Specification - Gulfstream SHEgulfshe.com/gshe_doc_ctr/Master_Safety_Manual0184/700_GS... · Web...

The Dow Chemical Company 700_GS_250.50050Gulfstream Program Date 30Dec2014

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PIPING PRESSURE TESTING

This specification has been revised as indicated below and described in the revision record on the following page. Please destroy all previous revisions.

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APPROVALS SIGNATURES DATE

Lead Engineer:

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ISSUED FOR : Design Construction Other

L&EO Hydro Test Procedure This is a controlled document. No un-authorized modifications. Health, Safety, and Environmental

DOW CONFIDENTIAL – Do not share without permission


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Record of Revisions

Rev. No. Date Description




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Table of Contents

Section

1.0 GENERAL..................................................................................................4

2.0 PRODUCTS...............................................................................................7

3.0 EXECUTION.............................................................................................10

4.0 REFERENCES..........................................................................................25

5.0 ATTACHMENTS.......................................................................................25




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1.0 GENERAL

1.1 Summary

A. Scope of Specification

This specification prescribes the methods, tasks, scope, and criteria for testing installed piping systems. Any deviation from this specification requires written authorization from Dow or Designated Contractor Engineering.

B. Work Not Included

The following are excluded from the requirements of this specification:

1. Any package unit previously tested by the Manufacturer in accordance with the applicable codes.

2. Drain and sewer systems with Atmospheric design.

3. Plumbing systems, which are tested in accordance with the applicable plumbing codes.

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.

5. Liquid petroleum transportation piping systems under the jurisdiction of ASME B31.4.

6. Gas transmission and distribution piping systems under the jurisdiction of ASME B31.8.

7. Non-metallic systems, which shall be tested per manufacturer’s recommendation.

8. Existing Systems that are being re-rated.

9. Olets used for hot tap purpose.

C. Terminology

1. Category D Fluid Service (ASME B31.3): Owner’s designation for a fluid service in which all the following apply:

a. The fluid handled is nonflammable, nontoxic, and not damaging to the human tissues.

b. The design gage pressure does not exceed 150 psi (1035kPa).




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c. The design temperature is not greater than 366 degrees F (186 degrees C). The design temperature is not greater than 366 degrees F (186 degrees C).

d. The fluid temperature caused by anything other than atmospheric conditions is not less than -20 degrees F (-29 degrees C).

2. Category M Fluid Service (ASME B31.3): Owner’s designation for a fluid service in which the potential for personnel exposure is judged to be significant, and in which a single exposure to a very small quantity of a toxic fluid, caused by leakage, can produce serious irreversible harm to persons on breathing or bodily contact, even when prompt restorative measures are taken.

3. Damaging To Human Tissues (ASME B31.3): A fluid which, 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, administration of antidotes, and medication.)

4. Calculated Test Pressure: The test pressure determined in accordance with Section 3.3, of this specification.

5. Minimum Test Pressure: The lowest allowable test pressure gage reading. (calculated test pressure plus the additional pressure resulting from the static head of the test fluid.)

6. Maximum Test Pressure: The highest allowable test pressure gage reading. (pressure test rating of the weakest component in the test system.)

7. Piping system: The process or utility piping labeled with a line number on the PID’s with the same Line Class Identifier, Fluid Code, Pipe Class and process conditions.

8. Test system: A system containing several Piping systems with identical or different process design conditions, which may and can be Pressure tested together because the required test conditions are identical or within required limits

9. Test Temperature: The minimum temperature occurring during the test period of either the metal temperature of the piping being tested (including any vessels or equipment included in the test) or the test fluid temperature.

10. System Test: The testing of a Test system as defined in 1.1.C 8 above, using a single test procedure and pressure.

11. Pressure Test Blind/Spade: A circular plate with an outside diameter that matches the flange raised face outer diameter, which is trapped between two flanges for the purpose of test pressure retaining isolation. Minimum thickness as per Attachment 03. System Test: The testing of a Test system as defined in 1.1.C 8 above, using a single test procedure and pressure.




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12. Blind Flange: A machined flange without a bore to be used to close off a flanged open end by bolting to the existing flange. System Test: The testing of a Test system as defined in 1.1.C 8 above, using a single test procedure and pressure.

13. Temporary Support: A support such as a sandbag, a railway sleeper, a proprietary rated or certified lad bearing device or a structure fabricated in accordance with approved engineering fabrication drawings with specified load bearing capacity that has been designed and approved by an engineer.

