Self-regulated pressure control valve

An automatically set pressure reducing valve comprising:

• fluid passage means defining a primary side and a secondary side of said valve;
• valve means controlling flow through said fluid passage means between said primary side and said secondary side;
• a diaphragm for actuating said valve means, said diaphragm being exposed on one side to said secondary side of said fluid passage means;
• pressure setting spring means operatively associated with said diaphragm for determining an operating pressure at which said valve means open and close;
• means for adjusting the resilient force of said spring means;
• actuator means responsive to fluid pressure on said secondary side of said fluid passage means for controlling said adjusting means to determine said operating pressure in response to changes in pressure on said secondary side, said actuator means comprising an actuator element, the pressure on the secondary side varying according to a predetermined function with the position of the actuator element;
• and
• control means including means for establishing a target value for a set pressure and means for sensing difference between said target value and the pressure on said secondary side, said target value being established based on the predetermined functional relationship between the pressure on said secondary side and the position of said actuator element;
• said actuator means being placed in operation when a differences detected between the pressure on said secondary side and said target value is larger than a standard difference, with said actuator means being placed out of operation when said detected difference has become smaller than said standard difference.