Patent ID: 8123195
Filing Date: 2012-02-28
Classification: F16K

Abstract:
1. A pressure control butterfly valve comprising: a valve disc rotatable in a vertical direction relative to a flow passage in a body; a seat ring reciprocating in a direction of the flow passage to allow a valve seat seal part to abut on and separate from the valve disc; a valve opening/closing mechanism provided with an airflow path to which air is supplied in a direction of separating the seat ring from the valve disc and with a spring for biasing the seat ring toward the valve disc; and an electromagnetic valve for supplying the air from a pump to the airflow path and stopping the supply of the air and an electropneumatic regulator which are connected in parallel; wherein the valve opening/closing mechanism is for nonslidably rotating the valve disc from which the seat ring has been separated by supply of air to the airflow path and for allowing the seat ring to abut on and separate from the valve disc by means of the supply of air to the airflow path and a biasing force of the spring when the valve disc has been rotated to a valve-closed state, thereby controlling pressure in the flow passage.