1.2 References

The publications listed below form part of this specification. Each publication shall be the latest revision and addendum in effect on the date this specification is issued for construction unless noted otherwise. Except as modified by the requirements specified herein or the details of the drawings, work included in this specification shall conform to the applicable provisions of these publications.

A. API (American Petroleum Institute)

API 600 Steel Gate Valves - Flanged and Butt-Welding Ends API 602 Compact Steel Gate Values

B. ASME (American Society of Mechanical Engineers)

ASME B16.5 Pipe Flanges and Flanged Fittings ASME B16.21 Nonmetallic Flat Gaskets for Pipe Flanges ASME B16.34 Valves - Flanged, Threaded, and Welded End ASME B31.1 Power Piping ASME PCC-2 Repair of Pressure Equipment and Piping

C. ASME Boiler and Pressure Vessel Code

Section V Nondestructive Examination

1.3 Pressure Testing

A. The pressure test shall be performed after the completion of all required examination and before the internal cleaning of the pipe.

B. The calculated test pressure for each line shall be specified in the Pipe Line List. Additional data, as listed below, shall be provided by Dow or designated Contractor Piping Engineering:

Equipment test pressures




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Test pressures of special piping components such as ball valves and butterfly valves

Special testing instructions and cautionary notes

1.4 Special Provisions for Testing

A. Piping Components and subassemblies may be tested either separately or as assembled piping.

B. Flanged joints used to connect piping components and subassemblies that have previously been tested, and flanged joints at which a blank or blind used to isolate equipment or other piping during a test, need not be leak tested.

C. Closure welds. The final weld connecting piping systems or components which have been successfully leak tested, need not be leak tested provided the weld is examined i-process and passes with 100% radiographic examination or 100% ultrasonic examination.




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2.0 PRODUCTS

2.1 Temporary Welded End Closures

A. The use of plate for temporary welded on end closures is not allowed.

B. Materials used for welded on end closures such as caps or blinded flanges must be per project approved piping material (line class) specifications. Project approved welding procedures and welding requirements must be adhered to. Exceptions or deviations to the approved specifications must be approved by the home office piping engineer.

2.2 Temporary Non Welded End Closures

When required, non welded temporary end closures, such as test plugs, must be selected and used per manufacturer’s recommendations and requirements.

2.3 Temporary spool pieces

Where in-line instruments or valves have to be removed during the test, temporary spool pieces may have to be provided with temporary gaskets and bolting. Spool pieces shall be able to withstand the intended test pressure and be fabricated of material per approved piping material specifications.

2.4 Pressure Test Blinds

A. Plain test blanks with 1/16 of an inch flat non-asbestos full face or ring type gaskets shall be used for blanking flat face, raised face, male and female, and tongue and groove type flanges. Provide full face blanks and gaskets at 125# CI connections. However, where permanent operational blinds are installed, they may be used for field pressure testing. (Listed material should be used for this purpose.)

B. A field procedure must be established and care taken to ensure the installation and removal of material specified for testing. The following is one method for identifying test material:

Plate material, extra length bolts, and gaskets for testing shall be furnished by the field unless dictated otherwise by contract requirements. The outer periphery (edge) of each test gasket shall be dabbed with a spot of fluorescent yellow paint in 4 spots (90 degree equidistant) prior to installation. End points of studs and heads of bolts shall be dabbed with a spot of fluorescent yellow paint. Refer to Attachment 03 for maximum test pressures at various blank thicknesses.

2.5 Solutions

A. Corrosion Inhibitor

A suitable non-toxic rust inhibitor for hydrotesting of clean lines, and / or harden inhibitor in lines with stainless steel components.




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B. Soap Solution

A suitable soap solution for determining leaks during the pneumatic testing of systems.




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3.0 EXECUTION

3.1 Preparation

A. General

1. Prior to initial operation, all installed piping shall be pressure tested except where otherwise qualified in this specification.

2. The test shall be hydrostatic using water unless 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. Testing of ferritic piping, however, is limited to the temperature restrictions in Section 3.6C, of this specification.

a. If a flammable liquid is used, its flash point shall be no less than 120 degrees F and consideration shall be given to the test environment.

b. If testing with glycol water mixtures to prevent freezing, the disposal problem of the test fluid shall be considered.

c. The volume of water required for the pressure test, must be addressed during the preparation for the pressure test.

3. The following systems may be tested pneumatically (with authorization from the Owner of the installation).

a. The weight of the hydrotest liquid would overstress supporting structures or pipe wall in a gas, steam, or vapor lines.

b. Lined pipe that could be damaged by the hydrotest liquid.

c. The instrument air headers shall be tested with dry air. A commodity test as described in Section 3.3.G of this specification and paragraph 4 below, may be used if it is Category D Fluid Service, the system is complete and the instrument air compressor is operational.

d. The process or piping material would be adversely affected by water.

