Patent ID: 7051994

Claim:
A curtain value comprising: a valve body having an inside surface, an inlet port comprised of an opening through said inside surface of said valve body and enabling fluid flow into the valve body, an outlet port comprised of an opening through said inside surface of said valve body and enabling fluid flow from the valve body, and a closure insert comprising a pivotable shaft, a pivot arm on said pivotable shaft, a closure support extending over said opening of said outlet port when positioned in said valve body, and a flexible diaphragm as a curtain valve closure for controlling fluid flow through said outlet port between a closed position wherein it covers said outlet port and an open position wherein it is displaced circumferentially relative to said pivotable shaft from said outlet port, said flexible diaphragm being extended between two locations, one of said two locations being a pivotally-moveable support on said pivot arm and the other location being a fixed support on said closure support, whereby pivotal movement of said shaft moves said pivot arm through a portion of a full turn and, thereby, moves said flexible diaphragm between said open and said closed positions.