Testing Prosedure Gate Valve

TESTING PROCEDURE FOR GATE VALVE 

 1.0 Purpose 

The purpose of this procedure is to maintain a system which identifies and plans the method, acceptance criteria and responsibilities to perform Pressure Testing of Valves 

 2.0 Scope 

This procedure covers Pressure Testing of Gate Valve. Every valve is to be hydrostatic shell pressure tested to ensure the pressure integrity of valve body. The valve seat is also checked to verify that leakage pass the API Standard 598/6D and customer requirements. 

 3.0 Definitions 

3.1 Product : Result of a set interrelated or interacting activities which transforms inputs into outputs. 3.2 Record Document : Stating results achieved or providing evidence of activities performed. 3.3 Inspection : Conformity evaluation by observation and judgment accompanied as appropriate by measurement, testing or gauging. 

3.4 Bidirectional Valve : Valve designed for blocking the fluid in both downstream and up steam directions. 

3.5 Block Valve : Gate, plug or ball valve that blocks flow into the downstream conduit when in the closed position. 

3.6 Double-Block & Bleed : Valve with two seating surfaces which, in the closed position, blocks flow from both valve ends when the cavity between the seating surfaces is vented through a bleed connection provided on the body cavity. 

3.7 Obturator / Closure Member : Part of valve, such as a ball, clapper, disc, gate or plug, which is positioned in the flow stream to permit or block flow. 

3.8 Pressure Containing : Parts, such as bodies, bonnets, glands, stems, gaskets and bolting, designed to contain the pipeline fluid. 

3.9 Test Pressure : Internal pressure, expressed in psi or Mpa or Kg/cm2, to which the valve under test is subjected. 

3.10 Test Fluid : At the discretion of the manufacturer, either 3.11 or 3.12. 

3.11 Liquid : Water which may contain a corrosion inhibitor, kerosene, or other valve under test is subjected. 

3.12 Gas : Air or suitable gas. 

 4.0 Reference Documents 

 4.1 API Standard 598 : Valve Inspection and Test 

4.2 API Standard 600 : Steel Gate Valves - Flanged and Butt-Welding Ends, Bolted and Pressur Seal Bonnets

 4.3 API Standard 602: Compact Steel Gate Valves - Flanged, Threaded, Welding, and Extende Body Ends 

4.4 ASME B16.34 : Valves - Flanged, Threaded, and Welding Ends 

4.5 ASME B16.5 : Pipe Flanges and Flanged Fittings--NPS 1/2 through NPS 24 

4.6 ASME B16.47 : Larger Diameter Steel Flanges--NPS 26 through NPS 60 

4.7 ASME B1.20.1 : Pipe Threads, General Purpose (Inch) 

4.8 ASME B16.11 : Forged Steel Fitting, Socket-Welding and Threaded 

4.9 MSS SP-44 : Steel Pipelines Flanges 

4.10 MSS SP-55 : Quality Standard for Steel Castings for Valves, Flanges and Fittings and other Piping Components - Visual Method 

4.11 MSS SP-91 : Guidelines for Manual Operation of Valves 

 5.0 Safety and Environmental Requirements. 

5.1 The execution of the provisions of this procedure is entrusted to appropriately qualified and experienced personnel because it calls for procedures that may be injurious to health if adequate precautions are not taken. 

5.2 It is responsibility  to verify that appropriate safety and health practice and devices have established by the Health, Safety & Environmental responsible. 

5.3 Water used for pressure tests shall not be released out of the re-cycling circuit of pressure testing area. 

 6.0 Responsibilities 

 6.1 Operation Manager shall ensure all members of staff comply with the requirements of this procedure. 

6.2 Client shall ensure no changes are to their specification during the project and advice 

 of any planned changes or amendments. 

6.3 The health, safety & Environmental Department has the responsibility for the safety of the pressure test equipments and for everything is relevant to the safety execution of all pressure test in testing area. 6.4 The Shop Supervisor has the responsibility for the execution of : - All pressure test - Functional test - Availability of all testing equipments - Handling and transportation of the tested valve. 6.5 The Quality Control Inspector is responsible for the operation of this procedure and ensure the necessary records and logs are kept such as : - Verify for the current calibration and adequacy of the pressure gauges used. - Evaluate the result of all pressure tests carried out. - Verify that the requirements of this specification are correctly fulfilled. - Issue the pressure test report relevant to the pressure test carried out.

