CAPSTAT Capillary Thermostat CT

Temperature control of Heat Trace circuits in SAFE areas only.

  • Three wide span temperature ranges.
  • Stainless steel sensor and capillary tube.
  • Optional stainless steel armoured capillary.
  • Optional over-temperature lock-out.


  • Capstats are temperature adjustable ON-OFF thermostats comprising a liquid filled sensing bulb connected to an electrical contactor switch, via a capillary tube.
  • Expansion of the liquid on rise in temperature causes the contactor switch to open, removing power from the heating circuit. As a liquid cools, the switch closes, energising the heater(s).
  • Capstats may control surface temperatures such as pipes or vessels. Alternatively, the sensing bulb may be positioned to sense the air temperature.
  • Capstats may be used to provide process temperature control in safe areas, by switching the heating circuits at the desired temperature.
  • The addition of a high limit cut-out switch (as provided with the Capstat-Dual version) is specified when the heat tracing scheme will not stabilise at a safe temperature without process control. The high limit cut-out switch will operate if the process control switch fails, or if an unsafe process temperature occurs.


  • CT - Capstat for use in safe areas.
  • CT../X - Optional armoured capillary provides additional mechanical protection for the capillary tube(s). 
  • CT..DUAL - Over-temperature lock-out (20°- 300°C). Factory preset - over-temperature setting
    must be supplied with the purchase order.


For certified hazardous areas, CT-FL Capstats are available
(see separate datasheet).

Product examples