SPRING-LOADED TANDEM CONTROL VALVE

摘要

The fitting, in particular a safety valve, operates according to the relief principle or according to the loading principle. The fitting is opened and closed by a plurality of control parts. The control parts are connected in series in the control line of the fitting and are each actuated by a control valve. The control parts open the fitting only when all the control parts are in a position which opens the fitting. The fitting closes as soon as even only one of the control parts is in a position which closes the fitting.