Seamless and welded austenitic stainless steel pipes

ASTM A 333

Seamless and welded steel pipe for low temperature service

ASTM A 335

Seamless ferritic alloy steel for high temperature service

ASTM B 423

Incoloy piping material

AWWA STANDARDS AWWA C207 Steel Pipe Flanges for Waterworks Service examination of welded joints AWWA C950 Fibreglass Pressure Pipe 5.5

CALCULATIONS:

5.5.1

Design of pipe wall thickness The piping wall thickness is one of the most important calculations of the piping system design process. In arriving at the final specification of the piping wall thickness, the designer must consider a number of important factors: ™ Pressure integrity ™ Allowances for mechanical strength, corrosion, erosion, wear, threading, grooving, or other joining processes ™ Manufacturing variations (tolerance) in the wall thickness of commercial pipe ™ Wall thickness reduction due to butt-welding of end preparation (counterboring) While a number of different pipe wall thickness design formulas have been proposed over the years, the ASME piping codes have adopted one or the other of the following formulas for pressure-integrity design: Thickness (tm) = (PD / 2(SE+PY)) + A Where, tm = Minimum thickness P = Internal design gauge pressure D = Outside diameter as per standard S = Stress value for material E = Joint Efficiency factor

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Y = Coefficient of material for that design temperature 5.5.2

Stress Analysis Case Study for Combined Cycle Power Plant Piping stress analyses is a term applied to calculations which address the static and dynamic loading resulting from the effects of gravity, temperature changes, internal and external pressures, changes in fluid flow rate, seismic activity, fire, and other environmental conditions. Codes and standards establish the minimum scope of stress analyses. Some codes prescribe loading combinations with not-to-exceed stress limits. The High Pressure (HP) steam system is designed per ASME-B31.1(Power Piping Code) to convey HP superheated steam, from the HP superheater outlet to the high pressure section of the steam turbine. HP steam line is provided with a bypass line, with a combined pressure reducing and steam desuperheating valve and is connected to the Condenser. ™

Normal Operation

™

Start-Up/Shutdown Operation

5.5.2.1 Input Data: Pipe Size

=

8 inches for Main Steam Pipe

Pipe Thickness

=

160 Sch

Insulation Thickness

=

7.5 inches

Pipe size

=

24 inches for Bypass connection

Pipe Thickness

=

STD

Insulation Thickness

=

2.5 inches

Design Temperature

=

955.4 ° F

Design Pressure

=

1450 psi

Pipe Material

=

ASTM A335 P22

Insulation Material

=

Calcium silicate per ASTM C533 for heat retention

Pipe Construction

=

Seamless

Flange type

=

Not Allowed

ASTM Spec.

=

B16.9, B16.28

Type

=

Butt Weld

Fittings Greater than 2 inch

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Fittings Less than 2 inch ASTM Spec.

=

A182 F22

ASME STD. Type

=

B16.11

Rating

=

9000 Class

Type

=

Socket Weld

Attemperator weight

=

1322.5 lbs per 7.87ft

5.5.2.2 Pipe Behaviour in Thermal Condition - Iteration –I

Maximum stressed Node - Iteration I NODE

NODE TYPE

STRESS (PSI)

ALLOWABLE

RATIO

STRESS (PSI)

95

8

144000

29180.

4.935

320

1

60800.

29028.

2.095

50

1

42200.

28083.

1.503

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5

7

33000.

28619.

1.153

55

8

31400.

28639.

1.096

™ Ratio is more than 1, means that the stresses are exceeding the allowable stress limits and thus the nodes get fails. Equipment Nozzle reaction HRSG LOAD CASE

ORCES (LBS)

MOMENTS (FT-LBS)

HOT & WEIGHT

FR = 4082

MR = 60244.

COLD & WEIGHT

FR = 3516

MR = 72069

HOT & WEIGHT

FR = 6068

MR = 36673.

COLD & WEIGHT

FR = 6679

MR = 44044.

