03 04

PNEUMOSTOP® Pump Overrun Valve

The Pneumostop is a pump overrun valve  – designed to detect when a double diaphragm or air driven piston pump overruns, and shuts the pump down before damage occurs to the diaphragms due to running over-speed (Runaway).  A runaway  can be triggered by lack of product or line failures.  Designed-in adjustable levels of sensitivity eliminates the nuisance of tripping  due to cavitation, that causes pumps to dive periodically..

Operating Principle

The Pneumostop is fitted into the air supply line to the pump and is set up to the optimum pressure and flow. When the pump overruns the Pneumostop detects the drop in pressure and the valve closes therefore stopping the air supply to the pump.  When armed the Pneumostop has a permanent air output signal available which is equal to the supply pressure to the pump.  This output can be used to indicate a healthy operating state, or pump enabled status.  This output is lost when a runaway is detected.



  • Day Tanks
  • Fuel storage tanks
  • Flash tanks
  • Condensate receivers
  • Cooling towers
  • Low  alarm for single tank entry

Standard models have:

  • Manual push button start
  • Adjustable sensitivity
  • Long Working life
  • Alluminium Body
  • Available in ½ and ¾ BSP Sizes
  • Pressure Range to 2 bar to  8 bar
  • Temperature Range 0-50C
  • Sensative adjustment
  • Interlock Signal
  • Air pilot remote start
  • Air pilot remote start & stop
  • Electrical remote start
  • ATEX Approval
  • Paint Pumping
  • Ink Pumping
  • Food or Beverage Holding tanks
  • Laundries
  • ATEX approved versions available for use in Class II 2 G Environments