 

 7.0 Pressure Test General Requirements 

7.1 General 

7.1.1 During pressure testing of valves, if any leaks are detected is out of the specified or standard acceptance criteria, Operation Manager and Quality Control Manager shall be notified of the Non Conformance Products in accordance with Non Conforming Materials/ Products Procedure. 

7.1.2 Prior to testing of valves, the pressure gauge shall be check for calibration dates and gauge reading zero when test bench machine is idle. 

7.1.3 Valves shall be visually inspected, if required washed and cleared of any foreign objects. 

7.1.4 Testing shall be performed in the sequence used in this clause for specifying the test requirements. Shell pressure testing shall be carried out before painting the valves. If the valve has been previously shell tested prior to external painting, any additional test may be performed with the valve externally painted. 

7.1.5 Valves shall be tested with the seating and sealing surfaces free from sealant except where the sealant is the primary means of sealing. 

7.1.6 Tests specified with the valve half-open may also be performed with the valve fully open provided the body cavity is simultaneously filled and pressurized through a cavity connection. 

7.1.7 Methods for monitoring pressures and/or leakage shall be adequate also when valve body connections are not available for direct monitoring. 

7.1.8 A sufficient stabilization period shall be allowed for all pressure tests. 

7.2 Test Location Pressure test performed workshop 

7.3 Test Equipment Test Equipment used Gate Valves are tested within specially constructed Test Bench. 

7.4 Test Required for Gate Valves 

7.4.1 The pressure test listed in Table A .- Pressure Tests, shall be performed on Gate Valve. 

7.4.2  option, the backseat test for gate valve that have the backseat feature may either a high-pressure or a low-pressure test unless stated otherwise in the purchase order. 

7.5 High-Pressure Closure Test For the gate valve for which, according to Table. A, the high-pressure closure test is optional, the gate valves are still required to be able to pass the test (as a test of the design of the valve closure structure). 

7.6 High-Pressure Pneumatic Shell Test When specified by the purchase order, a high-pressure pneumatic shell test shall be performed. This test shall be performed after the hydrostatic shell test, using appropriate safety precautions. The pneumatic shell test pressure shall be 110 percent the maximum allowable pressure at 100 0F (52 0C) or specified in the purchase order. Visible leakage is not allowed. 

7.7 Test Fluid 

7.7.1 For shell, and high-pressure backseat, and high-pressure closure tests, the test fluid shall be air, inert gas, kerosene, water, or a noncorrosive liquid with a viscosity not higher than of water. The fluid temperature shall not exceed 1250F (52 0C). The test fluid temperature may be specified in the purchase order for low-temperature valves. 

7.7.2 For the low-pressure closure and low-pressure backseat tests, the test fluid shall be air or inert gas.

 7.7.3 Water used for any test may contain a water-soluble oil or a rust inhibitor. When specified by the purchaser, a wetting agent shall be included in the water. For testing of austenitic stainless steel valve, water with chloride content not exceeding 100 ppm shall be used. 

7.8 Test Pressure 

7.8.1 The shell test pressure shall be in accordance with Table 1 (See Appendixes). 

7.8.2 Other test pressure shall be in accordance with Table 2 (See Appendixes). 

7.9 Test Duration For each type of test, the required test pressure shall be maintained for at least the minimum time specified in Table 3 (See Appendixes). 

7.10 TestLeakage For shell test, no visible leakage is permitted. If the test fluid is liquid, there shall be no visible evidence of drops or wetting of the external surfaces (no visible leakage through the body, body liner, if any, and body-to-bonnet joint and no structural damage). If the test fluid is air or gas, no leakage shall be revealed by established detection method. For both the low-pressure closure test and the high-pressure closure test, visual evidence of leakage through the disc, behind the seat rings, or past the shaft seals (of valves that have this feature) is not permitted and structural damage also is not permitted. (Plastic deformation of resilient seats and seals in not considered structural damage). The allowable rate for leakage of the test fluid past the seats, for the duration of tests, is listed in Table 3 (see Appendixes). 

