Pressure Testing for Piping and Equip.pdf
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ENGINEERING STANDARDS
PIPING, PRESSURE TESTING FOR PIPING AND EQUIPMENT ES-PPG-1201
The information contained in this document is confidential and proprietary to NOVA Chemicals and may not be disclosed in whole or in part to any other individual or organization without the prior written consent of NOVA Chemicals. Use of this information for any purpose other than that authorized by NOVA Chemicals is strictly prohibited. Rev. No.: 03 Original Issue Date:
18.08.1999
Rev. Date: 10.01.2013
Leadership Approval:
Peter Dolinsek
Doug Rogge
Dave Richmond
Engineering & Technical Services Leader, ME
Director of Engineering, MS
Technical Services Leader, MW
Technical Approval:
Dave May Form: ES-DOC-7007
Frank Wagner
Eric Wong 24.04.1998
is a registered trademark of NOVA Brands Ltd.; authorized use
John Vanden Hoven Page i of i
ENGINEERING STANDARDS REVISION REGISTER Standard Number: Standard Name: Rev # 01
ES-PPG-1201 Piping, Pressure Testing For Piping and Equipment
Rev to
Approved
by
by
Date
Add new clause to clarify unpainted pipe at
26.01.07
G. Laevens
E. Wong
07.07.08
G. Laevens
G. Laevens
10.01.13
G. Laevens
N.
Section # 8.4
Reviewed
Description
hydrotest 02
Remove sentence as per Gary’s email on 24-Jun-
8.2.2
08 as per Change Request C07-09-PPG-281 03
2.2,
5.1.2,
Removed reference to ES-PPG-1504.
P /
8.1.3.9,
Temperature tables are now available with each
8.2.2,
Piping Class Datasheet
Mastrobuono
8.4.19, 16
Form: ES-DOC-70013
08.10.1999
Page 1 of 1
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 3 of 34 03 10.01.2013
TABLE OF CONTENTS Page No.: 1.
GENERAL .................................................................................................................................. 5 1.1 Scope .............................................................................................................................. 5 1.2 Units of Measurement ..................................................................................................... 6 1.3 Definition of Terms .......................................................................................................... 6
2.
STANDARDS, CODES AND REGULATIONS ........................................................................... 6 2.1 General ........................................................................................................................... 6 2.2 NOVA Engineering Standards ......................................................................................... 6 2.3 Industry Standards and Codes ........................................................................................ 7
3.
GOVERNANCE OF DOCUMENTS ............................................................................................ 7 3.1 General ........................................................................................................................... 7
4.
QUALITY ASSURANCE (QA) AND QUALITY CONTROL (QC) ................................................ 7 4.1 General ........................................................................................................................... 7
5.
GENERAL REQUIREMENTS ..................................................................................................... 8 5.1 Extent of Testing ............................................................................................................. 8 5.2 Safety .............................................................................................................................. 8 5.3 Selection of Testing Methods .......................................................................................... 9
6.
REQUIRED EXAMINATIONS AND TESTS.............................................................................. 10
7.
PREPARATION FOR TESTING ............................................................................................... 10 7.1 General ......................................................................................................................... 10 7.2 Isolation......................................................................................................................... 10 7.3 Test Gauges ................................................................................................................. 10 7.4 Registration Requirements ............................................................................................ 11
8.
HYDROSTATIC TESTING ....................................................................................................... 11 8.1 Test Medium ................................................................................................................. 11 8.2 Test Methods and Pressures......................................................................................... 12 8.3 Hydrostatic Testing of Piping Designed for External Pressure ....................................... 14 8.4 Hydrostatic Test Procedure ........................................................................................... 14 8.5 Testing of Polyethylene Lines ........................................................................................ 17
9.
PNEUMATIC TESTING ............................................................................................................ 18 9.1 General ......................................................................................................................... 18 9.2 Safety Procedure .......................................................................................................... 18 9.3 Test Medium ................................................................................................................. 18 9.4 Test Pressure ................................................................................................................ 19 9.5 Test Temperature .......................................................................................................... 19
NOVA Chemicals Issue Date:
18.08.1999 9.6 9.7 9.8 9.9 9.10 9.11
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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Organization .................................................................................................................. 20 Pneumatic Test Procedure ............................................................................................ 21 Cautionary Notes .......................................................................................................... 21 Safety ............................................................................................................................ 22 Communications ........................................................................................................... 23 Equipment ..................................................................................................................... 23
10.
VESSELS AND EQUIPMENT .................................................................................................. 23
11.
INSTRUMENTS AND CONTROL VALVES .............................................................................. 24
12.
TEST RECORDS ...................................................................................................................... 25
13.
TEST COMPLETION ................................................................................................................ 25
14.
PRESSURE TEST BLINDS ...................................................................................................... 27
15.
ALTERNATIVE TESTS (NOVA APPROVAL REQUIRED) ...................................................... 27 15.1 General Service ............................................................................................................ 27 15.2 Commodity Test for Category 'D' Fluid Service Only ..................................................... 28 15.3 Tightness Test............................................................................................................... 28
16.
TABLES ................................................................................................................................... 29
17.
APPENDIX A – DEFINITION OF TERMS................................................................................. 32 17.1 Definitions of Standard Engineering Terms ................................................................... 32 17.2 Definitions of Engineering Discipline Terms .................................................................. 33
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 5 of 34 03 10.01.2013
1.
GENERAL
1.1
Scope
1.1.1
This Standard defines the minimum requirements and procedures for shop and field pressure testing of piping systems, connected equipment and integral components for NOVA Chemicals Corporation (hereinafter referred to as ‘NOVA’).
1.1.2
Regulatory officials having jurisdiction in the area shall be advised in advance of all field pressure testing. Regulatory Inspectors may at their option witness the testing. Test records shall be per Section 12. Piping system registration numbers required by the regulatory body having jurisdiction in the area (e.g.: in Ontario, ‘P’ -numbers) shall be available prior to the test.
1.1.3
Boiler external piping under the jurisdiction of ASME B31.1 shall be hydrostatically tested in accordance with ASME Section I, Power Boilers.
1.1.4
Exclusions The following systems are excluded from the requirements of this Standard:
1.1.4.1 Atmospheric sewers and drains that are tested in accordance with other NOVA specifications. 1.1.4.2 Plumbing systems that are tested in accordance with the applicable plumbing codes. 1.1.4.3 Lines and systems open to the atmosphere unless otherwise noted. Any such lines or systems that may have a mode of operation that causes internal pressures to exceed 14 psig and / or dynamic loading due to high flow rates, and / or multi-phase flow, shall be pressure tested in accordance with the requirements specified on the piping drawings and job specifications. Particular attention must be given to testing safety and relief valve discharge lines, whether discharging to atmosphere or to closed systems. See also NOVA Engineering Standard ES-PPG-0201 Piping, Design and Layout. 1.1.4.4 Instrument piping lead lines between the root valve at the process or utility line and the connected instrument and control piping used to connect air or hydraulically operated control apparatus. 1.1.4.5 Equipment such as fired tubular heaters, rotating equipment casings or housings such as pumps, compressors and steam turbines. 1.1.4.6 Polyethylene or other non-metallic pressure pipe with high creep / expansion properties. 1.1.4.7 Brittle components such as Duriron, glass, fused silica, Karbate or ceramics should be removed or isolated prior to pressure testing.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date:
18.08.1999
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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1.1.5
No variation shall be made from this Standard without prior completion and approval of a NOVA Engineering Standards Variance Form (No. SPF-012).
1.1.6
Where approval is indicated in this Standard, this refers to NOVA or its designated representative.
1.2
Units of Measurement
1.2.1
All units of measurement are expressed in English Units (U.S. Conventional System of Measurement) followed by the International System of Metric Units (SI) in parentheses.
1.2.2
Refer to NOVA Engineering Guideline EG-PPG-0101 Piping, Units Conversion Guideline for pressure rating designations, nominal size designations and unit conversions applicable to Valves (VLV) and Piping (PPG) standards.