4. In circumstances when neither hydrostatic nor pneumatic tests are considered practical, an alternative test per section 3.3H may be employed, subject to Owner and Construction Authorization and if all of the following applies:

a. A hydrostatic test would do the following:

(1) Damage linings or internal insulation.L&EO Hydro Test Procedure This is a controlled document. No un-authorized modifications. Health, Safety, and Environmental



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(2) Contaminate a process which would be hazardous, corrosive, or inoperative in the presence of moisture.

(3) Require significant support modifications for the hydrostatic test load.

(4) Present a danger of brittle fracture from low metal temperature during test.

b. A pneumatic test would do the following:

(1) Introduce considerable hazard due to possible release of stored energy in the system

(2) Present a danger of brittle fracture from low metal temperature during test.

5. For aboveground Fluid Category D piping an Initial Service Leak Test (Commodity Test) may be performed if approved by the Owner. See also section 3.3G.

6. Piping identified as Category M Fluid Service shall, in addition to the Hydrostatic Leak test or Pneumatic test, be subjected to a sensitive leak test in accordance with Section 3.3H., of this specification.

7. Where it is required, additional testing procedures shall be prepared for testing in the range of 350 to 3,500 Barg (5000 to 50,000 psi) to supplement this specification.

8. Calculation of safety distance for pressure testing should be addressed. See paragraph 3.5.w.

B. Vessels and Equipment

1. The following shall be excluded from hydrostatic tests:

a. Vessels or equipment supported by other vessels or equipment or by a support structure or foundation, not capable of supporting the hydrotest load.

b. Vessels or equipment not capable of sustaining the hydrotest load, and those with internals or linings that would be damaged by the test fluid.

2. The following shall be excluded from all pressure tests:

a. Pumps, compressors, and turbines.

b. Equipment and Supplier furnished piping specifically recommended by the Manufacturer not to be tested.




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3. The pressure on 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, Supplier's equipment drawing, or datasheets. 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. If the piping cannot be disconnected (welded connection), 1 of the following shall be implemented:

a. The appropriate Mechanical Equipment Engineer shall request written approval from the Supplier to test at the required piping test pressure. Refer to Section 3.3.A.3, of this specification.

b. Reduce piping test pressure as necessary after review and approval of the Owner. Refer to Section 3.3.A.4, of this specification.

4. Certain types of exchangers are specifically designed for a low allowable differential pressure between shell and tubes, as stated on the Supplier drawings and datasheets. These should be checked; and, if necessary, test both shell and tubes simultaneously as one system, with the same pressure or exclude both sides from the test.

5. Pressure vessels with 2 or more pressure chambers are specifically designed for a low allowable differential pressure between pressure chambers as stated on the Manufacturers' drawings. These should be checked; and if necessary, test all adjacent pressure chambers simultaneously as one system, with the same pressure or exclude all pressure chambers from the test.

C. Instruments

Instruments shall be protected from damage when hydrotesting process and utility piping systems. Attachment 02 outlines the status of instruments during testing to ensure protection.

3.2 Test Medium Criteria

A. Care shall be taken to ensure the use of clean water for these tests. A suitable filter should be provided in the filling line, should foreign matter such as sand, rust, or other particles be in evidence in the proposed test water. The use of seawater is prohibited.

B. Water used for hydrostatic testing of austenitic stainless steel piping, vessels, and equipment including those with austenitic stainless steel claddings, linings, or internals shall be tested for chlorides and MIC (Microbiologically Influenced Corrosion Causing Bacteria) and shall conform to the requirements listed below. These requirements also apply to 12 chrome claddings or linings that are welded with austenitic stainless steel weld filler, as well as, medium and high nickel alloys and ferritic chromium stainless steel where pitting corrosion is a risk.

1. Water containing more than 200 ppm (Parts Per Million) chlorides shall not be used.




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2. Water containing more than 50 ppm but less than 200 ppm chlorides shall be treated with an inhibitor of 1.5 percent soda ash and 0.5 percent sodium nitrate. The chloride content of the soda ash and sodium nitrate shall not exceed 500 ppm. These percentages are by weight. Systems containing water with up to 200 ppm chlorides should be flushed with condensate or demineralized water immediately after testing.

