ThermaFlex Plate Heat Exchangers

Ancillary Items & Options

  • Control Valve: The control valve should be 2-port for steam and 2 or 3-port for water primary. A 3-port valve will maintain a fairly steady flowrate in the primary pipe-work whether the calorifier is using the primary water or not - this may be required on some systems. Control valves with a "double seat" to give higher throughput do not give guaranteed shut-off and should not be used for calorifier control.
  • High Limit Valve: If the control valve fails in the open position the calorifier will overheat. A high limit valve prevents this by shutting the primary fluid off if secondary temperature is excessive.
  • Pressure Relief Valve: Needed for all unvented calorifiers and where working pressure exceeds 25 m w.g.
  • Automatic Air Vent: Normally only needed on unvented systems.
  • Expansion Vessel: An expansion vessel should be connected to the cold feed pipe of unvented calorifiers.
Information Pages


     Primary Heat Source

     Some System Considerations

     Ancillary Items

     Thermal Insulation

     Design Standards

     Unvented Packages

     WRAS Approval 

Technical Documentation

     Download Data Book

     Download O&M Manual

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