1.3
Definition of Terms
1.3.1
The definitions of standard engineering and discipline terms used throughout this Standard are listed in Appendix ‘A’.
2.
STANDARDS, CODES AND REGULATIONS
2.1
General
2.1.1
NOVA representatives and its suppliers are responsible for identifying, issuing and using copies of the applicable editions / addenda of NOVA Standards, and Industry Standards and Codes, cited in Sections 2.2 and 2.3 below.
2.2
NOVA Engineering Standards 1. EG-PPG-0101
Piping, Units Conversion Guideline
2. ES-PPG-0201
Piping, Design and Layout
3. ES-PPG-0702
Piping, Gaskets for Pipe Flanges
4. ES-PPG-1101
Piping, Internal Cleaning Procedures
5. ES-PPG-1501
Piping, Line Class Designation
6. EG-PPG-1502
Piping, Design Guideline for Piping Class Datasheets
ENGINEERING STANDARDS
NOVA Chemicals Issue Date: 2.3
18.08.1999
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 7 of 34 03 10.01.2013
Industry Standards and Codes 1. ASME B16.5
Pipe Flanges and Flanged Fittings
2. ASME B31.1
Power Piping
3. ASME B31.3
Chemical Plant and Refinery Piping
4. CSA B51
Boiler, Pressure Vessel and Pressure Piping Code
5. ASME Code, Section I, Section V and Section VIII – Division 1 3.
GOVERNANCE OF DOCUMENTS
3.1
General Where variances occur between the documents explaining the work, the following order of precedence will govern as they apply:
3.1.1
Purchasing Document
3.1.2
The Scope of Work
3.1.3
Drawings / Specifications / Standards In the case of variances or inconsistencies between the drawings, specifications or standards, the supplier(s) shall consult with the NOVA representative for a decision before proceeding with the work.
4.
QUALITY ASSURANCE (QA) AND QUALITY CONTROL (QC)
4.1
General Various responsibilities exist to ensure that QA and QC in NOVA Engineering Standards for products and services will be met. This will include, but not be limited to, all suppliers (manufacturers, fabricators, contractors, sub-contractors, laboratories, distributors and vendors). The responsibilities for QA and QC are defined as follows:
4.1.1
The Supplier shall be Responsible for: Providing quality products or services that meet NOVA’s requirements.
4.1.2
The Supplier shall be Responsible for: Submitting upon request or have available to NOVA, a copy of all approved QC manuals, procedures, test reports, permits, certificates and any other data that is pertinent to the products or services.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 8 of 34 03 10.01.2013
4.1.3
The Supplier shall be Responsible for: Notifying sub-vendors of the NOVA inspection and testing requirements. The supplier shall provide sufficient advance notice to NOVA before conducting any inspection or test that NOVA has specified to be witnessed or observed.
4.1.4
The Supplier shall be Responsible for: Supplying equipment for the specified inspections and tests.
4.1.5
NOVA is Responsible for: Evaluating technical data, performing inspections and witnessing tests as deemed necessary. NOVA will establish and coordinate inspection hold points with the supplier. Accessibility to all suppliers, fabrication shops, manufacturing facilities and test facilities is MANDATORY. NOVA’s acceptance of the results, or its option not to carry out this examination, does not relieve the suppliers from their responsibilities and liabilities with respect to defective materials and workmanship.
4.1.6
NOVA is Responsible for: Ensuring that the NOVA Supply Management Vendor Approval and ‘Quality Audit Program’ is adhered to prior to any products or services being purchased or allowed on site by NOVA.
5.
GENERAL REQUIREMENTS
5.1
Extent of Testing
5.1.1
Prior to initial operation, and subsequent to any repair and heat treatment, all installed piping and equipment shall be pressure tested except where otherwise qualified in this Engineering Standard.
5.1.2
Testing of all piping systems shall be in accordance with the Piping Class Datasheet Pressure / Temperature Rating Table where special requirements may apply in addition to those specified in this Standard
5.1.3
All piping identified as Category ‘M’ Fluid Service shall be subjected to a sensitive leak test prior to hydrostatic testing.
5.2
Safety
5.2.1
Refer to Section 9 for specific safety requirements for pneumatic tests.
5.2.2
During any pressure testing, consideration should be given to cordoning off the test area.
5.2.3
If hydrostatic test pressure is greater than 500 psig, the test area, including a safety zone around all piping and equipment to be tested, shall be cordoned off with high visibility ‘caution tape’, flags, and / or other barriers. Barriers shall be placed such that any personnel not involved with the test are kept at least 50 feet away from any of the tested systems.
NOVA Chemicals Issue Date: 5.3
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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Selection of Testing Methods Selection of testing method shall be in accordance with the following table: System / Service Air, condensate, nitrogen, steam or water with design gauge pressures not exceeding 150 psig (1035 kPa) and design temperatures not exceeding 366°F (186°C), i.e.: Category ‘D’ fluid services Air, condensate, nitrogen, steam or water with design gauge pressures exceeding 150 psig (1035 kPa) or design temperatures exceeding 366°F (186°C) Process lines for internal pressure service with design temperature above 32°F (0°C) Process lines for internal pressure service with design temperature 32°F (0°C) or below, in which water left in lines could cause a problem in operation: Before installation: Hydrostatically test each spool to the maximum test pressure of the governing valves and piping materials specification (Note: Proper notification shall be made on piping isometric drawings requesting such shop tests)
Test Method Commodity (Service) Test
Hydrostatic Test
Hydrostatic or Pneumatic Test Hydro test and Pneumatic Test (see detailed explanation at left)
After installation: Note: Field welds subject to a test pressure exceeding 100 psig (6900 kPa) shall be fully ultrasonically or radiographically examined prior to the test When specifically approved by NOVA, an ‘in-process’ examination may be substituted for the pneumatic test Process lines for vacuum service: Use 50 psig (345 kPa) as minimum test pressure (see paragraph: 8.2.2.1) Short (less than 20 feet [6 meters] overall length) vent, drain and safety relief valve discharge lines (steam, air, nitrogen, water only) open to the atmosphere
All other safety and relief valve discharge lines, whether relieving to closed systems, to atmosphere or to any kind of containment system whether operating at elevated or atmospheric pressure
Hydrostatic or Pneumatic Test No test required (See also NOVA Engineering Guideline ES-PPG-0201 Piping, Design and Layout) Hydrostatic or Pneumatic Test (See also NOVA Engineering Guideline ES-PPG-0201 Piping, Design and Layout)
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 10 of 34 03 10.01.2013
6.
REQUIRED EXAMINATIONS AND TESTS
6.1.1
Prior to initial operation, every piping system shall be checked to assure compliance with codes and regulations, the design and material specifications, the workmanship, fabrication, assembly and all connected components.
6.1.2
NOVA inspection shall verify that all required examinations and tests have been completed prior to pressure testing. This verification shall include certification and records pertaining to material, components, heat treatment, examinations and tests.
6.1.3
Contractors working on piping projects on site shall carry out the required procedures as noted in Sections 6.1.1 and 6.1.2 and shall be responsible for full compliance with this specification.
6.1.4
Fabricators working on piping projects shall carry out the required procedures as noted in Sections 6.1.1 and 6.1.2 and as may be required by NOVA.
7.
PREPARATION FOR TESTING
7.1
General
7.1.1
Preparation for testing shall include preparation for the requirements of Section 12 ‘Test Records’, and Section 13 ‘Test Completion’.
7.2
Isolation
7.2.1
Blind flanges, blanks, caps or plugs shall be installed to isolate piping systems, equipment and instruments where required. See also Section 10 – ‘Vessels and Equipment’, and Section 11 – ‘Instruments and Control Valves’. Minimum thickness of blanks shall be in accordance with Table ‘C’.
7.2.2
Where equipment has been accurately aligned, such as pumps, compressors and turbines, blanks shall not be forced into place between the equipment flange and pipe flange. If the blank cannot be freely slipped into place by hand, an alternative arrangement for closing off the piping shall be used (see also Section 8.3.6).