3. Water containing fewer than 50 ppm chloride does not require chloride inhibitor treatment.

4. Steam Condensate and Demineralized water that meet the requirements of 3.2B.3. is preferred water.

5. All water sources need to be tested for MIC (Microbiologically Influenced Corrosion Causing Bacteria) by an accredited Biological Testing Laboratory. If MIC is detected, contact Home Office Mechanical Engineering Metallurgist for proper steps to eliminate the bacteria prior to use. The bacteria analysis from the lab is required for proper diagnosis.

6. Piping, vessels, and equipment must be drained thoroughly after testing. Where complete drainage is impossible, when other than demineralized water or steam condensate has been used, the system shall be flushed free of all test water using boiler condensate or demineralized water containing 200 ppm hydrogen peroxide with less than 1 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 instrument air or other dust filtered air.

7. It should be noted that risk of pitting corrosion is considerably diminished if the time between pressure testing and startup is as short as possible. When other than steam condensate or demineralized water has been used and the time is anticipated to be longer than five (5) days, flushing with condensate or demineralized water containing 200 ppm hydrogen peroxide is recommended.




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C. Piping that has been internally cleaned by sandblasting shall be tested after installation using a water solution containing a suitable rust inhibitor. After piping has been tested, it shall be drained and blown dry with air or nitrogen. A suitable corrosion inhibitor not objectionable to process stream shall be used.

D. Piping that is to be chemically cleaned after installation shall be tested and all repairs made prior to cleaning.

E. Systems that will be pneumatically tested because the pipeline in service will contain hydrogen cyanide or similar services contaminated by water shall be tested as follows:

1. Testing shall be performed using filtered, non-lubricated dry air only. Air provided directly from the plant compressor shall not be acceptable. Bottled dry compressed air or dry nitrogen may be used as an alternative.

Note!!! Under no circumstances shall water be used in pressure testing of the system.

2. Unidirectional valves that are supplied with vent holes should be tested so the vent hole shall be located toward the upstream (high pressure) end when the plug is in the closed position.

3. After final test, all valves shall be wiped clean once more with clean, lint free rags and trichloromethane solvent. This cleaning shall include all accessible surfaces. Do not submerge the valve in the solvent. No trace of trichloromethane must remain or be trapped inside the valve.

F. Environmental Management: All Requirements dealing with any environmental matter directly concerned with hydrotesting, shall be complied with during the preparation and actual testing. These requirements can be as a result of legislation, environmental impact studies or assessments that were conducted or from Record of Decision (ROD) that may have been issued by any Government Department concerned with each project.

3.3 Test Methods and Pressures For ASME B31.3 Piping Systems

A. Hydrostatic Testing of Piping Designed for Internal Pressure

1. The hydrostatic test pressure at every point in the system shall be as follows:

a. When the design temperature is greater than the test temperature, the minimum test pressure, at the point under consideration, shall be calculated by Equation 1. When the piping system contains more than one material or more than one design temperature, Equation 1 shall be used for every combination, excluding pipe supporting elements and bolting, and the maximum calculated value of Pt is the minimum test gage pressure.




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Pt = 1.5 PRr Equation 1

Pt = Minimum test gage pressure P = Internal design gage pressureRr = ratio of St/S for pipe or components without established ratings, but

shall not exceed 6.5= ratio of the component pressure rating at the test temperature to the

component pressure rating at the component design temperature for components with established ratings, but shall not exceed 6.5.St = Allowable stress at test temperature S = Allowable stress value at component design temperature (Refer to

Table 1, A-1, ASME B31.3)

2. Where the test pressure as defined above would produce a stress in excess of the yield strength at test temperature or a pressure more than 1.5 times the component rating at test temperature, the test pressure shall be reduced to the maximum pressure that will not exceed the lesser of the yield strength (Equation 2) or 1.5 times the component ratings at test temperature.

Pm=2YTD Equation 2

Pm = Maximum Test Pressure (psig)Y = Minimum Specified Yield Strength (psi)T = Specified Pipe Wall Thickness Minus Mill Tolerance (in)D = Outside Diameter (in)

3. If the design conditions of piping attached to a vessel are the same as those of the vessel, the piping and vessel may be tested together at the test pressure of the vessel. However, if the piping may be subject to higher design conditions; if it requires a higher test than the connected equipment; or if the piping is designed for lesser operating conditions than the connected equipment and could be overstressed by a system test, it shall be isolated and tested separately.

4. Where the test pressure of the piping exceeds the vessel test pressure and it is not considered practical to isolate the piping from the vessel, the piping and the vessel may be tested together at the vessel test pressure, provided the Owner approves and the vessel test pressure is not less than 77 percent of the piping test pressure calculated in accordance with Equation 1.