HOT & WEIGHT

FR = 1102

MR = 6646.

COLD & WEIGHT

FR = 1734

MR = 9026.

Turbine

Condenser

Pipe Behaviour In Thermal Condition - Iteration –II

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Maximum stressed Node - Iteration II

NODE

NODE (TYPE )

STRESS (PSI)

RATIO

24500

ALLOWABLE STRESS (PSI) 29443

325

11

305

8

21700

29332

0.740

5

7

19800

28606

0.692

330

7

18600

29494

0.631

55

8

16000

28651

0.558

95

8

14400

29015

0.496

0.832

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Equipment Nozzle reaction HRSG LOAD CASE

FORCES (LBS)

MOMENTS (FT-LBS)

HOT & WEIGHT

FR = 3924

MR = 56488.

COLD & WEIGHT

FR = 3260

MR = 67373

HOT & WEIGHT

FR = 5983

MR = 33526.

COLD & WEIGHT

FR = 6503

MR = 40128

Turbine

Condenser HOT & WEIGHT

FR = 1109

MR = 9508.

COLD & WEIGHT

FR = 1674

MR = 12032

Final Iteration As the same Lot of trail and error iteration has been done to keep the pipe within permissible limit in dead weight, minimum stresses at all nodes and all the three equipment nozzles within the allowable limits as specified by the manufacturer of the same. Finally by doing lot of iteration the best solution has arrived which gives Minimum stresses in Piping, Meets the code limits, Meets the Equipment forces and moments.

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5.6

PIPING MATERIAL SELECTION CHART: This chart tells the material to be used for plates, pipes, flanges, fittings, bolting for different range of temperature.

MATERIAL SELECTION GUIDE

Cryogenic

Design Temperature, °FMaterial

SA-240-304, -425 to -321 Stainless Steel

304L, 347, 316, 316L

Low Temperature

-320 to -151 9 Nickel 3½ Nickel

SA-203-D

-75 to -51

2½ Nickel

SA-203-A SA-516-55, 60

-50 to -21

to SA-20

-20 to 4 5 to 32

Intermediate

SA-353

-150 to -76

SA-516-All Carbon Steel

33 to 60 61 to 775 776 to 875

Elevated Temperature

Plate

SA-312304, 304L, 347,316, 316L SA-333-8 SA -333-3

Forgings SA-182-304,

Fittings SA-403-304,

304L, 347,

304L,

SA-320-B8 with

316, 316L

347,316, 316L

SA-194-8

SA-522-I

SA-420-WPL8

SA-350LF63

SA-420-WPL3

SA-194-4

SA-333-6 SA-350-LF2

SA-420-WPL6

SA-333-1 or 6

SA-516-All

SA-53-B

SA-105 SA-

SA-515-All

SA-106-B

181-60, 70

SA-204-B

1Cr-½Mo

SA-387-12-1

1¼Cr-1Mo

SA-387-11-2

1001 to 1100 2¼Cr-½Mo

Stainless 1101 to 1500 Steel Incoloy Inconel100

SA-320-L7 with

SA-234-WPB SA-193-B7

SA-455-II C-½Mo

Bolting

SA-285-C

876 to 1000

1500

Pipe

SA-387-22-1

SA-240-347H

with SA-335-P1 SA-335P12 SA-335P11 SA-335P22

SA-182-F1

SA-234-WP1

SA-182-F12

SA-234-WP12

SA-182-F11

SA-234-WP11

SA-194-2H

SA-193-B5 SA-182-F22

SA-234-WP22

with SA-194-3

SA-312-

SA-182-

347H

347H

SA-403-347H SA-193-B8

SB-424

SB-423

SB-425

SB-366

SB-443

SB-444

SB-446

SB-366

with SA-194-8

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5.7

STANDARD FORMAT USED FOR:

5.7.1

PIPING MATERIAL SPECIFICATION PIPING CLASS DESIGNATION KEY Flange Class :( in pounds) ™ 150 ™ 300 ™ 600 ™ 900 ™ 1500 ™ 2500 ™ PN160 BAR. ™ PN 200/325/500 BAR (IG STANDARD). Piping Material: ™

C.S, ASTM A 106, GR.B / API 5L, GR.B

™

C.S, ASTM A333, GR.6 (LOW TEMP).

