keyword:Hydraulic Remote Control Valve, unloading relief valves, pressure control valves
These unloading relief valves are used to operate the pumps with minimum load in accumulator circuits or in high-low pump circuits. In accumulator circuits, when the system pressure reaches to a cut out pressure (adjusted maximum), the valve acts to divert the pump delivery to the reservoir at low pressure, thus the pump is unloaded automatically. When the accumulator pressure drops to the cut in pressure (refer to characteristic chart on page 5), the valve directs the pump delivery to the accumulator and hydraulic system. An integral check valve prevents reverse flow through the valve from the accumulator. In high-low pump circuits, the valve acts to unload the large volume pump with the same manner as described above during load operation of the small volume pump.
Recommended Viscosity and Oil Temperatures
Viscosity ranging between 15 - 400 mm2/s (77 - 1800 SSU).
Oil temperatures between -15/+700C (5 - 158°F).
Use hydraulic fluids which satisfy the recommended viscosity and oil temperatures given above.
Control of Contamination
Due caution must be paid to maintaining control over contamination of the hydraulic fluids which may otherwise
lead to breakdowns and shorten the life of the valves. Please maintain the degree of contamination within NAS
1638-Grade 12. Use 25 µm or finer line filter.
Instructions
To adjust the pressure, loosen the lock nut and turn the pressure adjustment handle slowly clockwise for higher pressures or
anti-clockwise for lower pressures. After adjustments, do not forget to tighten the lock nut.
Take care not to neglect connecting the drain pipe to the tank; otherwise not only will the valve fail to operate properly but
also the line pressure will rise infinitely.Extend the end of the drain pipe into fluid.
Limit the pressure drop between the valve and the accumulator in an accumulator circuit below 10% of the
cut-out pressure.
Limit the drain port back pressure below 2% of the cut-out pressure.
Shijiazhuang Hanjiu trade Co., Ltd bring lots of the high-standarad equipments and technology of Hydraulic production in the year 2003, specializing in the Hydraulic production.
The company mainly produces hydraulic components like Hydraulic valves, oil cylinders, pumps and systems. All of these hydraulic components can be widely used for mining, metallurgy, steel, chemical industry, enginnering, rubber and plastic, papermaking, agricultural machinery hydraulic oil cylinder, machines and hydraulic systems.
