ON-OFF VALVE FOR POWDER FLOW PASSAGE

PROBLEM TO BE SOLVED: To provide an on-off valve for a powder flow passage capable of preventing any catch of powder in a substantially complete manner when closing a valve element. SOLUTION: In the on-off valve for the powder flow passage, a circular valve element 14 for opening/closing its flow passage is built in a powder flow passage 13 formed inside a cylindrical valve body 11, and an outer circumferential part of the valve element 14 is brought into contact with a seat ring 12 provided along an inner circumferential surface of the flow passage of the valve body 11 by the turn of the valve element 14 to close the flow passage 13. The valve element 14 has an air feed hole 18 extending in the radial direction and opened at an end face of a valve stem, and a plurality of air jet holes 19 extending radially from a center of the valve element 14 and communicated with the air feed hole. Compressed air is fed to the air feed hole 18 when closing the valve element 14, the compressed air is jetted outwardly in the radial direction of the valve element 14 from the air jet holes 19, and powder is blown with the jet air to prevent the powder from being caught by an abutted part of the valve element 14 and the seat ring 12. COPYRIGHT: (C)2009,JPO&INPIT