7.2.3
The open ends of piping shall be blinded off using ASME standard blind flanges.
7.3
Test Gauges
7.3.1
Calibration of gauges and / or charts shall be verified by the Inspector prior to issue for pressure testing. All gauges shall be calibrated every 12 months using a dead weight tester. Gauges shall be tagged with the date last calibrated and the calibration activity shall be recorded. See site Quality Control Manual for gauge testing and records requirements. Any gauge that is suspect shall not be used for pressure testing until repaired and calibrated against a dead weight tester that has been verified within the preceding 12 months.
7.3.2
Some regulatory bodies (e.g.: TSSA in Ontario) require that a minimum of two (2) calibrated test gauges be installed on any pipe, equipment or system being tested.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date:
18.08.1999
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 11 of 34 03 10.01.2013
7.4
Registration Requirements
7.4.1
Prior to testing, any piping system registration numbers required by the regulatory body having jurisdiction in the area (e.g.: in Ontario, ‘P’ numbers) shall be available for the Regulatory Inspector and for entry into the test records.
8.
HYDROSTATIC TESTING
8.1
Test Medium
8.1.1
The test medium shall be water except if there is a possibility of damage due to freezing, or if the operating fluid or piping material would be adversely affected by water, any other suitable liquid may be used with prior NOVA permission. Examples of alternate liquids other than clean water are: De-mineralized water for boiler piping, brine, water glycol mixture or hydrocarbon process fluids with flash point higher than 120oF (50oC).
8.1.2
If testing with glycol-water mixtures or any fluid other than water, the disposal problem of the test fluid shall be considered. Testing of ferritic piping, however, is limited to the temperature restrictions in Section 8.1.3.8.
8.1.3
Test Water Criteria
8.1.3.1 Care shall be taken to insure the use of clean water for these tests. A suitable filter should be provided in the fill line to the systems, should foreign matter such as sand, rust or other particles be in evidence in the proposed test water. 8.1.3.2 Water used for hydrostatic testing of austenitic stainless steel piping, vessels and equipment, including those with austenitic stainless steel claddings, linings or internals (including valve trim) shall conform to the requirements listed below. These requirements apply also to 12 chrome claddings or linings that are welded with austenitic stainless steel weld filler. In any case, the water shall not be left in contact with the stainless steel for more than 72 hours. Test water shall contain no more than 50 ppm chlorides. Water with higher chloride levels may be used with NOVA Engineering approval provided it is treated as indicated below Water containing more than 200 ppm chlorides shall not be used Water containing more than 50 ppm but less than 200 ppm chlorides shall be treated with an inhibitor of 1.5% soda ash and 0.5% sodium nitrate. The chloride content of the soda ash and sodium nitrate shall not exceed 500 ppm Water containing 50 ppm chloride or less does not require inhibitor treatment 8.1.3.3 Piping, vessels and equipment must be drained thoroughly after testing. Where complete drainage is impossible, the system shall be flushed free of all test water using boiler condensate or de-mineralized water containing less than five (5) ppm chlorides, alcohol, petroleum distillate or another suitable flushing solution. Hot air drying is not acceptable in lieu of flushing, but water may be blown out of pockets using air.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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8.1.3.5 Piping that has been internally cleaned in accordance with NOVA Engineering Standard ESPPG-1101 Piping, Internal Cleaning Procedures shall be pressure tested after installation using a water solution containing a suitable rust inhibitor. 8.1.3.6 After piping has been pressure tested it shall be drained, cleaned and dried in accordance with NOVA Engineering Standard ES-PPG-1101 Piping, Internal Cleaning Procedures. 8.1.3.7 Alternate methods of testing piping that has been internally cleaned must have written approval from NOVA. 8.1.3.8 Piping that is to be chemically cleaned after installation shall be tested and all repairs made prior to cleaning. 8.1.3.9 To minimize the risk of brittle fracture, pressure tests through equipment shall not be conducted when the test liquid and / or metal temperature is below 59oF (15oC). Some materials may require higher test temperatures. Test temperatures shall be confirmed by NOVA Engineering prior to testing. Pressure tests in piping systems that do not include equipment shall be conducted at metal temperatures no less than as listed below: 40oF (5oC) for carbon steel 40oF (5oC) for chrome steel 40oF (5oC) for charpy (impact tested) steel 32oF (0oC) for stainless steel 8.1.3.10 The test fluid preferably shall be at temperature not exceeding 100oF (38oC). If metal temperature during test is higher than 100°F (38°C), test pressures as per the Piping Class Datasheet Pressure / Temperature Rating Table shall be prorated for the reduction in allowable stresses / flange ratings in accordance with the calculations in Section 8.2. 8.2
Test Methods and Pressures
8.2.1
Hydrostatic Testing of Piping Designed for Internal Pressure
8.2.2
The hydrostatic test pressure at any point in the system shall be as specified in the Line List and on the piping isometric drawings. Maximum test pressures for piping systems designed and fabricated to any NOVA Piping Class (refer to NOVA Engineering Guideline EG-PPG-1502 Piping, Design Guideline for Piping Class Datasheets), shall be as specified in the Piping Class Datasheet Pressure / Temperature Rating Table. Minimum test pressures shall be determined as shown below. Test pressures calculated may be lower than those specified in the Piping Class Datasheet Pressure / Temperature Rating Table due to specific combinations of design pressure and temperature. In no case shall test pressures exceed the pressure rating of any component in the system to be tested unless such components are isolated from the test pressure.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date:
18.08.1999
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 13 of 34 03 10.01.2013
8.2.2.2 Not less than 1½ times the design pressure or as calculated below. 8.2.2.3 For a design temperature above the test temperature, the minimum test pressure shall be as calculated by the following equation: PT = Where: PT = P = T
1.5*P*ST / S
minimum hydrostatic gauge pressure, psi (kPa) internal design gauge pressure, psi (kPa)
S =
allowable stress at test temperature, psi (kPa)
S =
allowable stress at design temperature, psi (kPa)
(See Table 1, Appendix A, of ASME B31.3) Note: Where ST / S is greater than 6.5, 6.5 shall be used for the value of ST / S when calculating the minimum test pressure. 8.2.2.4 Where the test pressure as defined above would produce a stress in excess of the yield strength at test temperature, the test pressure at which the stress will not exceed the yield strength at the test temperature. The maximum test pressure, at which the stress produced will not exceed the yield strength, may be calculated by the following equation: Pm =
2*Sy*t / D
Where: Pm =
Maximum Test Pressure, psi (kPa)
Sy =
Minimum Specified Yield, psi (kPa)
t
Specified Pipe Wall Thickness Minus Mill Tolerance, in (mm)
=
D =
Outside Diameter, in (mm)
8.2.2.5 If the design conditions of piping attached to a vessel are the same as those of the vessel, then the piping and vessel may be tested together at the test pressure of the vessel. See also Sections 10.1.3 and 10.1.4. 8.2.2.6 The hydro test pressure for Category ‘D’ piping is the design pressure of the system. 8.2.2.7 Underground polyethylene water lines shall not be hydro tested in the winter.
NOVA Chemicals Issue Date: 8.4
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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Hydrostatic Testing of Piping Designed for External Pressure
8.4.1.1 Lines in external pressure service shall be subject to an internal test pressure of 50 psig (345 kPa) unless otherwise specified on the line list or isometric. The individual responsible for the testing shall ensure that the line to be tested has been designed to withstand the 50 psig (345 kPa) internal test pressure. 8.4.1.2 In jacketed lines, the core pipe shall be pressure tested on the basis of the internal design pressure with minimum of 50 psig (345 kPa). This test must be performed before completion of the jacket if necessary to provide visual access to the joints of the internal line. The jacket shall be pressure tested on the basis of the internal design pressure of the jacket, but not to exceed the allowable external working pressure of the core pipe at 100oF (38oC). 8.5
Hydrostatic Test Procedure All joints, including welds, are to be left un-insulated, unpainted and exposed for examination during the test, except that the joints previously tested in accordance with this specification may be insulated or covered. If a sensitive leak test is required, all joints mentioned above shall also be left unprimed and unpainted. However, due to practical work schedule and practices, it will also be permissible that all welded joints in piping systems including butt welds and fillet welds be masked off prior to surface preparation and protective coating applications, when hydrostatic testing is to be carried out after coatings are applied. In such cases, all masking shall be removed prior to testing to facilitate leak inspection. After test all unprotected weld areas to be field touched-up with appropriate hand applied coatings.
