What is inside of capillary thermostat

Capillary thermostats are an essential component of various heating and cooling systems. They play a crucial role in maintaining a desired temperature by controlling the supply of heat or cold. But have you ever wondered what is inside a capillary thermostat? Let’s delve into the workings and components of this important device.

At the heart of a capillary thermostat is the temperature sensor, which is comprised of a capillary tube, a diaphragm, and an expansion fluid. The capillary tube is a thin, flexible tube made of materials that can withstand temperature variations. It acts as a conduit for the expansion fluid, allowing it to circulate and transmit temperature changes to the diaphragm.

The diaphragm serves as a connection between the capillary tube and the rest of the thermostat assembly. It is a flexible membrane that moves in response to pressure changes caused by the expansion of the fluid. When the temperature sensor detects a rise in temperature, the expansion fluid heats up and expands. This expansion exerts pressure on the diaphragm, causing it to move.

The movement of the diaphragm is critical for the functioning of the capillary thermostat. It is equipped with electrical contacts that open or close depending on the position of the diaphragm. As the diaphragm moves due to the pressure exerted by the expansion fluid, it either completes or interrupts an electrical circuit.

In simple terms, when the temperature rises beyond the desired set point, the expansion fluid in the capillary tube expands, exerting pressure on the diaphragm. This pressure causes the electrical contacts to open, interrupting the supply of heat or cold to the system. As a result, the temperature starts to decrease. Conversely, when the temperature falls below the set point, the contraction of the expansion fluid relieves pressure on the diaphragm, causing the electrical contacts to close and restore the supply of heat or cold.

Capillary thermostats are commonly used in appliances such as refrigerators, ovens, and HVAC systems. Their reliability and accuracy in controlling temperature make them a popular choice in various industries. The use of a capillary tube and an expansion fluid allows for precise temperature sensing and control, ensuring that the desired temperature is maintained consistently.

In conclusion, a capillary thermostat is a sophisticated device that relies on the interaction between a capillary tube, a diaphragm, and an expansion fluid to regulate temperature. The expansion of the fluid and its impact on the diaphragm enable the opening or closing of electrical contacts, controlling the supply of heat or cold. 

capillary thermostat

Post time: Sep-08-2023