8.0 Pressure Test Procedures 

8.1 General 

8.1.1 Gate valve designed to permit emergency or supplemental introduction of an injectable sealant to the seat or packing area shall be tested with the injection empty and not in use. 

8.1.2 When test fluid used a liquid, the valve shall be essentially free from air during the test. 

8.1.3 When closure testing gate valve, the valve manufacturer shall used a method of testing seat leakage that fills and the pressurizes the body cavity between the seats and the bonnet area, as applicable, with the test fluid. This will ensure that no seat leakage can escape detection because of gradual filling of these volumes during the test. 

 8.2 Shell Test The shell test shall be performed to check the soundness and integrity of the valve body by applying the pressure inside the assembled valve with the valve ends closed, the valve partially open, and any packing tight enough to maintain the test pressure. Non adjustable shaft seals (O-Rings, Packing, Gasket, and the like) shall not leak during the shell test. 

8.3 Backseat Test The backseat test shall performed by applying pressure inside the assembled valve with the valve ends closed, the valve fully open, and the packing gland loose. The backseat test may be performed immediately after the shell test, and all packing glands shall be retightened after the backseat test. The successful completion of the backseat test shall not be construed as a recommendation by CV. Renoya Fa that, while the gate valve is pressurized, the gate valve stuffing box may be repacked or the packing may be replaced. 

8.4 Low-Pressure Closure Test 

8.4.1 The low-pressure closure test shall be performed with the sealing surfaces clean and free oil, grease, and sealant. If necessary to prevent galling, the sealing surfaces may be coated with a film of oil that is not heavier than kerosene. 

8.4.2 The low-pressure closure test shall be made in accordance with one of the following procedures, as applicable : a. For a gate valve designed to close against pressure from both directions, the pressure shall be applied successively to each side of the closed valve with other side open to atmosphere to check for leakage at the atmospheric side of the closure. Any leakage at the seat, behind the seat ring, or through the disk on the open side of the valve shall be detected when bubbles are observed coming from the closure (disk, seat, and seat ring), which is either covered with water or coated with soap or similar solution. Leakage from the seats shall not exceed rates shown in Table 4. b. For a double block-and-bleed gate valve, the pressure shall be applied successively to each side of the closure through the valve port. Leakage into the body cavity between the seats shall be checked at the packing chamber (with no packing present) or through observation at the tapped opening between seats. valves shall be tested with the steam in vertical upright position. Leakage from the seats shall not exceed rates shown in Table 4. 

 8.5 High-Pressure Closure Test The procedure for the high-pressure closure test shall be the same As the procedure for the low-pressure closure test except that, the case of liquid test, leakage shall be detected when drops, not bubbles as described in 8.4.2., are observed. 

8.6 Test Pressure Steps 

8.6.1 Shell Test 

1. If possible, the gate valve shall be clamped securily to the Test Bench Machine and both ends of the valve shall be blanked off. If not possible to clamp in the Test Bench, the Blind bubbles as described in 8.4.2., are observed. 

2. Open gate valve and disc/wedge element is partially open. 

3. Open the fluid inlet line. 

4. Fill gate valve to the top with fluid thereafter closed the fluid inlet line. 

5. Dry external of gate valve using air line. 

6. Turn on pump and pressurized in accordance with specification (Refer to Table-1; and Table 2). 

7. Hold the specified pressure for the duration specified in (Table.3). 

8. Check for any leakage and record results in Pressure Test Report Form (see Appendixes). 

9. Acceptance criteria : For shell test if the test fluid is a liquid there shall be no visible evidence of drops or wetting of the external surfaces (no visible leakage through the body and body-to-bonnet joint and no structural damage). 

10. Turn off pressure slowly (to avoid damage of gauge). 

11. Open the outlet line. 

12. Allow all fluid to drain out. 

13. Open gate valve fully to allow fluid drain out. 

14. Dry the internal and external of gate valve using air line. 

15.Completed the test results on Pressure Test Report Form (See Appendixes). 

