Fast closing valve, operated by pneumatic action, for pipelines for the transport of solid materials

Valve designs previously known do not meet the stringent requirements in nuclear reactor application, e.g., to close pipelines for the transport of fuel elements which must permit operation over prolonged periods of time under completely tight conditions while requiring no maintenance. In the ivention a closing valve is proposed in which the movable sealing elements, which are designed as pistons, are moved into their sealing positions by pneumatic action. A tension spring and a throttle cause it to be forced against its seat only after the piston has come to rest in its locked position. The fluid used to transport the solid is the same gas which is employed to pressurize the piston. (UA)