Two-way high-pressure solenoid valve

Abstract

A solenoid-operated control valve has a primary piston and a secondary piston located within a sleeve, and a solenoid coil disposed about the sleeve to effect movement of the primary piston. The primary and secondary pistons are independently movable along the sleeve. The secondary piston defines a pilot orifice connected with a center passage. The primary piston has a seal pin that extends into the pilot orifice of the secondary piston to block and unblock the center passage with movement of the primary piston in relation to the secondary piston. A spiral cut scarf ring disposed about the secondary piston is in contact with both the secondary piston and the sleeve to allow controlled leakage of a fluid through the valve via space between the secondary piston and the sleeve. The leaked fluid is permitted to collect in a cavity between the primary and secondary pistons.