Safety Shut-Off Valves


Safety Shut-Off Valves


This Pressure Protection System is designed to protect equipment downstream of a pressure reducing station in a gas distribution system. It consists of a trunnion mounted ball valve complete with actuator and control system supplied in a self-contained and compact unit. It is installed in the pipeline, upstream of the pressure reducing station. If there is an excessive rise (PP-A Type) / rise or fall (PP-B Type) of pressure downstream of the station due to an equipment or operational malfunction, it will react by shutting off the supply of high pressure gas.


Ball Valve

  1. Trunnion mounted
  2. Two piece or three piece construction
  3. Double block and bleed in open and closed position
  4. Antistatic device
  5. Sealant injection system


  1. Double acting Scotch Yoke
  2. Yoke design optimized to give increased torque output in breakout/reseat position
  3. Low friction self-lubricating PTFE piston seals as standard
  4. Nickel plated steel alloy drive shaft and hardened steel alloy yoke assembly
  5. All bearing surfaces lubricated for life
  6. Lapped and anodized cylinder bores
  7. Acetylic resin drive shaft bearings
  8. Anodized actuator body to prevent external corrosion
  9. Weatherproof

Control Cabinet

  1. Diverter valve for balancing up and down stream pressures on the pipeline valve
  2. Filter to ensure the control components are supplied with clean gas
  3. Regulator to control the gas supply pressure to the actuator
  4. Pressure switch to provide shut down signal on sensing rising/falling downstream pressure
  5. Directional control valve, with manual push button, closes valve on receipt of shut down signal
  6. All control components are tubed together using stainless steel tube and fittings
  7. All control components are housed in a weatherproof cabinet