Bolted Bonnet; Swing disc; Metallic seating surfaces. Swing Check Valve with lever & weight
Body and Bonnet Connection
The body and bonnet of Class 150-Class 900 check valves are usually with studs and nuts. And the body and bonnet of Class 1500-Class 2500 check valves are usually of pressurized seal design.
Stainless steel + flexible graphite wounded gasket is used for Class 150 and Class 300 check valve; Stainless steel + flexible graphite wounded gasket is used for Class 600 check valve, and joint gasket is also optional for Class 600 check valve; Ring joint gasket is used for Class900 check valve; Pressurized seal design is used for Class 1500-Class 2500 check valves.
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 NPS<8 check valves, and welded on seat can be also optional if being requested by the customer. Welded on seat is used for NPS>12 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.
Design and Manufacture: API 6D, BS1868 or ASME B16.34
Inspection and Test: API 598/API 6D
End flange dimension: ASME B16.5, ASME B16.47 (API 605 ,MSS SP44)
BW end dimension: ASME B16.25
Face to face and end to end: ASME B16.10/API 6D
Pressure-temperature ratings: ASME B16.34
ASTM A216 WCB WCC; ASTM A217 WC1 WC6 WC9; ASTM A351 CF8, A351 CF8M,
A351 CF3, A351 CF3M, A351 CN7M; ASTM A352 LC1 LCB LCC LC3 or by customers
Hastelloy C276, Monel, Titanium and Alloy 20 (Cast Steel, Alloy Steel, Stainless Steel, Special Steel)