Patent ID: 6279875
Filing Date: 2001-08-28
Classification: F16K

Abstract:
A gate valve comprising:a gate valve body having a gate chamber therein, inlet and outlet passages extending through said gate valve body and being in communication with said gate chamber to define a flow path through said gate valve body, said gate valve body having a recess surrounding said inlet and outlet passages adjacent to said gate chamber;a telescoping seat assembly in each of said recesses, each said telescoping seat assembly including,a first seat element defining a receptacle surface therein;a second seat element defining an outer surface, said outer surface being telescopingly received within said receptacle surface of said first seat element such that said first seat element and said second seat element are each moveable in an axial direction with respect to said flow path;said first seat element and said second seat element defining therebetween a seal cavity between said receptacle surface and said outer surface; anda unidirectional seal element disposed in said seal cavity, said unidirectional seal element having an open end and a closed end, said open end having lip seal surfaces for sealing between said first seat element and said second seat element; anda gate positioned within said gate chamber, said gate being moveable within said gate chamber between an open position to allow fluid flow through said flow path and a closed position to prevent fluid flow through said flow path.