Single Expanding

The single expanding gate valve (model B22) is the intermediate solution between the slab gate and the double expanding gate: a gate-and-segment assembly wedges mechanically against the seat at full closure, providing a positive seal that does not depend on line pressure, in a body shorter and lighter than a double expanding valve.

The design is suitable for isolation duties where a mechanically energized seal is required — low differential pressure, positive isolation for maintenance — but where the footprint, weight or budget of a double expanding valve is not justified. As with all Valland through conduit gate valves, the bore is full and piggable and the back seat allows stem seal maintenance with the valve in line.

Model B22 is designed to API 6D, API 6DSS or API 6A with cast or forged single-piece body, bolted bonnet, metal-to-metal hardfaced seats, and manual or actuated operation.