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Pilot Operated, Spool Type, Inversely Controlled, SAE-08 Cartridge – PDB08PZ-08


The PDB08PZ is a pilot-operated, spool type proportional pressure relief valve.

If pressure at port 1 exceeds the setting defined by the electrical signal, the pilot poppet opens and oil flows from behind the main spool to tank port 2. Then, the resulting pressure differential causes the main spool to lift against the return spring and allows flow from port 1 to port 2. Therefore, as a function of the electrical signal the relief pressure at port 1 can be changed steplessly.

Furthermore, the control of the valve is invertible: with decreasing control current the pilot poppet of the valve closes, the main stage follows the pilot stage and it creates a counter-pressure at port 1.
Without its energy, the pressure is the highest pressure that has been preset (fail-safe function). Therefore, the maximum pressure can be pre-set mechanically.


  • Reduces cavitation
  • External surfaces zinc-plated and corrosion-proof
  • Good stability across the whole pressure and flow range
  • Excellent dynamic performance
  • Hardened and ground internal valve components to ensure minimal wear and extended service life
  • Low pressure drop due to CFD optimized flow path
  • Adjustable throughout flow range
  • Also, available in different versions with hydropneumatic damping and reduced overlap for the reduction of pressure peaks
Contact us for more information on this product

HYDAC Australia

HYDAC New Zealand

AUSTRALIA 1300 449 322

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