VALVE DEVICE

PURPOSE:To prevent the inrush of a liquid to a secondary pressure path from a primary pressure path by producing a delay time when the primary pressure is switched to the primary pressure in a pressure chamber. CONSTITUTION:A control valve 5 is provided at the primary pressure path side of a valve port 3 together with a cut-off valve 7 provided at the secondary pressure path side of the port 3 and controls the opening and closing. The primary pressure and the secondary pressure are selectively applied to a pressure chamber 8 which applies the action pressure to the valve 7. Furthermore a delay time is given for a period when the chamber 8 is switched to the secondary pressure from the primary pressure till the chamber 8 reaches secondary pressure. In other words, the primary pressure is applied to the chamber 8 so that the valve 7 is kept closed when the valve 5 is kept close. Then the secondary pressure is switched to the primary pressure in the chamber 8. Thus the valve 7 is gradually opened based on the delay time set by the time constant that is decided from the capacity of the chamber 8 and the pressure applied to the chamber 8. As a result, the inrush of a fluid can be prevented to the secondary pressure path.