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B. Hydrostatic Testing of Piping Designed for External Pressure

1. Lines in external pressure service shall be subjected to an internal test pressure of 1-1/2 times the external differential design pressure but no less than a gage pressure of 15 psi.

2. In jacketed lines, the internal line shall be pressure tested on the basis of the internal or external design pressure, whichever is more critical. This test must be performed before completion of the jacket to provide visual access to the joints of the internal line.

3. The jacket shall be pressure tested on the basis of the jacket design pressure. Care must be taken to prevent damage to the internal line when testing the jacket.

C. Pneumatic Testing

If the piping is tested pneumatically, the test pressure shall be 110 percent of the design pressure. The test procedure shall be in accordance with section 3.7 of this specification.

D. Hydrostatic-Pneumatic Testing

A combination hydrostatic-pneumatic test is permissible. The pneumatic test pressure shall be in accordance with Section 3.3.F, of this specification. The pressure in the liquid filled portion of the piping shall not exceed that given in Section 3.3.A, of this specification.

E. 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. Sensitive leak test shall be performed after hydrostatic test.

F. Tightness Test

1. Except for piping systems identified as Category M Fluid Service, piping systems designed for internal gage pressures at or above 0 but less than 15 psig shall be tested for tightness in accordance with one of the following methods:

a. Hydrostatic

Fill with water to highest point in system and check all joints for leakage. See Attachment 04 - Hydro Test Connection Diagram.

b. Pneumatic

Pressurize system to 5 psi with air or other nonflammable gas and check all joints for leakage using a bubble forming solution. See Attachment 05 – Pneumatic Test Connection Diagram.




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2. The fluid handled shall be nontoxic and not damaging to human tissue and have a design temperature within the range of minus 20 degrees F to 366 degrees F, inclusive.

G. Initial Service Leak Test for Category D Fluid Service Only (ASME B31.3)

1. A piping system used only for Category D Fluid Service, not previously hydrostatic or pneumatic tested in accordance with this specification, may be tested at the normal operation conditions of the system during or prior to initial operation by examining for leaks at every joint. Commodity testing shall require Owner's authorization.

2. A preliminary check shall be made at no more than 25 psig 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 and to check leaks.

H. Alternative Tests (Owner Approval is Required) in services other than Category D Fluid Service

Under the conditions stated in Section 3.1A.4, of this specification, the following Alternate Leak Test shall be applied:

1. Welds, including those welds used in the manufacture of welding pipe and fittings, which have not been subjected to hydrostatic or pneumatic leak tests in accordance with this specification shall be nondestructively examined as follows:

a. Butt welds shall be 100 percent radiographed or 100 percent ultrasonically examined.

b. All welds, including structural attachment welds, not covered in (a) above, shall be liquid penetrant examined. If the material is magnetic, magnetic particle examination may be used in lieu of liquid penetrant examination.

c. When heat treatment is required, the above examinations shall be performed after heat treatment.

2. The system or joints to be tested shall be subjected to a sensitive leak test in accordance with Section 3.3.E, of this specification. Joints that have not been hydrostatic or pneumatic tested in accordance with this specification shall be examined for leakage.

3. A flexibility analysis of the piping system shall have been made in accordance with the requirements of ASME B31.3.




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3.4 Test Methods And Pressures For ASME B31.1 Piping Systems

A. Hydrostatic Testing of Boiler External Piping (ASME B31.1)

Boiler external piping shall be hydrostatically tested in accordance with PG-99, Section 1, of the ASME Boiler and Pressure Vessel Code. The test shall be conducted in the presence of the authorized inspector.

B. Hydrostatic Testing of Non-boiler External Piping

1. The hydrostatic test pressure at every point in the piping system shall be no less than 1-1/2 times the design pressure. The minimum test pressure shall be as calculated by the following equation:

Pt=1. 5P Equation 3Pt = Minimum hydrostatic gage pressure (psi)P = Internal design gage pressure (psi)

2. At no time during the pressure test shall any part of the piping system be subjected to a stress greater than 90 percent of its yield strength (0.2 percent offset) at test temperature.

3. The maximum test pressure at which the stress produced in the piping shall not exceed 90 percent of the yield strength of the piping material at test temperature shall be calculated by the following equation:

Pm=2(0.9Y )T

DEquation 4

Pm = Maximum test pressure (psig)0.9Y = 90 percent of the minimum specified yield strength of the piping material (0.2 percent offset).T = Specified pipe wall thickness minus mill tolerance (in.)D = Outside diameter (in.)

C. Pneumatic Testing

The pneumatic test pressure shall be no less than 120 percent or more than 150 percent times the design pressure of the piping system.