8.5.1
Underground portions of piping systems may be tested and covered prior to testing aboveground portions.
8.5.1.1 Underground piping designed at a pressure greater than atmospheric shall be pressure tested in accordance with this Standard prior to backfilling. When portions of mechanical joint underground firewater and cooling water systems are tested before the system is backfilled, the movement of pipe must be prevented. This applies to all mechanical joint or 'push-on' joint piping designs. 8.5.1.2 Each joint shall be individually inspected and certified in accordance with the procedures set up by the supplier of the pipe prior to backfilling. 8.5.1.3 Sewer systems for use at atmospheric pressure shall be subjected to a water fill test prior to backfilling. 8.5.2
Piping designed for vapor or gas shall be provided with additional temporary supports, if necessary, to support the weight of the test liquid. Contractor shall make provisions that these lines are adequately supported.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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Lines that are counterweight supported shall be temporarily blocked during testing in order to sustain the weight of the test fluid. Spring hangers shall be provided with stops for carrying the test loads. Stops shall be installed prior to testing. If this is not the case, temporary support must be provided before filling the system. 8.5.3
Before testing: Piping systems shall have been completely checked for compliance to drawings and standards All lines, vessels and equipment shall be checked to ensure all necessary test blanks are in place and the entire system can be completely drained after testing Vents or other higher point connections shall be opened to eliminate air from lines that are to receive a hydrostatic test System shall be purged of air before hydrostatic test pressure is applied
8.5.4
All vessels and internals shall be reviewed in order to determine best method to prevent air entrapment when filling and to prevent vacuum when draining.
8.5.5
Short pieces of piping that must be removed to permit installation of a blind or blank shall be tested separately.
8.5.6
Lines containing check valves shall have the source of pressure located in the piping upstream of the check valve so that the pressure is applied under the seat. If this is not possible, remove or jack up the check valve closure mechanism or remove check valve completely and provide necessary filler piece or blinds.
8.5.7
When conducting tests at freezing temperatures the test shall not take more than four (4) hours and special precautions (such as warming the line and / or test water to a minimum temperature of 68oF (20oC) shall be observed to avoid freezing damage. Follow precautions to minimize the risk of brittle fracture as noted in Sections 8.1.3.8 and 9.5.
8.5.8
Systems that include expansion joints shall be investigated to see that any required temporary restraints, anchors, guides, etc., are installed prior to test.
8.5.9
Pressure shall be raised slowly, at approximately 100 psi/minute (690 kPa/minute), to half the final test pressure specified and held for 15 minutes to note any pressure drop or obvious leaks.
8.5.10 Proceed to raise the pressure slowly to the final test pressure, in equal steps. The number of steps shall depend on the final test pressure. Maximum step size shall be 500 psi (3450 kPa). At each step, pressure shall be held for ten (10) minutes to check for pressure drop and any weeping at flanges or joints. 8.5.11 Hydrostatic test pressure shall be held for a minimum of 30 minutes. If there has been no loss in pressure during the 30 minute period, the pressure shall be lowered to one half (½) the test pressure and the entire system visually inspected for leaks. The pressure must hold without additional pumping. If the pressure drops, this indicates a leak in the system, and the test cannot be accepted without permission of the NOVA Inspector.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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8.5.12 Leaks occurring during the raising or holding of the test pressure shall not be rectified in any way until the pressure is released back to atmospheric. In the event that repairs of any sort are required, the test procedure shall be started again from the beginning after satisfactory completion of the repairs. 8.5.13 The hydrostatic test shall not be deemed completed until witnessed and accepted by NOVA Inspector. The Regulatory Inspector may also require inspecting and accepting the test before the system may be depressured. 8.5.14 The Contractor (or NOVA, if NOVA personnel are performing the test) shall maintain a responsible person at the test site to monitor the test and equipment until such time as the NOVA Inspector has accepted the test. At no time shall the pressure be allowed to increase above the designated test pressure nor shall the system be left under pressure without any attending personnel. 8.5.15 If the NOVA Inspector has not arrived within two (2) hours’ time, the system may be depressured, but not drained, and the monitoring personnel may be dismissed. The test equipment shall remain in place until the NOVA Inspector has arrived and the system is again brought up to test pressure and the Inspector has accepted the test. 8.5.16 When a pressure test is required to be maintained for a period of time during which the testing medium in the system would be subject to thermal expansion, provision shall be made for relief of any pressure greater than the maximum test pressure. 8.5.17 In order to hydrostatic test as much piping as possible at one time, a systems test may be employed. This test shall include one or more lines and if possible connected vessels and equipment. The Contractor shall identify the extent of each system test by coding and noting the test number on a copy of the appropriate flow diagrams. Blinding and isolating locations shall also be marked on the flow diagrams. All hydro test vents and drains must be shown on the piping drawings. Vents and drains shall be plugged and seal welded after the test, in accordance with the appropriate Piping Class specification. 8.5.18 The minimum test pressure for a system test shall be such that each line in the system is subjected to a test pressure in accordance with Section 8.2. 8.5.19 The maximum system test pressure shall not exceed the pressure test rating of any piping component (See Table ‘A’) or the shop test pressure of any vessels or equipment included in the test system. (Maximum test pressures for flanges and valves conforming to ASME B16.5 are given in Table ‘A’.). Refer to the Piping Class Datasheet Pressure / Temperature Rating Table for maximum test pressures of specific NOVA Piping Classes.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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8.5.20 Systems or sections of systems to be tested may be isolated by closed valves provided the valve body and seats are suitable for the test pressure. 8.5.21 Where a suitable valve is not available, vessels, equipment or other piping not included in the system pressure test shall be either disconnected from the system or isolated by blinds or other means during the test. 8.5.22 The normal location for the pressure test gauge(s) is at grade near the pressure test pump. Readings may be made at higher points providing the gauge pressure reading plus the static head (0.036 psi/inch or 0.01 kPa/millimeter) between grade and the point of measurement does not exceed the maximum test pressure. See Paragraph 7.3 for requirements for test gauges. 8.6
Testing of Polyethylene Lines
8.6.1
The following test procedure is a guide only. The actual test procedure shall be based on a specific SDR ratio and the amount of makeup water requirement shall be specified by NOVA.
8.6.2
The testing procedure shall be as follows: Fill the line with water. Maintain flow velocity at less than two (2) feet per second at any one (1) point of the fill system Expel air completely from the line during filling and again before applying test pressure The test procedure consists of two (2) steps: The initial expansion phase and the test period. In order to accommodate the initial expansion of the pipe under test, sufficient makeup water is added to the system at hourly intervals for three (3) hours returning the piping system to the test pressure. After the completion of the initial expansion phase, [e.g.: four (4) hours after initially pressurizing the piping system under test], the actual test period shall begin. During the test period, a measured amount of makeup water should be added to return the piping system to the test pressure. The amount of makeup water SHOULD NOT EXCEED the specified limits. NOTE: Under no circumstances should the total time under test exceed eight (8) hours at the test pressure. If the test is not completed due to leakage, equipment failure or any other reason within this time period, the test section should be permitted to ‘relax’ for an additional eight (8) hour period prior to starting the next testing sequence.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date:
18.08.1999
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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9.
PNEUMATIC TESTING
9.1
General
9.1.1
The following systems may be tested pneumatically but only with the written consent of NOVA: Gas, steam or vapor lines when the weight of the hydro test liquid would overstress supporting structures or pipe wall Piping with linings subject to damage by the hydro test liquid Instrument air headers Process line for vacuum services
9.1.2
Pneumatic testing shall be carried out in accordance with the requirements of ASME B31.3.
