Spool-type logic element simplifies hydraulic control

The LE402, as with other Integrated Hydraulics cartridge valves, has excellent characteristics. Careful sleeve and spool design give low pressure drops, thereby preventing excessive amounts of energy from being wasted, and the close tolerancing of the spool and sleeve ensures minimal internal leakage.

Suitable for use in many hydraulic circuits, the valve is very flexible in its application. It can be controlled by a number of different pilot cartridges: for example, screwing a small 1 l/min relief into the back of the cartridge enables it to function as a main 350bar relief with flows of up to 350 l/min; or fitting a proportional pilot relief valve transforms the valve into a high-flow proportional relief valve. Alternatively, fitting a pilot solenoid valve produces a 350 l/min electrically operated dump valve. This is an added advantage when it comes to inventory costs, as only one component needs to be stored - into which interchangeable valves can then be screwed to alter the function.

Space-saving design

The product is also compact because the controlling cartridge is simply screwed into the back end of the main cartridge. Furthermore, the amount of machining required to install the cartridge is minimal too, as only one cavity is required due to the utilisation of the piggy-back valve design.

Maximum working pressure on the nose is 350bar and maximum tank line pressure is 210bar; the nominal flow rate is 350 l/min. 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, the designer can reduce the number of joints in the system, thereby minimising the possibility of oil leaks, and concentrate most or all of the valves into one self-contained, pre-tested block, which both speeds assembly and reduces the space requirement.