Knife gate valve

A gate valve comprising:

• an elongated, rigid, valve frame having first and second ends, said valve frame comprising two rigid plates and spacing means extending between said two rigid plates for spacing said rigid plates a fixed space one from another, said two rigid plates defining aligned holes extending laterally therethrough for forming a fluid passage through said valve frame, said spacing means being positioned between said plates about said fluid passage, but being spaced from said fluid passage, and not being positioned directly on a first-end side of said fluid passage to thereby leave a free slot from said first end to said fluid passage;
• a relatively-resilient valve liner means of a size and shape for selective insertion thereof into said frame, between said rigid plates, from said first end, said relatively-resilient valve liner means comprising two side inserts, with a spacer insert positioned therebetween for defining a slot extending into said liner from said first end, said liner means defining a hole communicating with said slot extending laterally therethrough for forming a fluid passage to coincide with the fluid passage of said frame when said liner means is mounted in said frame, said liner means being seated between said frame plates around the periphery of said fluid passages;
• a gate blade for extending into said liner-means slot from said first end for moving into, and out of, a blocking position for fluid passing through said coinciding fluid passages of said frame and said liner means;
• and
• a drive means positioned at said first end linked to said gate blade for moving said gate blade in said slot.