Patent ID: 7100893

Claim:
A gate valve comprising: a polymeric monolithic liner defining a valve element cavity, the liner having a first side, a second side, a first cylindrical flange portion projecting outwardly from said first side, and a second cylindrical flange portion projecting outwardly from said second side, said first and second cylindrical flange portions defining a fluid passageway through said liner transverse to said valve element cavity, said liner having an upper open end forming an entrance into said valve element cavity, said upper open end of said liner defining a seal pocket; a first housing portion having a first front face, a first back face, and a first throughbore for receiving said first annular flange portion; a second housing portion having a second front face, a second back face, and a second throughbore for receiving said second annular flange portion, a liner cavity being formed between the back faces of said first and second housing portions; a yoke adapter, said yoke adapter having a body forming a top surface and bottom surface, a slot extending through said top and bottom surfaces, said yoke adapter being secured to said housing portions, said bottom surface of said body overlying said seal pocket; a first face ring, said first face ring including a first cylindrical tubular portion and a first radially outwardly projecting, annularly extending face ring flange, said first tubular portion being received in said first annular portion; a second face ring, said second face ring including a second cylindrical tubular portion and a second radially outwardly projecting, annularly extending face ring flange, said second tubular portion being received in said second annular flange portion; a gate valve element slidably received in said valve element cavity; an elastomeric seal received in said seal pocket in surrounding relationship to said gate valve element, said elastomeric seal being sized such that when said yoke adapter is secured to said first and second housing portions, said elastomeric seal is placed under a predetermined amount of compression to snugly engage said gate valve element.