CHECK VALVE

摘要

A first object is to provide a check valve that makes the use of coil springs unnecessary and is capable of increasing flow rate. It comprises a valve chamber (12), a first pipeline (13) and a second pipeline (14) that open at the positions opposed to the valve chamber, valve seats (13a, 14a) formed at the valve−chamber−side ends of the first and second pipelines, a delivery pipeline (15) that opens intermediately between the two valve seats, and a valve body (16) movable between the two valve seats in the valve chamber. The first and second pipelines (13, 14) are automatically switched so that the pipeline having a higher pressure is connected to the delivery pipeline (15) in order for a fluid to flow. In this case, the absence of any coil spring in the flow channel allows the latter to be increased in size, and there occurs no problem about the wear of coil springs. Further, the valve body (16) can be placed outside the flow channel, and from this point of view also, the flow rate can be increased.