9.1.3
All pneumatic testing shall be protected by relief valves sized to handle the maximum flow rate of the compressor or other source of pressure.
9.1.4
The Authorized Inspector with jurisdictional authority shall be notified in advance of any pneumatic testing.
9.2
Safety Procedure
9.2.1
Where a system is to be subject to a pneumatic test, it is required that a safety procedure be submitted to the local Inspector of governmental jurisdiction after review by NOVA’s Construction Safety Coordinator. Such a procedure shall indicate the area that the test covers and the provisions for preventing unauthorized persons from entering the test area. All safety precautions shall be covered to prevent injury in the event of a part of the system failing.
9.3
Test Medium
9.3.1
Nitrogen (N2) shall be used for pneumatic testing at gauge pressures above 100 psi (690 kPa). Air shall only be used for cleaned new piping at gauge pressures at 100 psig or less. For uncleaned and used pipes, only inert gases such as N2 shall be used. Note: Oil may cause an explosion above 300 psig (2070 kPa). Air may react with residues in un-cleaned used piping.
9.3.2
Instrument air headers shall be tested with dry -22oF (-30oC) or lower dew point and oil free (less than 1 ppm by weight) air. A commodity test as described in Section 15.2 may be used if the system is complete and the instrument air compressor is operational.
ENGINEERING STANDARDS
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18.08.1999
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9.4
Test Pressure
9.4.1
Minimum pneumatic test pressure shall be 1.1 times the design pressure, but not less than 5 psig (35 kPa). No factor for design temperature shall be used to increase the test pressure.
9.4.2
Maximum test pressure may be higher than the minimum specified above but not to exceed any of the following: 100 psig (690 kPa) unless the installed piping has been previously hydrostatic tested to a pressure equal to or greater than the pneumatic test pressure or the individual piping spools have been hydrostatically tested prior to erection 75% of the maximum test pressure specified in the governing valve and piping material specification 75% of the maximum test pressure of the weakest component in the test system A pressure that would produce a stress of 80% of the yield strength at test temperature (see also Section 8.2.1.3)
9.4.3
Field welds that will be subject to a pneumatic test pressure exceeding 100 psig (690 kPa) without a prior field hydrostatic test at a pressure equal to or higher than the pneumatic test pressure shall be 100% ultrasonically or radiographically examined before the pneumatic test; except that when specifically approved by NOVA, in-process examination as defined in ASME B31.3 may be substituted for ultrasonic or radiographic examination.
9.5
Test Temperature
9.5.1
The temperature (metal temperature) during a pneumatic test shall be not less than the minimum temperature of the pressure-temperature rating of the governing valve and piping material specifications plus 30oF (17oC).
9.5.2
In any case the minimum pipe metal temperature shall not be lower than those listed below unless authorized by NOVA: Material
Nominal Wall Thickness
Minimum Temperature
Carbon Steel
1½ inch (38 millimeters) and less
59oF (15oC)
Post-Heat Treated Ferritic Alloy Steels
1 inch (25 millimeters) and less
59oF (15oC)
Austenitic Steels
1½ inch (38 millimeters) and less
41oF (5oC)
NOVA Chemicals Issue Date: 9.6
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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Organization The following is provided as a suggested guideline for the minimum organization for the test.
9.6.1
Test Director This individual is responsible for all testing activities from initial location of the N 2 pumper to the final activity, let down of pressure. He / she will supervise the pre-testing and documentation of all test equipment supplied by NOVA, before each test is carried out. He / she will also witness the suppliers’ testing of their own piping prior to connection to NOVA piping. He / she is responsible for the location of manifold, test recording equipment and temporary testing lines. He / she is also responsible for designation of areas to be cordoned off in conjunction with the Safety Engineer.
9.6.2
Test Crew (pressurizing) This crew will be comprised as follows: One (1) craftsman to operate isolation valve or valves on NOVA’s equipment One (1) operator to control N2 pumper One (1) operator to open and close vent on supplier’s check valve One (1) engineer to document test, observe pressure at N2 pumpers and ensure that pressure limit as set by Test Director is not exceeded During any of the pressurizing stages between the first step soap test and the final soap test, only test crew (pressurizing) shall be allowed within the cordoned off area.
9.6.3
Test Crew (checking) This crew will be made of sufficient number of craftsmen and inspectors to soap lines, tighten joints, etc. This crew shall only be brought into the test area during the soaping operations and shall be cleared out of the area during any of the pressurizing stages.
9.6.4
Safety Engineer He / she will ensure that all procedures comply with the Safety Regulations in force on the site.
9.6.5
Quality Control Inspector He / she will ensure that all applicable codes and specifications are met prior to and during the test.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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9.7
Pneumatic Test Procedure
9.7.1
The test procedures of hydrostatic testing shall apply wherever applicable.
9.7.2
When testing at above 25 psig (175 kPa), a preliminary gas test at 25 psig (172 kPa) will be carried out to check all flanged, welded or screwed joints for major leaks and tightness. Gas introduction shall be as below.
9.7.2.1 Gas will be introduced to the system at a rate no greater than 10 psig (69 kPa) per minute (continuous). Gas shall be heated upstream of distribution manifold. Temperature monitors shall be used to detect test gas temperature. Special precautions shall be taken to ensure that liquid N2 is not introduced into distribution manifolds or test system. 9.7.2.2 The pressure shall be held for ten (10) minutes at 25 psig (175 kPa). 9.7.2.3 At the end of the ten (10) minute period, the system shall be inspected to ensure everything is in order. A soap test may be applied to all joints to detect leakage. 9.7.2.4 The pressure shall then be increased by increments of 25 psi (175 kPa) and the same procedure of inspection repeated. 9.7.3
The 25 psi (175 kPa) pressure steps shall be repeated until the final test pressure is reached.
9.7.4
The pressure supply source shall be isolated and the test pressure on the system will be held for ten (10) minutes. The pressure in the line is then reduced by manually venting the gas using the vent valve located between the double block valves.
9.7.5
A complete inspection of the pipe loop is then made including a final 'bubble' solution testing of all flanged, welded and screwed joints.
9.7.6
Pressure shall then be released without danger to personnel or damage to equipment.
9.7.7
All test blanks shall be removed. Valves and equipment that were removed for the test shall be re-installed. The line shall be checked against the drawings and cleared for operation.
9.7.8
All test data, pressure, line number and data shall be recorded by the Contractor in accordance with Section 12.
9.8
Cautionary Notes
9.8.1
No work shall be carried out on the system while pressure is above 75 psig (517 kPa).
9.8.2
All remedial work or exceptions to the system shall be so noted on the test sheet.
NOVA Chemicals Issue Date: 9.8.3
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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All NOVA testing manifolds and piping will be hydro tested to 1½ times test pressure; results will be documented and tested piping marked (fittings to be impression stamped) to indicate the pressure at which piping was tested. All N2 supplier’s piping shall be hydro tested by the supplier to 1½ times the maximum anticipated setting on the suppliers PSV. The supplier’s PSV shall also be tested to blow at set pressure each time the supplier’s truck comes on site, prior to pressurizing the system. The sequence to be followed with regard to N2 pressurization is as follows:
9.8.3.1 Subsequent to the cool down of the N2 pumper, system isolation valves to be opened before starting the pumping of N2. 9.8.3.2 On reaching desired system pressure, N2 pump to be shut down prior to closing system isolation valve, when isolation valve is closed, vent feed lines from pump to manifold. 9.8.3.3 After required waiting period, vent to be closed, system isolation valve to be opened and finally, pump to be re-started. It is very important to carry out the pressurizing steps in exactly this sequence to prevent pressure build up between the pump and the manifold. Feed lines from pump to manifold are of a relatively small volume and therefore, pressure buildup subsequent to closing system isolation valve while pumping would be very rapid and could cause a failure. 9.9
Safety
9.9.1
Nitrogen or any gas under pressure, by virtue of its compressibility, can be a highly dangerous commodity and must be treated with the greatest respect. In the event of a sudden uncontrolled release of pressure due to a failure, the forces exerted by the expanding gas can bend or fracture pipes and scatter debris in all directions. It is therefore vital, while testing using gas as the pressure medium to pay careful attention to the location of all personnel.