™

C.S, ASTM A335, GR.P11 (HIGH TEMP).

™

S.S, ASTM A312, GR.TP316L

™

S.S, ASTM A312

™

S.S, SMo (AVESTA 254 SMo ).

™

S.S, ASTM A312

™

C.S, ASTM A335, GR.P91 / P22

™

GRP

™

Duplex

™

Safurex

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PRODUCT CODE: AC

-

Compressed Process Air

AL

-

Ammonia Liquid

AM

-

Ammonia Vapour

AP

-

Process Air (Uncompressed)

AQ

-

Aqueous Ammonia

AF

-

Flash Gas

BH

-

Boiler Blow Down

CD

-

Carbon Dioxide

CL

-

Steam Condensate LP 6,9 / 7/ 6 barg

CT

-

Purified Process Condensate

CX

-

Steam Condensate HP 125 barg

CY

-

Steam Condensate MP 55 barg

GM

-

Methanated Gas

GV

-

Convert Gas

GN

-

Natural Gas

SV

-

Vapor (Contaminated Steam)

NI

-

Nitrogen

DR

-

Drains (Compr. House)

RW

-

Recirculation Cooling Water

WF

-

Boiler Feed Water

SM

-

Steam MP 26 barg (Sat. & Superh.)

SL

-

SteamLP 6.9 / 7 / 6 barg (Sat. & Superh.)

SX

-

Steam HP 125 barg (Sat. & Superh.)

The first letter in the pipe class represents the flange class, second letter represents the piping material and third letter represents the serial number

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Piping Material Specifications summary table: PIPE CLASS AB2

MINIMUM CORROSION

FLUIDS

MATERIAL

ALLOWANCE 1.6 mm

AL,AM

PRESSURE RATING

A333, Gr.6

# 150

BB2

1.6 mm

AL, AM

A333, Gr.6

# 300

FB1

1.6 mm

AL

A333, Gr.6

#1500

AC, AF, AP, AQ, AT, AA4

1.6 mm

BH, CD, CL, CT, CX,

A106, Gr.B/

CY, GM, GV, NI, SL,

API 5L, Gr.B

# 150

SV,SY,WA,WF, SM A106, Gr.B/ AA5

1.6 mm

AM,GB, GN

# 150 API 5L,Gr.B A106, Gr.B/

AA6

1.6 mm

CW, DR, RW

# 150 API 5L,Gr.B

AA7

1.6 mm

MS

A106, Gr.B

# 150

AA8

1.6 mm

MS

A106, Gr.B

# 150

AF,AP,AQ,CD,CL,CP BA4

1.6 mm

DR,GI,GM,GV,HY,NI,

A106,Gr.B/

RW, SM,SL,SX,SY,WF,

API 5L,Gr.B

# 300

CM

5.7.2

VALVE SCHEDULE: Valve schedule is a document containing the database of valves which are used in a project. This is prepared during the detailed engineering for reference Valve schedule contains: ™ Valve tag no ™ Operation mode of the valve ™ Type of the valve

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™ Seat material ™ Body material ™ Process connection ™ Line no, datasheet no, model no, P&ID reference no ™ Name of the supplier and manufacturer ™ Bore type-full/ reduced ™ Application The valve schedule is developed taking data from line P&ID, line list, data sheet. 5.8

SPECIALITY ITEMS

5.8.1

STRAINERS: It is a screen installed in the pipe lines to allow the liquid to flow and to restrict the solid particles. These solid / larger items fall to the bottom or are collected in a basket for later clean out. The se strainers come in different styles based on the needs. Two common types of strainers are: Plate Strainer is the one in which liquid flows through a perforated plate. Often this plate is corrugated to increase the surface area. Basket strainer is the one in which strainer is shaped like a basket and usually installed in a vertical cylinder. The basket strainer is easier to clean and also offers more straining surface area than a plate strainer improves the flow rate or decreases the pressure loss through the strainer.