D. Initial Service Test

1. When authorized by the Owner, an initial service test and examination is acceptable when other types of tests are not practical or when leak tightness is demonstrable due to the nature of the service.




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2. When performing an initial service test, the piping system shall be brought up to normal operating pressure and continuously held for 10 minutes minimum. The piping system shall show no visual evidence of weeping or leaking.

3.5 Test Preparation - Field Procedure

A. Joints, including welds, shall be left non-insulated and exposed for examination during the test, except that joints previously tested in accordance with this specification may be insulated or covered. If a sensitive leak test is required (according to Section 3.3H., of this specification), all joints mentioned above also shall be left unprimed and unpainted.

B. Underground portions of piping systems may be tested and covered before testing aboveground portions.

C. Piping designed for vapor or gas shall be provided with additional temporary supports, if necessary to support the weight of the test liquid. Where it is required, temporary supports shall be specified in the pressure test documents.

D. Lines that are counterweight supported shall be temporarily blocked during testing in order to sustain the weight of the test fluid. Spring hangers that have been provided with stops for carrying the test load normally do not require additional temporary supports; if this is not the case, temporary support must be provided before filling the system.

E. Before testing, the following procedures shall be carried out:

1. Verify that any required heat treatment has been performed.

2. Piping systems shall have been completely checked (punched out).

3. Lines, vessels, and equipment shall be checked to ensure that the entire system can be completely drained after testing.

4. Vents or other high point connections shall be opened to eliminate air from lines that are to receive a hydrostatic test. All air shall be vented prior to start of the pressure test.

5. System shall be purged of air before hydrostatic test pressure is applied.

F. Field personnel shall review all vessels and internals in order to determine best method to prevent air entrapment when filling and to prevent vacuum when draining.

G. Short pieces of piping that must be removed to permit installation of a blind or blank shall be tested separately.

H. Flanged joints at which a blank is inserted to isolate other equipment during a test need not be tested after blank is removed.




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I. 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.

J. When conducting tests at freezing temperatures, the test shall not take more than 4 hours, and special precautions such as warming the line test water shall be observed to avoid freezing damage. Follow precautions to minimize the risk of brittle fracture as noted in Section 3.6.G, of this specification.

K. Systems that include expansion joints shall be investigated to refer to that any required temporary restraints, anchors, or guides are installed or removed prior to test.

L. 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.

M. Where it is possible, systems or sections shall be tested at a flanged isolation using a blind flange or hydrostatic test blind. For required thickness of Test Blanks see Attachment 03.

N. Where a suitable flanged isolation 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.

O. Rising stem values shall be fully opened and back seated. Although not recommended, Piping, or sections of piping, to be tested may be isolated by closed valves in exceptional cases and only provided the valve closure is suitable for the test pressure.

P. Unidirectional valves that are supplied with vent holes should be tested so the vent hole shall be located toward the upstream (high pressure) end when the plug is in the closed position.

Q. All components which might be damaged by the test pressure, such as traps, instruments, diaphragm valves, relief valves, pumps, vessels, etc, shall be blanked or removed from the Piping systems. For welded-in control valves their internals have to be removed and stored carefully. Valves and other in-line piping components for which the operating temperature is below 0 degrees C shall be removed prior to hydrostatic test, unless drying out can be properly achieved. Test pumps shall be disconnected from the test system prior to line inspection. All piping shall be thoroughly cleaned by flushing with water, or by blowing out with air or steam, if pneumatically tested. It shall be verified if all lines, vessels and equipment can be completely drained after testing.

R. Vessels, heat exchangers and equipment, which have to be excluded from pressure testing, shall be physically disconnected and, unless otherwise stated, flushing with water shall not be done through these items. If there is a need to pressure test through equipment with 2 or more pressure chambers (e.g. welded-in heat exchanger) special care is required for allowable




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differential pressure between pressure chambers as stated on the Manufacturers' drawings. If necessary, test all adjacent pressure chambers simultaneously as one system with the same pressure or exclude all pressure chambers from the test. This applies also for de-pressurizing the system after test completion. For these specific pressure tests a field procedure shall be prepared and is subject to approval by Construction.

S. In cases where a pipe line being tested extends beyond the battery limit without flanges, it shall be tested to the first block valve or set of flanges outside the battery limit. Care shall be taken to see that lines beyond limits are tested in accordance with pressure specified on Offsite Field Pressure Test Flow Diagrams.

T. Piping which connects to, or is continuous with, piping installed by others shall be isolated from these lines by pipe test blanks or blinds during pressure testing and flushing. Where it is necessary to include portions of such lines in the test, testing shall be performed up to the first possible blinds and test blanks in the system provided by others.