9.9.2
The test area, including a safety zone around all piping and equipment to be tested, shall be cordoned off with high visibility ‘caution tape’, flags, and / or other barriers deemed appropriate by the Safety Engineer. The designation of areas to be cordoned off shall be at the discretion of the Safety Engineer in conjunction with the Test Director. In no case shall the distance from the barriers to any piping or equipment subject to the test pressure be less than 500 feet (150 meters). Due regard shall be given to the intended test pressure and volume. Barriers shall be placed such that any personnel not involved with the test are kept out of the line of sight to any of the tested systems.
9.9.3
All site personnel shall be informed of the impending test and cautioned to be aware of the exclusion area.
9.9.4
The Test Crew during pressurization stages shall be kept to an absolute minimum. All other personnel shall be kept clear of the area.
9.9.5
During pressurization, all test personnel shall be located at least 100 feet (30 meters) away and out of the line of sight of any system under test.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
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9.9.6
All Test Crew shall wear hearing protection for the duration of the test.
9.9.7
All piping and equipment used for feeding N2 into lines to be tested shall be previously hydro tested and inspected by Quality Control to ensure maximum reliability.
9.9.8
N2 feed gas lines from pump to manifold shall be protected by a PSV and test personnel shall be protected from the outlet of the PSV itself.
9.9.9
Absolutely no work, i.e.: tightening glands, etc., can be done on any system containing more than 75 psig (517 kPa) of N2.
9.9.10 Under no circumstances will a test be left unattended; this applies to air as well as N2 tests, whatever the size of piping being tested. 9.9.11 Lines to be tested shall be anchored in such a fashion as to minimize damage in the event of a failure. 9.9.12 Safety permits shall be issued by NOVA Safety Coordinator prior to introduction of N2 above 25 psig (172 kPa). 9.9.13 Test feed lines from manifold to test system shall be sandbagged or secured to prevent shifting in the event of failure. 9.10
Communications
9.10.1 Test Crew (pressurizing) will wear headsets to ensure accurate and immediate communication through all phases of the test. 9.11
Equipment
9.11.1 A double block and bleed valve arrangement shall be included in the pressurizing line to the system being tested. A test pressure gauge shall be downstream of the double block. After each pressure step has been reached, close the block valves and open the bleeder to atmosphere. If after the waiting period the 'stop pressure' is held, proceed to the next 'step pressure'; if not, examine the entire system for leakage. 10.
VESSELS AND EQUIPMENT
10.1.1 The following shall be excluded from hydrostatic test: Vessels or equipment supported by other vessels or equipment or by a support structure or foundation not capable of supporting the hydro test load Vessels or equipment not capable of sustaining the hydro test load and those with internals or linings that would be damaged by the test fluid
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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10.1.2 The following shall be excluded from all pressure tests: Pumps, compressors and turbines Equipment and vendor furnished piping specifically recommended by the manufacturer not to be tested All pressure vessels already hydro tested by manufacturer to meet code requirements 10.1.3 The pressure at any point in vessels or equipment included in the pressure test shall not be greater than the shop test pressure for that equipment as stated on the vessel drawing, Vendor’s equipment drawing or specification sheets. In the event the piping test pressure is greater than the vessel or equipment test pressure, the piping shall be disconnected, blinded and tested separately. 10.1.4 If the piping cannot be disconnected (welded construction) one (1) of the following shall be implemented: The Contractor shall request written approval from the Vendor to test at the required piping test pressure Reduce piping test pressure as necessary after review and approval of the client or client’s representative. Refer to ASME B31.3 for minimum requirements 10.1.5 Heat exchangers and pressure vessels with two (2) or more pressure chambers may be designed for a low allowable differential pressure between pressure chambers, as stated on the manufacturer’s drawings. These should be checked, and if necessary, test all adjacent pressure chambers simultaneously as one (1) system with the same pressure or exclude all pressure chambers from the test. 11.
INSTRUMENTS AND CONTROL VALVES
11.1.1 All instruments and control valves shall be protected from damage when hydro testing process and utility piping systems. Table ‘B’ outlines the status of instruments during testing to insure protection. 11.1.2 Instruments not listed in Table ‘B’ shall not be subjected to the pressure test unless authorization is obtained from NOVA.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date: 12.
18.08.1999
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TEST RECORDS
12.1.1 Records shall be made for each piping system test on forms developed by each NOVA site. These forms, when completed, shall be retained in the Field QC file as a permanent record. These records shall include: Date of test Identification of piping system and any vessels or equipment tested with the piping system Test medium Test pressure Minimum ambient temperature Test medium temperature Piping registration number as required by regulatory body having jurisdiction in the area Test Certificate signed by Regulatory Inspector (e.g.: in Ontario, ‘Piping Systems Installation and Test Data Report’) 12.1.2 The calculated and maximum test pressure for each line shall be specified on the field pressure test summary. Additional data as listed below shall be provided by NOVA. 12.1.2.1 Equipment test pressures. 12.1.2.2 Test pressures of special piping components such as ball valves, butterfly valves, etc. 12.1.2.3 Special testing instructions and cautionary notes. Certification: Upon completion of the piping installation, the retained records shall include a letter of certification by the Contractor and NOVA’s inspector that all piping has been constructed and pressure tested as required by these procedures. Upon completion of the project, all records shall be sent to the Engineering office. 13.
TEST COMPLETION
13.1.1 In the event that repairs or additions are made following the pressure test, the affected piping shall be retested at the pressures originally specified for the test. Retesting of minor repairs or additions may be waived provided approval of NOVA is obtained and the welding is nondestructively examined per Section 15.1.2. 13.1.2 On completion of testing, pressure shall be released carefully. Care shall be taken to ensure there is no danger to personnel or damage to equipment. 13.1.3 Vents shall be opened before draining to prevent drawing a vacuum in the system. Care shall be exercised in controlling the rate of drainage from vessels with respect to the inflow of air through the vent, to insure that the vessel is not subjected to vacuum. A workman shall remain in attendance until draining is completed.
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18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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13.1.4 After vessels are completely drained, vents, cyclones and other internal closures that were opened prior to testing shall be closed. 13.1.5 Any specified cleaning, drying or other preparation such as sealing, ‘nitrogen padding’, etc., shall be performed in accordance with the process specifications and contract documents. Refer to NOVA Engineering Standard ES-PPG-1101 Piping, Internal Cleaning Procedures for information on cleaning requirements. Contract specifications will determine at what stage temporary blanks shall be removed and instruments, etc., installed as outlined in the paragraphs below. The order in which the system is prepared may vary depending on the intended service and when the system will be commissioned. 13.1.6 After successful pressure testing and flushing, hydrostatic vent and drain assemblies must be removed and plugs and caps installed (and back welded if specified by piping material specification). 13.1.7 All temporary blanks and blinds shall be removed, all operating blinds returned to proper position and all lines and piping components (except those tested per Section 14.2) shall be completely drained. Valves, orifice plates, expansion joints and short pieces of piping that have been removed shall be reinstalled with proper gaskets in place. All valves that were closed during hydro test shall have all vents open. Piping systems downstream of check valves should be inspected to insure complete drainage. 13.1.8 All temporary gaskets, and gaskets in any joints that are disturbed in any way after the test, e.g.: unbolted and re-bolted after the test, shall be replaced with new, unused gaskets of the proper specification for the service. Gaskets shall be in accordance with the Piping Class Datasheets and NOVA Engineering Standard ES-PPG-0702 Piping, Gaskets for Piping Flanges. 13.1.9 Direct connected transmitters at orifice flanges must be disconnected when replacing orifice plates to avoid distorting the connections. 13.1.10 Spring hangers provided with stops to carry the test loads shall have these stops removed. Stops shall be removed in accordance with the ‘Field Instructions’ provided on the individual hanger drawings. 13.1.11 Flanged joints at which test blinds have been removed shall not be retested. Special length bolting and flat asbestos gaskets shall be removed and replaced with line class bolts and gaskets. 13.1.12 Instruments that were removed or blocked out for test shall be reinstalled and blocks placed in the normal operating position.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date: 14.
