Patent ID: 7090190

Claim:
A flow control valve comprising: a valve seat; a valve body which is movable into or out of contact with the valve seat; a pilot chamber into which compressed air is supplied, thereby moving the valve body to place the valve in an opened state; a spring which urges the valve body in close contact with the valve seat to place the valve in a closed state; and an electro-pneumatic regulator that controls supply and discharge of compressed air into or from the pilot chamber, the electro-pneumatic regulator comprising: a proportional intake valve that supplies compressed air into the pilot chamber; a proportional discharge valve that discharges compressed air from the pilot chamber; and a passage block internally provided with (i) a supply passage through which a supply source of the compressed air and the pilot chamber are brought into communication by the proportional intake valve; (ii) a discharge passage through which the pilot chamber and the outside are brought into communication by the proportional discharge valve, and (iii) a communication passage through which the pilot chamber and the outside are brought into communication not through the proportional discharge valve.