
Carbon steel or stainless steel + flexible graphite combined gasket is used for Class150 gate valve; stainless steel + flexible graphite spiral wound gasket for Class 300 gate valve; stainless steel + flexible graphite spiral wound gasket for Class 600 gate valve, and ring type joint gasket is optional for Class 600 gate valve; ring type joint gasket is used for Class 900 gate valve; pressurized seal design is used for Class1500 to Class 500 gate valve.
For carbon steel gate 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 gate valves, and welded on seat can be also optional if being requested by the customer, Welded on seat is used for NPS 10 carbon steel gate valves. For Stainless steel gate valve, integral seal is usually adopted, or to weld hard alloy directly integrally.
The gate valves disc is rubber-packed to get excellent sealing effect by the rubber's resilient deformation. Non-rising resilient seated gate valves solve the problem in general gate valve such as leakage, rusting etc. and saves installation space. It is used widely in tap water industry, sewage treatment, shipping construction, petroleum, chemicals, food, pharmacy, textile, electric power,