Bermad WW730 Pressure Relief/Sustaining Valve



WW730 – Pressure Relief/Sustaining Valve AS5081 / WaterMark

The Model 730 Pressure Relief/Sustaining Valve is a hydraulically operated, diaphragm actuated control valve that can fulfill either of two separate functions. When installed in-line, it sustains minimum pre-set, upstream (back) pressure regardless of fluctuating flow or varying downstream pressure. When installed as a circulation valve, it relieves excessive line pressure when above maximum pre-set.

  • Prioritizing pressure zones
  • Ensuring controlled pipeline fill-up
  • Preventing pipeline emptying
  • Pump overload & cavitation protection
  • Safeguarding pump minimum flow
  • Excessive line pressure protection


  • Line pressure driven - Independent operation
  • Balanced seal disk - High relief flow capacity
  • In-line serviceable - Easy maintenance
  • Double chamber design
    • Moderated valve reaction
    • protected diaphragm
  • Flexible design - Easy addition of features
  • Variety of accessories - Perfect mission matching
  • "Y" or angle, wide body - Minimized pressure loss
  • Semi-straight flow - Non-turbulent flow
  • Stainless steel raised seat - Cavitation damage resistant
  • Obstacle free, full bore - Uncompromising reliability
  • V-Port Throttling Plug - Low flow stability

Major Additional Features

  • UL Listed and FM Approved for fire protection - FP - 730 - UL/FM
  • Solenoid control - 730 - 55
  • Quick pressure relief valve - 73Q
  • Pressure sustaining & reducing valve - 723
  • Check feature - 730 - 20
  • High sensitivity pilot - 730 - 12
  • Level control & pressure sustaining valve - 753
  • Pump control & pressure sustaining valve 743
  • Pump circulation & pressure sustaining valve - 748
  • Electrically selected multi level settings - 730 -45
  • High sensitivity hydraulic positioning - 730 -85
  • Electronic pressure sustaining valve - 738 - 03


Operation - Pressure Sustaining (In - Line)

The Model 730 is a pilot controlled valve equipped with an adjustable, 3-way pressure sustaining pilot. The needle valve continuously allows flow from the main valve inlet into the upper chamber. The pilot senses upstream pressure and should be set to minimum system pressure allowed. Should steam pressure tend to fall below pilot setting, the pilot throttles, enabling pressure to accumulate in the upper control chamber, causing the main valve to throttle, sustaining upstream (back) pressure at the pilot setting. Should upstream pressure be below pilot setting, the pilot closes, causing the main valve to close drip tight.

Should upstream pressure tend to rise above pilot setting, the pilot releases accumulated pressure causing the main valve to modulate open. The needle valve controls the closing speed. The downstream cock valve enables manual closing.


WW730 – Pressure Relief/Sustaining Valve Brochure WW730 – Pressure Relief/Sustaining Valve Brochure