Unloading valves DAM

The unloading valve is used with a low pressure (LP) and a high pressure pump (HP) in a dual-pressure-system. They both supply the same working port. The valve unloads the low pressure pump flow at a set pressure to the tank. Before the switchover both pumps supply the working port. After the switch over the low pressure pump flow is connected loss-free to the tank. The working port is supplied by the high pressure pump only.

Max. operating pressure 700 bar
Max. flow rate 40 l/min
Porting NG 4

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Features Advantages
Poppet valve Good corrosion resistance
Directly operated Poppet tight
Adjustable over the entire pressure range High operational safety and reliable switching

Design

  • Poppet valve
  • Directly operated
  • The unloading valve DAM is integrated together with a check valve into avalve block
     

Technical data

Hydraulic fluid mineral oil according to DIN 51524 (other fluids on request)
Fluid temperature range -20 to 80 °C
Ambient temperature range -20 to 50 °C
Viscosity range 10 to 400 mm²/s
Porting NG 4
Max. operating pressure connection HP 700 bar
Max. operating pressure connection LP 150 bar
Pressure setting range connection LP 25 to 150 bar
Max. flow rate 40 l/min
Filtration (recommendation) according to NAS 1638 class 6 resp. ISO/DIN 4406 17/15/12
Pressure drop (LP->T) 3 bar (at 25 l/min and 32 mm²/s)
Weight see technical data sheet
Materials cartridge body: free-cutting steel
cone: hardened steel
valve body: stainless steel