The basis for all Caltherm thermostatic products are thermal actuators, created from a temperature-sensitive expansion material that transforms thermal energy into mechanical energy using the expansion of material from its solid state to its liquid state.
Caltherm's flat diaphragm elements, which are known for extreme accuracy and repeatability, entrap temperature sensitive expansion material in the cup. As the material expands, the energy is transferred through the diaphragm and plug, exerting pressure on the piston. This energy creates movement of the piston through the guide. Upon cooling, the forces of the return spring result in the return of the piston, plug and diaphragm to their initial position.
Similarities between the flat diaphragm and squeeze push elements include the use of temperature sensitive expansion material and a return spring to achieve initial positioning. However, one major difference is the additional power stroke the squeeze push can provide over the flat diaphragm. This is accomplished through the use of the compression on rubber bag, which then moves the piston with a lateral squeeze and a vertical push.