18.08.1999
Piping, Pressure Testing for Piping and Equipment
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PRESSURE TEST BLINDS
14.1.1 Plain test blanks may be used for blanking flat face, raised face, ring joint, male and female, and tongue and groove type flanges. Provide full-face blanks and full face gaskets at ALL flat face flanges. Where permanent operational blinds are installed, they may be used for field pressure testing. 14.1.2 All gaskets shall be the proper specification for the intended service, in accordance with the Piping Class Datasheets and NOVA Engineering Standard ES-PPG-0702 Piping, Gaskets for Pipe Flanges. Temporary gaskets may be used at test blank locations. Temporary gaskets shall be replaced with new, unused gaskets of the proper specification when the test blanks are removed at completion of the test. Temporary gaskets shall be full face compressed material, ‘Type J’ in accordance with NOVA Engineering Standard ES-PPG-0702 Piping, Gaskets for Pipe Flanges. 14.1.3 Gaskets in any joints that are disturbed in any way after the test, e.g.: unbolted and re-bolted after the test, shall be replaced with new, unused gaskets of the proper specification. 14.1.4 Plate material, extra length bolts and gaskets for testing shall be furnished by the Contractor. See Table ‘C’ for maximum test pressures at various thicknesses. 15.
ALTERNATIVE TESTS (NOVA APPROVAL REQUIRED)
15.1
General Service
15.1.1 In circumstances when neither hydrostatic nor pneumatic tests are considered practical, an alternative test in accordance with Section 15.1.2 may be employed if both of the following conditions apply: A hydrostatic test would be damaging to linings or internal insulation: Would contaminate a process that would be hazardous, corrosive or inoperative in the presence of moisture; or would present a danger of brittle fracture from low metal temperature during test A pneumatic test would introduce considerable hazard due to possible release of stored energy in the system or would present a danger of brittle fracture from low metal temperature during test
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
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15.1.2 Under the conditions stated in Section 15.1.1, all of the following shall be applied: Welds, including those used in the manufacture of welded pipe and fittings that have not been subjected to hydrostatic or pneumatic pressure tests in accordance with this specification, shall be non-destructively examined as follows: o Butt welds shall be 100% radiographed o All welds, including structural attachment weld, shall be 100% liquid penetrant examined. If the material is magnetic, magnetic particle examination may be used in lieu of liquid penetrant examination o When heat treatment is required, the above examinations shall be performed after heat treatment The system or joints to be tested shall be subjected to a sensitive leak test. All joints that have not been hydrostatic or pneumatic tested in accordance with this specification shall be examined for leakage A flexibility analysis of the system shall be made in accordance with ASME B31.3 15.2
Commodity Test for Category 'D' Fluid Service Only
15.2.1 A piping system used only for Category ‘D’ fluid service may be tested with the service fluid at the design conditions of the system during or prior to initial operation by examining for leaks at every joint not previously hydrostatically or pneumatically tested in accordance with this specification. 15.2.2 A preliminary check shall be made at not more than 25 psi (170 kPa) gauge pressure when the contained fluid is a gas or vapor. The pressure shall be increased gradually in steps providing sufficient time to allow the piping to equalize strains during test and to check for leaks. 15.2.3 Unless dictated otherwise by contractual provision, commodity testing shall be performed by the Contractor prior to mechanical completion. 15.3
Tightness Test
15.3.1 Except for piping systems identified as Category ‘M’ Fluid Service, piping systems designed for internal gauge pressures at or above zero but less than 15 psig (100 kPa), provided the fluid handled is non-toxic and not damaging to human tissue and having a design temperature within the range of -20oF to 360oF (-29oC to 182oC) inclusive shall be tested only for tightness in accordance with one (1) of the following methods: Hydrostatic: Fill with water to the highest point in system and check all joints for leakage Pneumatic: Pressurize system to five (5) psig (35 kPa) with air or other non-flammable gas and check all joints for leakage using a bubble forming solution
ENGINEERING STANDARDS
NOVA Chemicals Issue Date: 16.
18.08.1999
Piping, Pressure Testing for Piping and Equipment
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TABLES TABLE A Maximum Hydrostatic Test Pressure for Flanges and Valves
Carbon Steel ANSI Flange Rating Classes
(1.1 – 1.4)
150 300 600 900 1500
435 1117 2234 3336 5555
150 300 600 900 1500
3.00 7.70 15.40 23.00 38.30
Material (Material Group) Carbon Moly Chrome-Moly Stainless C-½Mo ½ - ½, 1 - ½, Steel 1¼ - ½ 304, 316, 2¼ - 1 321, 347, 5 - ½ and 9 - 1 348 (1.5) (1.7 - 1.14) (2.1 - 2.5) PSIG 406 435 420 1044 1131 1087 2088 2262 2160 3132 3378 3248 5219 5625 5408 MPa (1000 kPa) 2.80 3.00 2.90 7.20 7.80 7.50 14.40 15.60 14.90 21.60 23.30 22.40 36.00 38.80 37.30
Stainless Steel 304L, 316L
(2.3) 348 913 1812 2711 4509 2.40 6.30 12.50 18.70 31.10
Notes: 1. The above chart is based on ANSI / ASME B16.5 and provides the maximum allowable hydro test pressures of NPS ½ through NPS 24 flanges and flanged end and standard class weld end valves. 2. Maximum test pressures of piping spools and systems shall be as per the Piping Class Datasheet Pressure / Temperature Rating Table for the respective Piping Class. 3. In piping systems that include valves not conforming to ASME B16.5 pressure / temperature ratings, the valves shall be removed prior to test and replaced with flanged spools. 4. Maximum test pressure for flanges and valves over NPS 24 and piping components not covered by this chart shall be determined by the Contractor as applicable. 5. The maximum test pressure for pneumatic testing shall not exceed 75% of the values listed in the table above.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date:
18.08.1999
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
Piping, Pressure Testing for Piping and Equipment
ES-PPG-1201 30 of 34 03 10.01.2013
TABLE B Status of Instruments During Pressure Test A B 1
C
D
Notes (7)
X
1, 2
X
3
X
3
Analyzers Control Valves – except regulators and pressure balanced Control Valves – pressure balanced
4
Flow Instruments – D/P Cell and Bellows Types
X
5
Flow Instruments – Rotometers
6 7
Flow Instruments – Positive Displacement Type Flow Instruments – Turbine Type
8 9
Flow Indicating Switches – Bellows Type Flow Switches – Vane Type
10
Gauge Glasses
X
11 12
Level Instruments – Displacer Type Level Instruments – D/P cell and Bellows type
X
4
13
Level Instruments – Float Type
X
4
14 15
Orifice Plates Pressure Gauges
X
16
Pressure Instruments
X
17 18 19
Pressure Regulators Pressure Switches PSV’s
2
X
X X X X
X X
5
X X X
6
20 PSV’s, TSV’s – ¾ inch and 1 inch Screwed X Column Headings and Notes: A – Block and Vent. B – Remove. C – Blind off. D – Include in Test. 1. No attempt shall be made to tighten packing to prevent leakage. 2. a. Test pressure same upstream and downstream: Leave block and bypass valves open. Control valve open or closed (whichever is most convenient) b. Test pressure different upstream and downstream: Test on upstream portion shall be made with bypass valve closed, upstream block valve open, downstream block valve closed and control valve closed. Downstream piping shall be protected from overpressure by venting, blinding or by safety relief valve 3. Caution: Do not force reverse flow 4. Caution: Do not overpressure float / displacer. If in doubt, do not test – block and drain 5. Install after hydro testing and line flushing 6. Blinds not required on PSV outlets discharging into a system being tested at 15 psig (100 kPa) or less 7. All instruments shall be protected from damage due to freezing. In preparation for cold weather and during cold weather, all instruments must be drained and process lead lines blown out with air or nitrogen.
