Checklist – Valves

BF Valve

• Review manufacturer’s Inspection Test Plan
• Review Material certificate of valve body/bonnet, trim parts/bonnet fastners for compliance to specification
• Witness mechanical test of valve body/bonnet test coupons per specification
• Witness HIC/SSCC test per heat if applicable
• Verify heat treatment report of valve body/bonnet parts
• Bolting material with a mechanical strength above ASTM A 193 Grade B7 or hardness exceeding HRC22 shall not be used for valve applications where hydrogen embrittlement may occur.
• Verify the visual inspection of castings <MSS SP-55> <PICTURE- poor quality hole plugging in flange>
• Verify hardness test of body bonnet, trim part for compliance to specification. For NACE compliant valves randomly check the hardness values at weld repair areas on valve body <NACE MR 0175>
• Review Impact test result of pressure components if applicable <IS0 148 or ASTM A 370>
• Review manufacturer’s WPS, WPQT, PQR <ASME Set IX or EN 288 (for welded ones)>
• Review MPI and DPI test on machined surface of casting/forging
• Review radiography/UT test report of valve body casting if applicable
• Review fire safe type test certificate if applicable<BS 6755 Part 2, API Spec 6FA, API Spec 6FC, API Spec 6FD or API Std 607, IS0 10497>
• Review paint film thickness & type of paint applied <PICTURE- sample of poor internal coating>
• Review galvanising/cadmium plating/PTFE coating report for fasteners if applicable
• Review ENP coating thickness for the Ball if applicable
• Verify the flange dimensions- On higher size valves make sure whether it is s eries A or series B flange as per ASME B16.47
• Witness hydrotest (body, seat, backseat) including low pressure air test per standard & functional test with actuators. See the requirements for following codes
  • API 6D
  • API 598
  • ASME B16.34
• Verify preseration and protection provided for gasket seating surface
• Verify qualification of NDT personnel, <ASNT SNT-TC-IA Level II>, calibration of test and measuring instrument
• Verify marking per PO requirements and standards
• Packing and Preservation inspection
• final document review

API 6D / IS0 14313 requirements-

• Stem backseat test
  • The valves shall be filled with the ends closed off and the obturator in the partially open position until leakage of the test fluid around the stem is observed. The backseat shall then be closed and a minimum pressure of 1.1 times the pressure rating for material at 38°C (100°F) is applied for the duration specified in Table.
  • Monitoring for leakage shall be through a test access port or by monitoring leakage around the loosened packing.
  • No visible leakage is permitted at this test pressure.

 

Table -Minimum duration of stem backseat tests

Valve size – NPS inches	Test duration (minutes)
<= 4	2
>= 6	5

• Hydrostatic shell test
  • Hydrostatic shell testing shall be performed on the fully assembled valve prior to painting
  • Valves shall be closed off and the obturator placed in the partially open position during the test.
  • The test pressure shall be 1.5 or more times the pressure rating determined for material at 38°C (100°F).
  • The duration shall not be less than that specified in Table.
  • No visible leakage is permitted during the hydrostatic shell test.

Table -Minimum duration of hydrostatic shell tests

Valve size – NPS inches	Test duration (minutes)
1/2 to 4	2
6 to 10	5
12 to 18	15
>= 20	30

• Hydrostatic seat test
  • High-pressure gas seat testing may be performed in lieu of the hydrostatic seat test described below.
  • Lubricants shall be removed from seats and obturator sealing surfaces except, by agreement, for assembly lubricants for metal-to-metal contact sufaces.
  • The test pressure for all seat tests shall not be less than 1.1 times the pressure rating for material at 38°C (100°F). The test duration shall be in accordance with Table .

   

  Table -Minimum duration of seat tests

Valve size – NPS inches	Test duration (minutes)
1/2 to 4	2
>= 6	5

• Acceptance criteria
  • Leakage for soft-seated valves and lubricated plug valves shall not exceed IS0 5208 Rate A (no visible leakage).
  • For metal-seated valves the leakage rate shall not exceed IS0 5208 Rate D, except that the leakage rate during the seat test in 10.4.5.5.2 shall not be more than two times IS0 5208 Rate D unless otherwise specified.

ASME B16.34 requirements-

• Hydrostatic shell test
  • Each valve shall be given a shell test at a gage pressure no less than 1.5 times the 100°F rating, rounded off to next higher 25 psi increment. The test shall be made with water, which may contain a corrosion inhibitor, with kerosene, or with other suitable fluid,’ provided such fluid has viscosity not greater than that of water, at a temperature not above 125°F. Visually detectable leakage through pressure boundary walls is not acceptable. Test duration shall be not less than shown below.
  • Leakage through the stem packing shall not be cause for rejection,however,stem seals shall
    be capable of retaining pressure at least equal to the 100°F ratings without visible leakage.

Table -Minimum duration of hydrostatic shell tests

Valve size – NPS inches	Test time (seconds)
2 and smaller	15
2.5 to 8	60
10 and larger	180

• Valve Closure Tests

• Each valve designed for shut-off or isolation service, such as a stop valve,and each valve designed for
  limiting flowreversal,such as a checkvalve, shall be given a closure test. The test fluid shall be as in shell test. The test pressure shall be not less than 110% of the 100°F rating except that, at the anufacturer’s option, a gas closure test at gage pressure not less than 80 psi may be substituted for valve sizes and pressure classes shown below.
  Valve Size, NPS————————— Pressure Class
  12and smaller —————————–400 and lower
  4 and smaller ——————————All
• The closure test shall follow the shell test except that for valves NPS 4 and smaller with ratings Class 1500 and lower the closure test may precede the shell test when a gas closure test is used. The closure test duration shall be not less than shown below.

