Patent ID: 9046185
Filing Date: 2015-06-02
Classification: F15B,F16K

Abstract:
1. A method for determining a position of an open/closed-valve positioned by a pneumatic actuating drive and movable to a completely opened open position and a closed position depending on operating requirements, comprising the steps of: during normal operation the actuating drive pneumatically influencing with an i/p converter a pneumatic working chamber of the actuating drive such that the open/closed-valve moves to one of the open/closed positions and, in the case of a predefined operating condition, the i/p-converter allowing the working chamber to vent so that the open/closed-valve automatically moves to the other one of the open/closed positions; capturing at least one of the pressures selected from a group consisting of a pressure prevailing in the working chamber and a pneumatic control pressure output at the i/p converter continuously over time; and determining a pressure change over time which defines a pressure versus time pattern, wherein said pressure versus time pattern of the pressure change is compared to an expected pressure pattern based on saved empirical values of a faultlessly working open/closed-valve, and in case of exceeding a predetermined deviation tolerance of the pressure versus time pattern with respect to the expected pressure pattern an error signal is generated.