DA Series Pilot Operated Unloading Valve
Laiye has introduced the DA Series Pilot Operated Unloading Valve, designed to address a common source of waste in hydraulic circuits: a pump that keeps running at full pressure when nothing in the system needs flow.
The problem: holding pressure when flow is not needed
In circuits with accumulators, or in dual-pump systems, there are periods when the pump is not required to deliver flow. A relief valve modulates flow to hold pressure, which keeps the pump loaded and generates heat. On equipment that runs long shifts, this adds up.
The solution: pilot-operated unloading
The DA Series takes a different approach. When system pressure reaches a preset value, the valve shifts fully and diverts pump flow back to tank. The pump runs unloaded. When pressure drops below the set point, the valve closes and the pump builds pressure again.
The valve is pilot operated. The main spool is shifted by pilot pressure rather than a heavy spring, which allows it to work at higher flows without a stiff spring that would wear out or need constant adjustment.
Three flow classes are available:
Spec 10: 60 L/min
Spec 20: 120 L/min
Spec 30: 240 L/min
All three share a maximum working pressure of 31.5 MPa and a pressure adjustment range of 5, 10, 20, or 31.5 MPa. Design number is 50.
View DA Series Pilot Operated Unloading Valve Specifications
Where it fits
The DA Series is used in hydraulic circuits that need pressure-controlled unloading. This includes systems with accumulators, where the pump should unload once the accumulator is charged, and dual-pump systems, where one pump unloads when the other takes over the flow demand.
The valve mounts on a subplate or manifold. The mounting surface must be flat and clean, and bolts should be tightened evenly to avoid distorting the valve body.
About the manufacturer
The DA Series is produced by Shijiazhuang Laiye Import & Export Trading Co., Ltd., part of Hebei Onederful Hydraulic Technology Co., Ltd., founded in 1988. OEM customization is available with drawings and specifications.