API 598 requirements-

Valve Type (For NPS =<4″ Class <=1500 AND NPS >4″ Class <=600)
—————————————————————————————Floating —-Butterfly and
Test Description —Gate ———-Globe——– -Plug ————Check ——Ball ——–Tunion-Mounted Ball
Shell ——————Required ——-Required —-Required ——-Required —-Required –Required
Backseat- ————Required ——-Required —-NA ————–NA ———-NA ———–NA
Low-pres. closure–Required ——Optional —–Required——- Alternative–Required —Required
High-pres. closure–Optional ——-Required—–Optional——— Required –Optional —-Optional

Valve Type (For NPS =<4″ Class >1500 AND NPS >4″ Class >600)
—————————————————————————————Floating —-Butterfly and
Test Description —Gate ———-Globe——– -Plug ————Check ——Ball ——–Tunion-Mounted Ball
Shell ——————Required ——-Required —-Required ——-Required —-Required –Required
Backseat- ————Required ——-Required —-NA ————–NA ———-NA ———–NA
Low-pres. closure–Optional ———Optional —-Optional ——Altemative— Required —Optional
High-pres. closure–Required ——Required—- Required ——-Required —Optional —-Required

Shell Test Pressure :
———————————————————————–Shell Test Pressure (minimum)
—————————————————————————-Pounds per Square Inch
Valve Type —————————–Class ———————Gauge ———————-Bar

Ductile iron —————————–150 ————————400 ————————26
——————————————-300 ————————975———————— 66

Cast iron ——————————–125
NPS 2-12 ————————————————————-350 ————————25
NPS 14-48 ————————————————————265 ————————19

Cast iron ——————————-250
NPS 2-12 ————————————————————–875 ———————–61
NPS 14-24 ————————————————————525 ———————–37
Steel
Flanged and butt-weld ————-150-2500 ———————– a
Screwed and socket-weld ————–800 ————————-b
—————————————155-2500 ————————a
a – Per ASME B16.34.
b – For Class 800 valves, the shell test pressure shall be 1 1/2 times the pressure rating at 100°F (38°C). rounded off to the next higher increment of 25 pounds per square inch gauge (or 1 bar)

Other Test Pressures:
———————————————————————–Minimum Test Pressure
Test
———————————————————————————Pounds per
—————————————————————————–Square Inch Gauge————Bar

——————-Valves Except Butterfly and Check

High-pressure closure and backseat a——————————————- b
Low-pressure closure and backseat a —————————————– 60-100 ——————- 4-7

———————Butterfly Valve
High-pressure closure————————————————————- c
Low-pressure closure————————————————————60- 100 —————— 4-7

———————Check Valve
High-pressure closure
Class 125 (cast iron)
NPS 2-12 ————————————————————————- 200 ———————- 14
NPS 14-48 ———————————————————————— 150 ———————- 11

Class 250 (cast iron)
NPS 2-12 ————————————————————————- 500 ———————– 35
NPS 14-24 ———————————————————————— 300 ———————–21

Class 150 (ductile iron) ———————————————————- 250 ———————- 17

Class 300 (ductile iron) ———————————————————- 640 ———————- 44

Carbon, alloy, stainless steel,
and special alloys —————————————————————— b
Low-pressure closure ————————————————————-60- 100 —————-4-7

a — The backseat test is required for all valves that have this feature.
b — 110 percent of maximum allowable pressure at 100°F (38°C) in accordance with the applicable purchase specification.
c — 110 percent of design differential pressure at 100°F (38°C) in accordance with the applicable purchase specification.

Duration of Required Test Pressure

——————————————————————–Minimum Test Duration (seconds)
——————————————Shell ————————————————-Closure

Valve Size————Check Valves ————Other —————————Check Valves———- Other
(NPS) —————–(API Std 594) ————Valves ——Backseat ———(API Std 594) ———valves

<= 2————————60———————-15————-15——————-60——————–15

2 1/2 – 6 ——————-60 ———————-60 ————60 ——————60 ——————-60

8-12————————60 ———————–120 ———–60 —————-60 ——————120

>= 14———————-120 ———————-300 ———-60 —————-120 —————–120

Maximum Allowable Leakage Rates for Closure Tests
———————————–All Metal-Seated Valves Except Check —–Metal-Seated Check Valves
Valve Size–All Resihent- ——-Liquid Test a —————-Gas Test——Liquid Test —————-Gas Test
(NPS) ——Seated valves -(drops per minute) (bubbles per minute)-(drops per minute) (bubbles per minute)
<=2 ————-0 ———————–Ob ——————–Ob ————– c ———————— d
2 1/2 – 6 ——- 0 ———————- 12 ———————24 —————c ———————— d
8-12 ————-0 ———————–20———————40 —————c ———————— d
>= 14e ———-0 ———————-28 ———————56 —————c ———————— d
a – For the liquid test, 1 millimeter is considered equivalent to 16 drops.
b – There shall be no leakage for the minimum specified test duration . For liquid test, 0 drop means no visible leakage per minimum specified test duration. For gas test, 0 bubble means less than 1 bubble per minimum specified test duration.
c- The maximum permissible leakage rate shall be 0.18 cubic inch (3 cubic centimeters) per minute per inch of nominal pipe size.
d – The maximum permissible leakage rate shall be 1.5 standard cubic feet (0.042 cubic meter) of gas per hour per inch of nominal pipe size.
e – For check valves larger than NPS 24, the allowable leakage rate shall be per agreement between purchaser and manufacturer.

Valve Handbook (McGraw-Hill Handbook)

Pressure rating at 100°F for selective materials: <Indicative information only- For exect information refer to ASME B16.34>