Bermad 790-M Burst Control Valve



790-M – Burst Control Valve

The Model 790-M Burst Control Valve is a hydraulically operated, diaphragm actuated control valve that—upon sensing flow in excess of setting—shuts off and locks drip tight until it is manually reset.

As long as the flow is lower than the setting, the valve remains fully open, minimizing head loss.

Zone shut off at burst

  • "Older" burst susceptible networks
  • Outlets from reservoir at earthquake risk
  • Vulnerable network infrastructure facilities
  • Networks at risk of mechanical damage

The Model 790-M Control Valve is a hydraulically operated, diaphragm control valve that upon sensing flow in excess of setting shuts off and locks drip tight, until it is manually reset. As long as flow is lower that the setting, the valve remains fully open, minimizing head loss.


  • Line pressure driven - independent operation
  • Mechanical flow system
    • Field adjustable
    • No moving parts
    • Non electronic components
  • Highly sensitive hydraulic pilot
    • Requires minimal valve
    • Tight setting window
  • In-line serviceable - Easy maintenance
  • Double chamber
    • Moderated valve reaction
    • Protected diaphragm
    • No spring - Full opening
  • Flexible design - Easy addition of features
  • "Y" or angle, wide body - minimized pressure loss
  • Obstacle free, full bore - Uncompromising reliability

Major Additional Features

  • Closing at pressure drop - 790 - 91.Pressure reducing - 792 - U
  • Solenoid control - 790 - 55- M
  • Electric override - 790 - 59 - M



The Model 790-M is a pilot controlled valve equipped with an adjustable, 2-way, high sensitivity, differential pressure sustaining pilot.

The pilot, sense valve differential pressure.

Should that pressure sire above pilot setting, the pilot opens, introducing upstream pressure into the upper control chamber, causing the main valve to begin an irreversible "close & lock" process.

Opening and resetting the main valve requires manual intervention by means of the manual reset valve.

When differential pressure is below pilot setting, the pilot blocks upstream pressure from the control chamber, and the main valve remains fully open.

The manual test valve enable simulation of burst conditions and valve response. After testing, reset procedure is required.

The mechanical flow stem enables adjusting the closing point, to meet various flow regimes.



790-M-BURST-CONTROL-VALVE 790-M – Burst Control Valve Brochure