ADJUSTMENT DEVICE FOR AN OPEN-CLOSE VALVE

An adjustment device for an open-close valve (1) has a pneumatic drive (2) which is aerated or de-aerated according to the presence or absence of a control voltage (Vs) which can be supplied by a control system (5). The valve (1) moves into an operating position when the drive is aerated, and into a safety position when the drive is de-aerated. The valve (1) is provided with an electro-pneumatic position regulator (8) for carrying out a partial stroke test. In order to reduce the technical demands of the invention, the electro-pneumatic position regulator (8) is directly connected to the pneumatic drive (2) with no interconnection of a magnetic valve controlled by the control voltage (Vs); the position regulator (8) is connected on the voltage supply side to the control voltage (Vs) which can be supplied by the control system (5), and is designed to de-aerate the pneumatic drive (2) if the power supply is interrupted; a routine for carrying out the partial stroke test, and a value for the set position of the valve (1) in the operating position are stored in the position regulator (8).