5.8.2

STEAM TRAP: The duty of the steam trap is to discharge the condensate and non-condensable gases while not permitting the escape of live steam. Almost all steam traps are automated valves which open, close or modulate automatically. Steam traps are broadly classified based on their applications: Mechanical traps: they have a float that rises and falls with respect to condensate level ands have a mechanical linkage attached which opens and closes the valve. E.g. inverted bucket, float type. Temperature traps: they have a valve that is driven on/ off either by expansion/ contraction caused by temperature change. Thermo-dynamic Traps: they work on the difference in dynamic response to velocity change in the flow of compressible and incompressible fluids. As steam enters, static pressure above the disk forces the disk against valve seat. The static pressure over a large area overcomes the high

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inlet pressure of the steam. As the steam starts to condense, the pressures against the disk lessens and trap cycles. 5.8.3

EXPANSION BELLOWS: Expansion bellows are used to accommodate expansion in piping due to temperature changes if such movements cannot be taken by expansion loops, cold springing, re routing and re spacing of pipe.

5.9

GENERAL ABBREVATIONS AND DEFINITIONS

5.9.1

GENERAL ABBREVIATIONS: ABS

Absolute

ANSI

American National Standards Institute

API

American Petroleum Institute

ASTM

American Society of Testing and Materials

ASME

American Society of Mechanical Engineers

AWWA

American Waterworks Association

AWS

American Welding Society

BS

British Standards

BW

Butt-Welding ends

CI

Cast Iron

CS

Carbon Steel

DN

Nominal Diameter

ERW

Electric Resistance Welded

FB

Full Bore

FF

Flat Face

F/F

Face to Face

ID

Inside Diameter

ND

Nominal Diameter

NB

Nominal Bore

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5.9.2

NPS

Nominal Pipe Size

OD

Outside Diameter

PE

Plain Ends

PN

Nominal Pressure

RB

Reduced Bore

RF

Raised Face

RTJ

Ring-Type Joint

Sch

Schedule (wall thickness)

SS

Stainless Steel

SW

Socket Weld

GENERAL DEFINITIONS: Alloy Steel: A steel which owes its distinctive properties to elements other than carbon. Steel is considered to be alloy steel when the maximum of the range given for the content of alloying elements exceeds one or more of the following limits: Manganese 1.65 percent Silicon 0.60 percent Copper 0.60 percent or a definite range or a definite minimum quantity of any of the following elements is specified or required within the limits of the recognized field of constructional alloy steels: Aluminum Nickel Boron Titanium Chromium (up to 3.99 percent) Tungsten Cobalt Vanadium Columbium Zirconium Molybdenum or any other alloying element added to obtain a desired alloying effect. Small quantities of certain elements are unavoidably present in alloy steels. In many applications, these are not considered to

