Bermad 735-M – Surge Anticipating Control Valve



735-M – Surge Anticipating Control Valve Watermark & AS5081

The Model 735-M Surge Anticipating Valve is an off-line, hydraulically operated, diaphragm actuated valve. The valve, sensing line pressure, opens in response to the pressure drop associated with abrupt pump stoppage. The pre-opened valve dissipates the returning high pressure wave, eliminating the surge.

The Model 735-M smoothly closes drip tight as quickly as the relief feature allows, while preventing closing surge. The valve also relieves excessive system pressure.

  • Eliminates surge in all pumping systems:
    • Booster & deep well, single & variable
  • Eliminates surge in all distribution networks:
    • Municipal, high-rise buildings, sewage, HVAC, irrigation
    • Difficult to maintain, remote locations, and older systems


  • Replaces surge air vessels
    • Relieves surge, fail-safe open
    • Minimal maintenance
    • Economy or space
    • Lower investment & maintenance costs
    • Especially economic for higher pressure ratings
  • Line pressure driven
    • Independent operation
    • No motor required
    • Long term drip tight sealing
    • Adjustable hydraulic actuation
  • Double chamber
    • Moderated valve closing (no surges)
    • Protected diaphragm
  • In-line serviceable - East maintenance
  • Obstacle free, full bore - Uncompromising reliability
  • Balanced seal disk - High flow capacity

Major Additional Features

  • Solenoid control - 735 - M
  • Sensing diaphragm (for sewage) - 735 - Md
  • Electric override for fire protection - FP - 730 - 59
  • Quick pressure relief valve - 73Q



The abrupt stopping of a pump produces a pressure drop as the travelling column of water, with its inherent momentum, continues to travel along the line, generating severe low pressure.

When the travelling column of water losses its momentum, it travels back towards the pump. Should it hit the closed check valve, a very high pressure surge is create and travels throughout the system as a damaging wave at velocities of up to "March4" No quick relief valve can react quickly enough to eliminate it.


735-M – Surge Anticipating Control Valve 735-M – Surge Anticipating Control Valve Brochure