Shafer Valve Company

Russell E Robertson

A hydraulic pipeline valve operating system (10) includes a tank (12) which holds a quantity of unpressurized hydraulic fluid. A pump (14) provides that fluid under pressure to a valve actuator (11). The valve actuator has an actuator cylinder (40) having a piston (42) which is operatively connected to the pipeline valve (28). The fluid under pressure moves the piston (42) of the cylinder (40) to compress a spring (35) to open the valve (28). When the piston (42) of the cylinder (40) ceases movement, continued pumping moves a piston (53), of a smaller diameter than the piston (42), which also acts against the spring (35). An indicator rod (60) gives a visual indication of the position of the piston (53) and when it is at approximately its midstroke location, pumping of the fluid is terminated and the actuator (11) is set. Should ambient temperature conditions change, the piston (53) moves to accommodate such changes thereby leaving the piston (42) unaffected. When a pressure sensing valve (22) senses a predetermined pressure change in the fluid in the pipeline, a dump valve (23) is opened permitting the pressurized fluid in the system (10) to be transferred back to the tank (12). The spring (35) can thus move the piston (42) to close the pipeline valve (28).

Growing community of inventors

Ashland, OH, United States of America

Russell E Robertson