AREA OF APPLICATIONS

The N.G.D shock prevention valve prevents the occurrence of water hammer when: –

  • The entire pump station trips.
  • The last of the running pumps trips.
  • A pump operator abruptly switches the last running pump.

UNIQUENESS

The N.G.D shock prevention system is a unique solution for high-pressure vertical or inclined pumpingsystems. The N.G.D valve can open instantaneously to prevent the water hammer occurrence.

COLUMN DRAINING

The N.G.D shock prevention valve is used as the column drain valve, enabling a cavitation-free draining of the pump discharge column.

PRINCIPLE OF OPERATION

The N.G.D shock prevention valve instantaneously opens on pump’s trip occurrence, to enable a flow passage to the station’s reservoir and as a result to avoid abrupt stoppage of the reversing flow, with no need for actuators, pilots, sophisticated instruments or an external power source.

THE CONTROL SYSTEM

The control system consists of a: –

  • N/O timer switch closes on pump’s trip occurrence and reopens after a short interval.
  • N/C Solenoid valve, causing the instantaneous opening of the shock prevention valve when the timer switch closes.
  • The N/C solenoid valve closes after a short time interval and fluid entering slowly to the valve’s closing compartment causes the slow closing of the shock prevention valve.