Temperature Control Element Diaphragm TWG

Frost protection, refrigeration thermostat, safety switches,
hot air sensors, temperature bellows with little space requirement.

Technical design:

Temperature based volume expansion of the charge, results in a displacement of the diaphragm. Displacement is mainly used as a constant control or switching function in connection with electronic or electro-mechanical components. Diaphragm systems can also be used as direct mechanical actuators. In case of a leakage, diaphragm moves into a neutral position which may also be used as a safety function. Maximum actuator force depends on geometry and on the charge itself.


  • Charges: fluid, gas, refrigerants, mixed phases
  • Compact design
  • Expansions from 0.005 up to 0.10 mm/K
  • Suitable for temperature ranges from -35°C up tos + 340°C
  • Linear characteristic
  • Pressure or displacement limitation (only gas, refrigerant and mixed phases charges)
  • Safety function
  • Own diaphragm production


Stainless steel (diaphragm + housing, copper and brass, various layers on request.

Testing, Tests, Simulation
System-oriented testing.
All of the EGELHOF products are tested in our state of the art simulation and test benches during product design.
These test installations are also offered as an external service.