U. The normal locations for the pressure test gage are at grade near the pressure test pump. Readings may be made at higher points providing the gage pressure reading and the static head (0.433 psi/ft) between grade and the point of measurement do not exceed the maximum test pressure. Gages shall be tagged with the date last calibrated, and this activity shall be recorded. Gauge pressure line must be separate from pressure fill line.

V. 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 to vessels and equipment. Pressure test P&ID’s shall be developed for identifying test packages. Test packages shall be by Test Systems / circuits.

W. Barricading and Accessing to Testing Area

1. Prior to a pressure testing taking place, the surrounding area must be barricaded off and clearly demarcated as a danger zone. These measures shall stay in place until the pressure test is completed. The barricades shall maintain a safe distance from the items being tested.

2. Pneumatic leak test consideration should be given to the risk associated with the release of stored energy and to the establishment of the minimum safe distance between personnel and the equipment being tested. Equations and considerations are available in the ASME PCC-2, Article 5.1.




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3.6 Hydrostatic Test Procedure

A. 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 3.3, of this specification.

B. The maximum system test pressure shall not exceed the pressure test rating of any piping component, 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 and ASME B16.34 are given in Attachment 01.

C. Hydrostatic test pressure shall not be applied until the vessel or equipment and its contents are at approximately the same temperature. To minimize the risk of brittle fracture, pressure tests through vessels and equipment shall not be conducted when the test liquid or metal temperature is below 60 degrees F (16 degrees C). Pressure tests in ferritic piping systems that do not include vessels or equipment may be conducted below 60 degrees F but shall not be conducted when the test liquid or metal temperature is below 40 degrees F (5 degrees C).

D. Hydrostatic test pressure shall be maintained for a sufficient length of time to visually determine whether there are any leaks, but no less than 10 minutes. Contractor is not required to maintain test pressure in excess of 2 hours after notification of the Owner's authorized inspector.




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3.7 Pneumatic Test Procedure

A. Minimum Metal Temperature

At time of testing, the minimum pipe metal temperature shall be as listed below:

Minimum Temperature Nominal Wall Thickness

60 degrees F (16 degrees C) Carbon steel 1-1/2 inches and less60 degrees F (16 degrees C) Post heat treated ferritic 1 inch and less

40 degrees F (5 degrees C) Austenitic steels 1 inch and less

Note: Minimum temperatures for materials not listed above shall be determined by Piping Engineering when required by field construction.

B. Clear the test area before bringing the line up to test pressure. It may be desirable to conduct pneumatic tests during weekends when fewer personnel are present.

C. A pressure relief device shall be provided, having a set pressure no higher than the test pressure plus the lesser of 50 psi or 10 percent of the test pressure.

D. When pneumatic testing at over 15 psig, a preliminary check at 15 psig shall be made to locate major leaks. The pressure shall be increased in gradual steps of 5 psig or 10 percent of the test pressure, whichever is greater.

E. For flanged joint testing during pneumatic testing, the flange joint shall be hermetically sealed by means of adhesive paper tape, and a pin hole made in the tape, to permit easy detection of leaks.

F. When the system has been brought up to the test overload shown on the piping pressure test system record, the pressure shall then be reduced to the design pressure before being examined for leakage. Joints and welds shall be covered with soap solution in order to detect any leakage. Soap shall be a commercial preparation made specifically for leak detection.

G. Before soaping the joints, the entire line should be walked to determine whether there is any audible evidence of leakage. Any leaks found at the time shall be marked and repaired after first depressurizing the line. Sizeable leaks will be noticeable prior to walking.

H. Bolting shall not be tightened while systems being tested are pressured above 30 psig.




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I. Pneumatic test pressure shall be maintained for a sufficient length of time to permit thorough visual inspection of all joint and weld seams but no less than 10 minutes. The contractor is not required to maintain test pressure in excess of 2 hours after notification of Owner's authorized inspector. Pressure shall be reduced gradually when depressurizing. Air form lines of pneumatic systems, can present hazards to operators and others. To reduce noise an air silencer can be installed. See Attachment 05.

3.8 Sensitive Leak Test Procedure

For the Sensitive Leak Test, reference is made to ASME B31.3 para. 345.8(b)

3.9 Tightness test Procedure

For tightness testing the system shall be filled with water or pressurized with air or other nonflammable gas and then all joints are to be checked for leaks. When testing with air or gas the joints shall be checked using a bubble forming solution.

