What You Need To Know About The A/C Expansion Valve


The A/C expansion valve is present in every air conditioning unit, whether it is designed for automobiles or buildings. Its primary purpose is to alleviate refrigerant pressure, and though the device seems simple given that it has few moving parts, it is a necessity and the A/C system will not function without it.

How Auto A/C Systems Function

Most vehicular A/C units are divided into two parts, which are an elevated pressure side, and a lower pressure side. The high or elevated pressure side begins with a compressor and terminates near an expansion valve while the lower pressure side begins with an expansion valve then terminates near the compressor. As you can see, while the devices are similar, they have opposing tasks which are used to increase or decrease pressure. However, many inquisitive drivers want to know why they need to boost refrigerant pressure if it will eventually fall to the lower pressure state?

The purpose of performing this process is to allow your air conditioning unit to utilize the inherent cooling effects which come from allowing the higher pressure fluid to rapidly decompress. To understand how this works, take a spray paint can that is full and empty it quickly. While doing so you may notice that it becomes cooler in the palm of your hand. Vehicle expansion valves operate in a similar manner. Rapid refrigerant decompression causes it to cool by as much as thirty two degrees, and afterward, it can be transferred to an evaporator where it can cool down the interior air.

What Happens If The Expansion Valve Malfunctions?

As stated previously, your expansion valve is a crucial component and any malfunction on its part would quickly make the A/C system unusable. The reason for this is that the valve usually consists of a miniature opening which makes it susceptible to clogging. Under normal circumstances, this shouldn’t happen; because most automobile A/C systems are closed meaning that it is quite difficult for external debris to get in.

However, it is possible for an expansion valve to become clogged if system leaks are present and exposed to the atmosphere because contamination might occur. Another method by which expansion valve clogging could occur is if the compressor becomes worn and releases particles or if you add poor quality refrigerant.

Why You Should Avoid Using Cheap Leakage Stop Products

A lot of drivers are worried about air conditioning leaks and this is understandable as this is one of the most common A/C issues that they run into. However, the trouble with using cheap leakage stop products is that they are comprised of miniature particulates which although designed to clog leaks and keep the refrigerant retained, might also clog up the expansion valve. To check and see if your expansion valve has become clogged, you’ll want to measure pressures around the system and watch for elevated pressure that is abnormally high in the higher pressure side that is accompanied by inadequate cooling.

Why Choose R & Y A/C Compressors?

Our business has been providing quality parts and services to clients in the air conditioning parts industry for more than 30 years. We specialize in air conditioning and heating systems for a variety of vehicles. We are conveniently located in North Miami Beach, Florida. We have several warehouses meaning we can quickly process and ship orders anywhere in the United States and abroad. Contact us today!