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.
Stainless steel + flesible 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<10 check valves ,and welded on seat can be also optional if being requested by the customer.Welded on seat is used for NPS>12 crbon steel gate valves .Forstainless 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.