Unlike soft-seated valves that fail under high thermal stress, the metal-to-metal seat withstands extreme temperatures and sudden thermal shock without binding or losing sealing integrity. A disc-spring (spring-loaded) seat structure absorbs the thermal expansion of internal parts at high temperature, so the valve continues to open and close smoothly without seizing.

Available with uni-directional sealing — preferred for high differential pressure, where line pressure energises the seat for tighter sealing — or bi-directional sealing, selected to suit the system layout and safety requirements. For floating valves the flow direction is marked on the body; bi-directional sealing is supplied on request.

For trunnion-mounted designs, spring-loaded metal seats exert constant pressure against the ball, providing reliable double block and bleed. With the valve closed and the central cavity drained through the bleed valve, the upstream and downstream seats block independently, letting operators safely isolate and vent the valve cavity under full pipeline pressure.

A unique ball-grinding process rotates the ball against the grinder at varying positions to achieve high roundness and surface finish. Low-pressure sealing is provided by spring pre-tension, while a carefully designed seat piston effect achieves high-pressure sealing using the medium pressure itself. Tightness meets ANSI B16.104 Class IV.

In the metal-to-metal structure the gasket is stainless steel + flexible graphite and the packing is flexible graphite, ensuring reliable sealing even in the event of fire.