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be important and are not specified or required. When not specified or required, they should not exceed the following amounts: Copper 0.35 percent Chromium 0.20 percent Nickel 0.25 percent Molybdenum 0.06 percent Anchor: A rigid restraint providing substantially full fixation, permitting neither translatory nor rotational displacement of the pipe. Blind Flange: A flange used to close the end of a pipe. It produces a blind end which is also known as a dead end. Branch Connection: The attachment of a branch pipe to the run of a main pipe with or without the use of fittings. Carbon Steel: A steel which owes its distinctive properties chiefly to the carbon (as distinguished from the other elements) which it contains. Steel is considered to be carbon steel when no minimum content is specified or required for aluminum, boron, chromium, cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, or zirconium or for any other element added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 percent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese, 1.65 percent; silicon, 0.60 percent; copper, 0.60 percent.2 Cast Iron: A generic term for the family of high carbon-silicon-iron casting alloys including gray, white, malleable, and ductile iron. Cold Bending: The bending of pipe to a predetermined radius at any temperature below some specified phase change or transformation temperature but especially at or near room temperature. Frequently, pipe is bent to a radius of 5 times the nominal pipe diameter. Companion Flange: A pipe flange suited to connect with another flange or with a flanged valve or fitting. A loose flange which is attached to a pipe by threading, van stoning, welding, or similar method as distinguished from a flange which is cast integrally with a fitting or pipe. Continuous-Welded Pipe: Furnace weldedpipe produced in continuous lengths from coiled skelp and subsequently cut into individual lengths, having its longitudinal butt joint forge welded by the mechanical pressure developed in rolling the hot-formed skelp through a set of round pass welding rolls.

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Control Piping: All piping, valves, and fittings used to interconnect air, gas, or hydraulically operated control apparatus or instrument transmitters and receivers. Coupling: A threaded sleeve used to connect two pipes. Commercial couplings have internal threads to fit external threads on pipe.. Ductile Iron: A cast ferrous material in which the free graphite is in a spheroidal form rather than a fluke form. The desirable properties of ductile iron are achieved by means of chemistry and a ferritizing heat treatment of the castings. Electric Flash-Welded Pipe: Pipe having a longitudinal butt joint in which coalescence is produced simultaneously Edge preparation. Over the entire area of abutting surfaces by the heat obtained from resistance to the flow of electric current between the two surfaces and by the application of pressure after heating is substantially completed. Flashing and upsetting are accompanied by expulsion of metal from the joint. Electric Fusion-Welded Pipe: Pipe having a longitudinal or spiral butt joint in which coalescence is produced in the preformed tube by manual or automatic Electric arc welding. The weld may be single or double and may be made with or without the use of filler metal. Electric Resistance-Welded Pipe: Pipe produced in individual lengths or in continuous lengths from coiled skelp and subsequently cut into individual lengths having a longitudinal butt joint in which coalescence is produced by the heat obtained from resistance of the pipe to the flow of electric current in a circuit of which the pipe is a part and by the application of pressure. Extruded Pipe: Pipe produced from hollow or solid round forgings, usually in a hydraulic extrusion press. In this process the forging is contained in a cylindrical die. Initially a punch at the end of the extrusion plunger pierces the forging. The extrusion plunger then forces the contained billet between the cylindrical die and the punch to form the pipe, the latter acting as a mandrel.One variation of this process utilizes autofrettage (hydraulic expansion) and heat treatment, above the recrystallization temperature of the material, to produce a wrought structure. Forged and Bored Pipe: Pipe produced by boring or trepanning of a forged billet. Hangers and Supports: Hangers and supports include elements which transfer the load from the pipe or structural attachment to the supporting structure or equipment. They include hanging-type fixtures such as hanger rods, spring hangers, sway braces, counterweights, turnbuckles, struts, chains, guides, and anchors and bearing-type fixtures such as saddles, bases, rollers, brackets, and sliding supports.

