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How to install an expansion valve for refrigeration?

Thermostatic expansion valves are an integral part of your refrigeration unit. They are responsible for ensuring the right dosage of refrigerant is entering the cooling coil to ensure maximum efficiency in the air conditioning of the system. 


These special expansion valves come with a temperature sensor that is mounted at the end of the evaporator coil. They incorporate signals from this sensor to maintain the required temperature of the HVAC system. The thermostatic expansion valve works like a precision device that can regulate the measurements of the liquid refrigerant that flows into the evaporator of your system. This regulation in the flow of the refrigerant is essential to prevent the reverse flow of the refrigerant into the compressor of your system. 


Through this mechanism, the thermostatic expansion valve successfully separates the high and low pressure sides of the refrigeration/air conditioning system. The liquid refrigerant enters the expansion valve because it is under high pressure, this pressure is reduced by the expansion valve when it reduces the amount of refrigerant entering the evaporator of the system.

Thermostatic Expansion Valve Installation


You must follow the following steps carefully to install the expansion valve successfully:


  1. All valve fittings and exterior parts of the system should be thoroughly cleaned before you begin the soldering or brazing process. This will prevent any debris from encroaching upon the refrigeration system. 
  2. You must wrap a wet cloth around the thermostatic expansion valve to protect the expansion valve from extra heat. This wet cloth will give the system a good ⅓” to ½” protection, ensuring that the soldering or brazing torch is aimed away from the expansion valve. 
  3. It is imperative to not use excessive solder or flux during the process as the excess might flow into the expansion valve and prevent its efficient operation. 
  4. The expansion valve usually comes with a sensing bulb which can control the thermostatic expansion valve. This bulb should be clamped to the suction line of the refrigerant so that it can monitor the temperature of the system. 
  5. The thermostatic expansion valve should be installed close to the air conditioning or heat pump.
  6. If your expansion valve uses an external pressure equalization ability, this equalizing pressure line should be connected with the suction line, right after the temperature sensing bulb that is installed with the thermostatic expansion valve. 
  7. The thermostatic expansion valve is only responsible for the flow of the refrigerant into the evaporator, it cannot control several other variables in the system like the temperature, head pressure, suction pressure, capacity and humidity in the system. Any attempt to use the expansion valve to regulate any of these other factors can cause compressor failure or an overall reduction on the performance of the system.
  8. This might not be the most convenient step for all, but it is advised to install the expansion valve in a vertical and upright position. This makes it easier to service the expansion valve. If you install the expansion valve in a horizontal position, you will have to reassemble the internal parts of the system to prevent damage to them during the maintenance process.  


Finding the right thermostatic expansion valve can be a tedious process. PartsFE has curated some of the best kitchen equipment parts on their online catalogue which you can find here. PartsFE delivers equipment in safe and elegant packaging. We offer same day shipping services as well so that you don’t have to miss even a day of working with your own equipment. You can follow PartsFE via social media handles on Twitter and Facebook. You can also write to us about your requirements at contact @ [email protected] or call us at +16302812419 to find the best kitchen equipment parts online. 

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