ENGINEERING STANDARDS
NOVA Chemicals Issue Date:
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
Piping, Pressure Testing for Piping and Equipment
18.08.1999
ES-PPG-1201 31 of 34 03 10.01.2013
TABLE C Schedule of Allowable Hydrostatic Test Pressure for Various Blind Thicknesses WARNING: For TEST blinds only (Do NOT use these blind thicknesses for Process blinds or End blinds.) Min Plat e Thk inch 0.25 0.50 0.80 1.00 1.18 1.38 1.58 2.00 mm 6.5 13.0 20.0 25.0 30.0 35.0 40.0 50.0
Nominal Pipe Size (NPS) 2
3
4
6
8
2015 8090 -
928 3726 8373 -
565 2247 5060 9003 -
290 1044 2334 4154 5257 -
159 609 1377 2450 3103 4639 -
13.90 55.80 -
6.40 25.70 57.75 -
3.900 15.50 34.90 62.10 -
2.00 7.20 16.10 28.65 36.26 -
1.10 4.20 9.50 16.90 21.40 32.00 -
10
12 PSIG 101 72 391 275 884 631 1580 1116 2001 1421 2987 2117 4161 2958 4494 MPa (1000 kPa) 0.70 0.50 2.70 1.90 6.10 4.35 10.90 7.70 13.80 9.80 20.60 14.60 28.70 20.40 31.00
14
16
18
20
24
58 232 522 928 1174 1769 2450 3726
36 174 406 710 899 1348 1885 2849
145 319 565 710 1058 1479 2204
116 261 449 580 855 1203 1827
80 174 319 406 594 841 1261
0.40 1.60 3.60 6.40 8.10 12.20 16.90 25.70
0.25 1.20 2.80 4.90 6.20 9.30 13.00 19.65
1.00 2.20 3.90 4.90 7.30 10.20 15.20
0.80 1.80 3.10 4.00 5.90 8.30 12.60
0.55 1.20 2.20 2.80 4.10 5.80 8.70
Notes: 1. The Tabulated Pressures above are based on the formula stated in ASME B31.1, Paragraph 104.5.3 (B) using: a) Flat gaskets conforming to ANSI B16.21 b) Structural grade carbon steel plate, ASTM A36 having a minimum specified yield strength of 36,000 psi (5.225 ksi) 2. For plate that is identified as having a lower minimum yield strength, the allowable hydrostatic pressure must be reduced in accordance with the following formula: Pma = Yx/Y, where Pma = Maximum Allowable Test Pressure Y = Minimum Specified Yield Strength, ASTM A36 Yx = Minimum Specified Yield Strength for Material Selected 3. Pneumatic test pressures shall not exceed 75% of the values listed in the table above.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
17.
APPENDIX A – DEFINITION OF TERMS
17.1
Definitions of Standard Engineering Terms
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 32 of 34 03 10.01.2013
Code: A group of standards referring to the same topic or protocol. Criteria: All the compulsory requirements relating to the work in hand as set forth in the Engineering Standard. Discrepancy: A difference between, for example, a drawing and a written procedure. Exceptions: Irregularities; exceptions to the rule / standard, etc. Governance of Documents: The order of precedence to be taken when referring to documents governing the work referred to in this Standard. Guidelines: A document that describes the preferred way to achieve engineering objectives. Procedures: Step-by-step action plan description. Quality Assurance (QA): A guarantee made by the Supplier for the level of safety, quality and performance of their product(s) or service(s). Quality Control (QC): Primarily concerned with the procedures and processes in place to guarantee the specified product or service. References: Any materials used in the compilation of this Standard. Regulation: A law enforceable document issued originally by a government entity. Standard: A document that describes the mandatory ways to achieve engineering objectives. Variance (Major): That which has a major impact on the equipment or process design. Variance (Minor): design.
That which has very little or no impact on the equipment or process
NOVA Chemicals Issue Date: 17.2
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 33 of 34 03 10.01.2013
Definitions of Engineering Discipline Terms Bubble Test ('Soap Test'): A detection of leakage by applying bubble-forming solution (not soap) to the joints of piping system being pneumatically tested. Only commercial available solution specially manufactured for this purpose shall be used. This test shall be carried out while the line is maintained at not less than 80% of the test pressure or operating pressure whichever is the greater. Note: To detect leakage at valve stem packing and flanged joints, duct tapes may be used to tape over the leak seam with a small hole punched through the tape at the topside. Calculated Test Pressure: The test pressure determined as per Sections 8 and 9. Category D Fluid Service: (per ASME B31.3) Fluid service in which all the following apply: (1) The fluid handled is non-flammable and non-toxic; (2) The design gauge pressure does not exceed 150 psi (1030 kPa) and (3) The design temperature is between -20oF and 366oF (-29oC and 186oC). Category M Fluid Service: (per ASME B31.3) Fluid service in which exposure to very small quantities of the fluid in the environment can produce serious irreversible harm to persons on breathing or bodily contact, even when prompt restorative measures are taken. Commodity Test (Service Test): An alternative test as per Section 15.2. Damaging to Human Tissues: (per ASME B31.3) Fluid that, under expected operating conditions, can harm skin, eyes or exposed mucous membranes so that irreversible damage may be done unless prompt restorative measures are taken. (Restorative measures may include flushing with water, administrative of antidotes, medications, etc.). Hydrostatic-Pneumatic Testing: A combination hydrostatic-pneumatic test is permissible. The pneumatic test pressure shall be in accordance with Section 9.4. The pressure in the liquid-filled portion of the piping shall not exceed that given in Section 8.2.1. Test gas media shall be per Section 9.3. Hydrostatic Testing: Use of liquids in pressure tests. Maximum Test Pressure: The highest allowable test pressure gauge reading (the pressure test rating of the 'weakest' component in the test system). Minimum Test Pressure: The lowest allowable test pressure gauge reading (the calculated test pressure plus the additional pressure resulting from any static head of the test fluid above the gauge location). Pneumatic Testing: Use of gaseous fluids in pressure tests.
NOVA Chemicals Issue Date:
18.08.1999
ENGINEERING STANDARDS
Piping, Pressure Testing for Piping and Equipment
Eng. Std. #: Page No.: Rev. No.: Rev. Date:
ES-PPG-1201 34 of 34 03 10.01.2013
Regulatory Inspector: Person designated by the regulatory body having jurisdiction in the area in which the piping system is to be installed, as being authorized to inspect and accept piping installations on behalf of the regulatory body. Safety Relief Set Pressure: 100% of design pressure of the system. Sensitive Leak Test: Piping required to have a sensitive leak test shall be tested by the Gas and Bubble Formation Testing Method specified in Article 10, Section V of the ASME Code. If a hydrostatic pressure test is used, it shall be done after the sensitive leak test. Shop Testing: Testing of piping sections in the shop prior to erection (instead of testing in the field after erection). Testing medium can be either liquid or gases. Shop tests are considered when the following conditions exist: The design of the piping is such that leaks cannot be detected after installation. A typical case is jacketed piping systems The location of the installed piping is such that leaks cannot be located or repaired after installation. Typical cases are piping systems located in areas where welding is not permitted and piping systems so located that sufficient space for inspection or welding is lacking Piping systems being installed during shutdowns, where the shutdown would be extended if it were necessary to repair leaks When weather conditions make testing after installation uneconomical. A typical case is freezing weather during hydrostatic testing When spacing of supports or strength of supports would require uneconomical additional supporting of the piping system to avoid excessive bending moments during hydrostatic testing. Standard Dimension Ration (SDR): piping.
Ratio of diameter over thickness for polyethylene
Supplier: Individual or organization that furnishes items in accordance with the purchasing documents. It is a term that includes, but is not limited to, manufacturer, fabricator, contractor and sub-contractor, laboratory, consultant, vendor / distributor.
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