CHECK VALVE
Cast steel check valve
Standards
- Design and Manufacture: Cast steel check valve to BS 1868, ASME B 16.34 and API 6D; Forged steel check valve to API 602.
- Inspection and Test: API 598 or API 6D.
- End flange dimension: ASME B16.5 (for NPSQ24); ASME B16.47 series BQAPI 605 or ASME B16.47 series AQMSS SP – 44 (for NPSQ24).
- BW end dimension: ASME B16.25.
- Socket-weld dimension: ASME B16.11.
- Face to face and end to end: ASME B16.10.
- Pressure – temperature ratings: ASME B16.34.
- Wall thickness dimension: API 600 and BS 1868.
The Features Of Check Valve
Bolted Bonnet, Swing and lift disc; Metallic seating surfaces.
Body and Bonnet Connection
The body and bonnet of Class150 ~Class900 check valves are usually with studs and nuts. And the body and bonnet of Class1500 ~ Class2500 check valves are usually of pressurized seal design.
Body - To - Bonnet Joint
Stainless steel + flexible graphite wounded gasket is used for Class150 and Class300 check valve; Stainless steel + flexible graphite wounded gasket is used for Class600 check valve, and joint gasket is also optional for Class6Q0 check valve; Ring joint gasket is used for Class900 check valve; Pressurized seal design is used for Class 1500 ~ Class2500 check valves.
Seat
For carbon steel check valve, the seat is usually forged steel. The sealing surface of the seat is spray welded with hard alloy specified by the customer. Renewable threaded seat is used for NPSQ10 check valves, and welded on seat can be also optional if being requested by the customer. Welded on seat is used for NPSQ12 carbon steel gate valves. For stainless steel check valve, integral seat is usually adopted, or to weld hard alloy directly integrally. Threaded or welded on seat is also optional for stainless steel check valve if being requested by the customer.
Standards
Parts and material list
Note: The chart above only lists out some common composition of steel check valve parts. We may provide other different parts material composition according to the customer ‘s request or the actual valve working condition.
Class 150 & Class300 Cast Steel Swing Check Valve
Class 150 & Class300 Cast Steel Swing Check Valve
Class 150~Class900 Cast Steel Lift Check Valve
Class 150~Class1500 Wafer Dual Plate Check Valve
Design & Manufacture standard
- Design and Manufacture as per ASME B16.34, API 594.
- Connection ends dimension as per ASME B16.5 ASME B16.47.
- Face to face dimension as per API 594.
- Inspection and test as per API 598,
Main Size and Weight
Class 150~Class900 Wafer Lifting Check Valve
Design & Manufacture standard
- Design and Manufacture as per ASME B16.34, API 594.
- Connection ends dimension as per ASME B16.5 ASME B16.47.
- Face to face dimension as per API 594.
- Inspection and test as per API 598,
Main Size and Weight
Class 150~Class900 Non-Slam Check Valve
Design & Manufacture standard
- Design and Manufacture as per BS 1868Q ASME B16.34.
- Connection ends dimension as per ASMEB16.5.
- Face to face as per manufacturer’s standard.
- Inspection and test as per API S98.
Main Size and Weight