3.10 Initial Service Leak Test Procedure

For the Initial Service Leak Test the test pressure shall be applied in increments of approx. 20% allowing time between increments for the piping system to equalize strains and to observe the leaks. However, for compressed gas systems the initial increment shall not exceed 170 kPag. Application of the test fluid to the piping system shall be through a valve opened slightly to minimize damage in the event of a piping failure. The pressure shall be maintained for sufficient time to determine if there are any leaks but not less than 10 minutes. Release pressure, repair any leaks, and retest.

3.11 Test Records

A. Records shall be made of each piping system test utilizing Template 000.509.F75201, Pressure Test Report. Forms, when completed, shall be retained in the Field QC file as a permanent record. These records shall include the following information:

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 Certification by examiner Test results Name of test operator Minimum metal temperature (if applicable)

B. Upon completion of the piping installation, the only retained records shall be a letter of certification by Owner's authorized inspector that all piping has been pressure tested as required




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by these procedures. Upon completion of the project, these records may be sent to the home office as specified in the Job Closeout Procedure.

3.12 Test Completion

A. Pressure tests are successful if no leaks, no cracks and no deformations are detected. If leaks are found, their location shall be marked the pressure shall be gradually released, and the piping shall be drained or vented. All vents have to be opened and kept open in order that no vacuum is generated. Huge amounts of water have to be drained directly to sewer inlet (e.g. by hose) in order not to flood ground.

B. If leaks are found on flanged, threaded, plugged or welded joints, the system pressure shall be totally released prior to any rectification work starting appropriate repair or replacement shall be made. The affected piping shall be re-tested at the pressures originally specified for the test. Re-testing of minor repairs or additions may be waived, provided approval of Owner is obtained and the welding is nondestructively examined according to Section 3.4.A.2, of this specification.

C. After completion of testing the system shall be cleaned / flushed, all temporary blanks and blinds shall be removed, all operating blinds returned to proper position, and all lines and piping components (except those tested according to Section 3.4B., of this specification) shall be completely drained. Valves, orifice plates, expansion joints, and short pieces of piping that have been removed shall be reinstalled with proper new gaskets in place. Valves that were closed during hydrotest shall be opened to ensure drainage of the bonnet cavity. Lines being drained after testing and cleaning shall have all vents open. Piping systems downstream of check valves should be inspected to ensure complete drainage. Piping containing soft-seat valves shall be flushed and drained before the valves are installed.

D. Direct connected transmitters at orifice flanges must be disconnected when replacing orifice plates to avoid distorting the connections.

E. Care shall be exercised in controlling the rate of drainage from vessels with respect to the inflow of air through the vent to ensure that the vessel is not subjected to vacuum. After vessels have been completely drained, vents, cyclones, and other internal closures that were opened before testing shall be closed.

F. After lines have been drained, temporary supports shall be removed, and insulation and painting completed. Spring hangers provided with stops to carry the test load shall have these stops removed.

G. Flanged joints at which test blinds have been removed need not be retested.

H. General

1. Instruments which were removed or blocked out for test shall be reinstalled and blocks placed in the normal operating position.




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2. Bolting and gaskets used for pressure testing shall be removed and replaced with bolts and gaskets specified in the Line Class.

3. Gaskets used for pressure testing shall be removed and replaced with line class gaskets.

4. Check valves that were jacked open or the internals were removed for pressure testing shall be returned to their proper operating position.

5. Vessel and equipment internal closures which were opened specifically for pressure testing shall be closed.

6. Instruments and process lead lines that were subjected to the hydrostatic pressure test shall be blown out with dry air or nitrogen.

7. Vent and drain connections that were added solely for pressure testing shall be closed and seal welded as required. Drains shall have either the valve closed and plugged or, if the valve is removed, the connection plugged and seal welded as required.

8. Painting and insulation shall be completed after inspection of seal welded vents & drains.

9. Strainer screens that were be removed, prior to testing can be re-installed after testing, drawing, drying, etc., have been completed and system is ready for final reinstating and punched for start-up.

4.0 REFERENCES

ConstructionTemplate 000.509.F75201: Pressure Test Report (Contained in Practice 000.509.0000, Site Quality

Manual (SQM))

5.0 ATTACHMENTS

Attachment 01 Maximum Hydrostatic Test Pressure (Barg) for Flanges and Valves

Attachment 02 Status of Instruments during Pressure Test

Attachment 03 Schedule of Maximum Allowable Hydrostatic Test Pressures for the Listed Test Blind Thicknesses

Attachment 04 Hydro Test Connection Diagram

Attachment 05 Pneumatic Test Connection Diagram




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End of Specification



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