摘要 |
In one embodiment, a gate valve is provided that includes a seal plate disposed in a housing. An inflatable biasing member is retained on a first side of the seal plate and is positioned to surround a first opening formed through the housing. A ring seal is retained on a second side of the plate opposite the first side and is positioned to surround a second opening formed through the housing. At least one of the inflatable biasing member and the ring seal are adapted to create a vacuum seal around the first and second openings, respectively, when the inflatable biasing member is inflated. |