Barksdale's pressure regulators are sensitive pressure-control devices used to maintain a pre-determined pressure in a hydraulic circuit. The regulated output pressure can be controlled either by the force of a spring or a motor (hydraulic or pneumatic). Design features ensure excellent accuracy, repeatability, and high flow coefficients. Designed to provide years of trouble-free operation and virtually zero leakage, the Shear-Seal® design uses fluid pressure to maintain a leak-free metal-to-metal seal that improves with use. The shearing action between the rotor & pressure seal continually laps the mating surfaces and prevents contaminates from lodging between the sealing surfaces. The result is a valve that doesn't wear out – but wears in over time, providing you superior control consistently throughout the entire life of the product.