Patent ID: 7931251
Filing Date: 2011-04-26
Classification: F16K,Y10T

Abstract:
1. An expanding gate valve mechanism, comprising: a valve body defining a valve chamber and flow passages intersecting said valve chamber and having spaced sealing surfaces; a valve stem being linearly moveable to valve opening and closing positions within said valve body and having driving connection with said first and second gate members, upon initial linear opening movement said valve stem causing sequential opening movement of said second gate member prior to initial opening movement of said first gate member; said wedge member being movably disposed between said first and second gate members and being moveable with said first and second gate members during opening and closing movement of said gate valve mechanism; and a stop member being located within said valve body and being positioned to stop linear closing movement of said wedge member; and continued closing movement of said first and second gate members by said valve stem relative to said wedge member causing expansion movement of at least one of said first and second gate members by said interacting tapered surface engagement and forcing said first and second gate members into tight sealing engagement with said spaced sealing surfaces.