The Dow Chemical Company700 GS 250.50050

The Dow Chemical Company700_GS_250.50050

Gulfstream ProgramDate 30Dec2014

Page 1 of 27

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.
Revision
No. / Date / Originator's
Name & Initials / Reviewed/Checked By
Name & Initials / Pages
APPROVALS / SIGNATURES / DATE
Lead Engineer:
Project Manager:
Client Representative:
ISSUED FOR : / Design / Construction / Other

Record of Revisions

Rev. No. / Date / Description

Table of Contents

Section

1.0GENERAL

2.0PRODUCTS

3.0EXECUTION

4.0References

5.0ATTACHMENTS

1.0GENERAL

1.1Summary

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 ASMEB31.4.

6.Gas transmission and distribution piping systems under the jurisdiction of ASMEB31.8.

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 exceed150 psi (1035kPa).

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 Section3.3, 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 systemswith 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.

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.

1.2References

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

B.ASME (American Society of Mechanical Engineers)

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

C.ASME Boiler and Pressure Vessel Code

• Section VNondestructive Examination

1.3Pressure 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
• 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

1. Piping Components and subassemblies may be tested either separately or as assembled piping.
2. 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.
3. 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.

2.0PRODUCTS

2.1Temporary 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 approvedpiping 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.

2.2Temporary 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.

2.3Temporary 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.

2.4Pressure 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.

2.5Solutions

A.Corrosion Inhibitor

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

B.Soap Solution

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

3.0EXECUTION

3.1Preparation

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.

(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 section3.3G.

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 shouldbe 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.

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 Section3.3.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.

3.2Test 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 12chrome 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.

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.

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.