16. Continue to Backseat Test. 

 8.6.2 Backseat Test 

1. If possible, the gate valve shall be clamped securily to the Test Bench Machine and both ends of the valve shall be blanked off. If not possible to clamp in the Test Bench, the Blind Flanges shall be bolting securely to the both side of Tested Gate Valve by using Bolts and Nuts. 

2. Open valve fully to backseat. 

3. Open the fluid inlet line. 

4. Fill gate valve to the top with fluid thereafter closed the fluid inlet line. 

5. Loosen the packing gland. 

6. Dry external of valve using air line. 

7. Turn on pump and pressurized in accordance with specification (Table. 1 and Table-2) Hold the specified pressure for the duration specified in (Table.3) 

8. Check for any leaks around the loosened packing area. Record results in Pressure Test Report Form. 

9. Acceptance criteria : For backseat test no visible leakage is permitted. 

10. Turn off pressure slowly (to avoid damage of gauge). 

11. Open the outlet line. 

12. Unclamp gate valve from Test Bench or remove blind flange from one side of valve end. 

13. Allow all fluid to drain out. 

14. Dry the internal and external of valve using air line. 

15. Tighten the packing gland flange. 

16. Completed the test results on Pressure Test Report Form (Appendixes). 

17. Continue to Low-Pressure Closure Test. 

 8.6.3 Low-Pressure Closure Test 

1. If possible, the gate valve shall be clamped securily to the Test Bench Machine and one end of the valve shall be blanked off. If not possible to clamp in the Test Bench, the Blind Flanges shall be bolting securely to one end of Tested Gate Valve by using Bolts and Nuts. 

2. Closed the gate valve. 

3. Open the fluid inlet line. 

4. Fill the atmospheric side of the closure with clean water until covered the disc/wedge and seat rings. 

5. Turn on low pressure pump and pressurized the side of closed gate valve in accordance with specification (Table 1 and Table 2). 

6. Hold the specified pressure for the duration specified in (Table.3). 

7. Any leaks shall be detected when bubbles are observed coming from closure at the atmospheric side of the closure (the valve end downstream of the pressurized test fluid) during duration of test. 

8. Record results in Pressure Test Report Form (see Appendixes). 

9. Acceptance criteria : The allowable rate for leakage of test fluid past the seats, for the duration of the low- pressure closure test is listed on (Table.4). 10. Turn off air pressure slowly (to avoid damage of gauge). 

11. Repeat instructions 2 through 9 to perform low-pressure closure test at the opposite valve end. 

12. Continue to High-pressure closure test. 

8.6.4 High-Pressure Closure Test 

1. If possible, the gate valve shall be clamped securily to the Test Bench Machine and one end of the valve shall be blanked off. If not possible to clamp in the Test Bench, the Blind Flanges shall be bolting securely to one end of Tested Gate Valve by using Bolts and Nuts. 

2. Closed the gate valve. 

3. Open the fluid inlet line. 

4. Fill the side of closed gate valve to the top with fluid thereafter closed the fluid inlet line. 5. Turn on high pressure pump and pressurized the side of closed gate valve in accordance with specification (Table 1 and Table 2). 

6. Hold the specified pressure for the duration specified in (Table.3). 

7. Any leaks shall be detected when drops are observed coming from closure at the atmospheric side of the closure (the valve end downstream of the pressurized test fluid) during duration of test. 

8. Acceptance criteria : The allowable rate for leakage of test fluid past the seats, for the duration of the high- pressure closure test is listed on (Table. 4). 9

. Turn off air pressure slowly (to avoid damage of gauge). 

10. Repeat instructions 2 through 9 to perform high-pressure closure test at the opposite valve end. 

11. Open the Gate valve fully to allow all fluid to drain out. 

12. Dry the internal and external of valve using air line. 

13. Apply light oil on internal surfaces of the valve. 

14. Closed the valve and put in "Final Inspection Area". 

 9.0 Appendixes