Suck back valve

摘要

A suck back valve is proposed, comprising a suck back mechanism (28) for sucking a coating liquid inside a fluid passage (38) under a negative pressure action of a diaphragm displaced by a pilot pressure, an ON/OFF valve (26) for opening and closing the fluid passage (38) under action of the pilot pressure, and a flow amount control device (115) for controlling the pilot pressure supplied to the ON/OFF valve (26).