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Header: A pipe or fitting to which a number of branch pipes are connected. Hot Bending: Bending of piping to a predetermined radius after heating to a suitably high temperature for hot working. On many pipe sizes, the pipe is firmly packed with sand to avoid wrinkling and excessive out-of-roundness. Instrument Piping: All piping, valves, and fittings used to connect instruments to main piping, to other instruments and apparatus, or to measuring equipment.2 Kinematic Viscosity: The ratio of the absolute viscosity to the mass density. In the metric system, kinematic viscosity is measured in strokes or square centimeters per second. Lapped Joint: A type of pipe joint made by using loose flanges on lengths of pipe whose ends are lapped over to give a bearing surface for a gasket or metal-to-metal joint. Nipple: A piece of pipe less than 12 in (0.3 m) long that may be threaded on both ends or on one end and provided with ends suitable for welding or a mechanical joint. Pipe over 12 in (0.3 m) long is regarded as cut pipe. Common types of nipples are close nipple, about twice the length of a standard pipe thread and without any shoulder; shoulder nipple, of any length and having a shoulder between the pipe threads; short nipple, a shoulder nipple slightly longer than a close nipple and of a definite length for each pipe size which conforms to manufacturer’ standard; long nipple, a shoulder nipple longer than a short nipple which is cut to a specific length. Pipe Alignment Guide: A restraint in the form of a sleeve or frame that permits the pipeline to move freely only along the axis of the pipe. Pipe Supporting Fixtures: Elements that transfer the load from the pipe or structural attachment to the support structure or equipment. Pipeline or Transmission Line: A pipe installed for the purpose of transmitting gases, liquids, slurries, etc., from a source or sources of supply to one or more distribution centers or to one or more large-volume customers; a pipe installed to interconnect source or sources of supply to one or more distribution centers or to one or more large-volume customers; or a pipe installed to interconnect sources of supply. Piping System: Interconnected piping subject to the same set or sets of design conditions.

Purging: The displacement during welding, by an inert or neutral gas, of the air inside the piping underneath the weld area in order to avoid oxidation or contamination of the underside of the weld. Gases most commonly used are argon, helium, and nitrogen (the last is principally limited

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to austenitic stainless steel). Purging can be done within a complete pipe section or by means of purging fixtures of a small area underneath the pipe weld. Saddle Flange: Also known as tank flange or boiler flange. A curved flange shaped to fit a boiler, tank, or other vessel and to receive a threaded pipe. A saddle flange is usually riveted or welded to the vessel. Schedule Numbers: Approximate values of the expression 1000P/S, where P is the service pressure and S is the allowable stress, both expressed in pounds per square inch. Seamless Pipe: A wrought tubular product made without a welded seam. It is manufactured by hot-working steel or, if necessary, by subsequently cold-finishing the hot-worked tubular product to produce the desired shape, dimensions, and properties. Socket Weld: Fillet-type seal weld used to join pipe to valves and fittings or to other sections of pipe. Generally used for piping whose nominal diameter is NPS 2 (DN 50) or smaller. Source Nipple: A short length of heavy-walled pipe between high-pressure mains and the first valve of bypass, drain, or instrument connections. Spiral-Welded Pipe: Pipe made by the electric-fusion-welded process with a butt joint, a lap joint, or a lock-seam joint. Stainless Steel: An alloy steel having unusual corrosion-resisting properties, usually imparted by nickel and chromium. Swivel Joint: A joint which permits single-plane rotational movement in a piping system. Tack Weld: A small weld made to hold parts of a weldment in proper alignment until the final welds are made. Tee Joint: A welded joint between two members located approximately at right angles to each other in the form of a T. Tube: A hollow product of round or any other cross section having a continuous periphery. Round tube size may be specified with respect to any two, but not all three, of the following: outside diameter, inside diameter, and wall thickness. Dimensions and permissible variations (tolerances) are specified in the appropriate ASTM or ASME specifications. Welding Fittings: Wrought- or forged-steel elbows, tees, reducers, and similar pieces for connection by welding to one another or to pipe. In small sizes, these fittings are available with counter bored ends for connection to pipe by fillet welding and are known as socket-weld fittings. In large sizes, the fittings are supplied with ends chamfered for connection to pipe by means of butt welding and are known as butt-welding fittings.

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Wrought Pipe: The term wrought pipe refers to both wrought steel and wrought iron. Wrought in this sense means ‘‘worked,’’ as in the process of forming furnace welded pipe from skelp or seamless pipe from plates or billets. The expression wrought pipe is thus used as a distinction from cast pipe. Wrought pipe in this sense should not be confused with wrought-iron pipe, which is only one variety of wrought pipe. When wrought-iron pipe is referred to, it should be designated by its complete name.

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