Shut-off valve for interrupting a flow of a fluid through a pipeline

A shut-off valve for interrupting a flow of a fluid through a pipeline, particularly a flow of high temperature air in a gas main associated with a blast furnace, said valve comprising:

• a valve body adapted to be connected to pipes of a pipeline, said valve body having a pair of spaced walls having openings aligned with each other and with the pipes when said valve body is connected thereto, said openings defining a valved passageway, said valve body having therein first and second chambers on opposite sides of said openings;
• a valve plate and a plate connected to said valve plate, said plate having therethrough an aperture, said valve plate and said plate being movably mounted within said valve body for simultaneous movement between a valve closed position, whereat said valve plate extends between and interrupts communication between said openings and said plate is in said second chamber, and a valve open position, whereat said valve plate is in said first chamber and said aperture in said plate is aligned with said openings in said spaced walls of said valve body;
• valve seats provided on said valve body at positions adjacent said first chamber and said openings;
• outer flanges on said valve plate at an end thereof remote from said plate, said flanges contacting said valve seats and closing communication between said first chamber and said second chamber when said valve plate is in said valve closed position, said flanges being within said first chamber and spaced from said valve seats when said valve plate is in said valve open position, thereby enabling communication between said first and second chambers;
• flanges extending outwardly from opposite major surfaces of said valve plate;
• a pair of seal devices, each said seal device being positioned within said valve body adjacent a respective said opening;
• means for urging each said seal device toward a respective said flange when said valve plate is in said valve closed position and toward a respective side of said plate, at a location surrounding said aperture therein, when said valve plate is in said valve open position;
• passage means in said valve plate, said passage means opening at a first end thereof into said first chamber outwardly of said outer flanges and opening at a second opposite end thereof freely outwardly of one of said flanges at a position remote from said first chamber;
• cooling means for introducing a gaseous cooling fluid into said first chamber, whereby when said shut-off valve in the closed position said outer flanges contact said valve seats to prevent said cooling fluid from passing between lateral clearances exterior of said valve plate into said second chamber, said cooling fluid passing through said passage means in said valve plate into said second chamber, and whereby when said shut-off valve is in the open position said cooling fluid passes between said outer flanges and said valve seats through said lateral clearances exterior of said apertured plate into said second chamber and then between limited clearances between respective seal devices and sides of said apertured plate into said passageway.