New 7/8inch direct-acting pressure relief valve cartridge

This valve features a simple, robust, spool-type design and makes use of tried and tested components and technologies. The accurate, high-quality manufacture results in an excellent surface finish and concentricity, thereby minimising internal leakage. Pressure in the regulated port acts on the spool and closes it against the force of the spring. As pressure in the regulated port increases, the spool shifts, thereby controlling the inlet pressure; equilibrium is then achieved and a reduced constant outlet pressure held. Altering the adjuster changes the force applied to the spool and hence the pressure in the regulated line.

Used to provide an adjustable regulated pressure that is lower than supply pressure, the valve is useful when more than one operating pressure is required from one pump. Direct acting valves such as this are suited to low-flow applications and regulated pressures up to 140bar (2000psi). This valve also acts as a relief valve, relieving from regulated line to tank if shock or surge pressures occur. Typical applications for this include: brake circuits, clutch control, pilot systems and pump swash control.

These cartridge valves can be fitted into standard line bodies or used, with other valves required in a system, in hydraulic integrated circuits or manifold blocks. If the latter option is used, designers can reduce the number of joints in the system, thereby minimising the possibility of oil leaks and concentrating most or all of the valves into one self-contained, pre-tested block to both speed assembly and reduce space requirements.