The Common Causes Of Refrigerant Leaks And How To Fix Them


Refrigerant leaks are not a topic that is spoken about regularly, but when it does arise these leaks need to be taken seriously.  Many professional technicians deal with refrigerants on a large scale, such as in department stores, and put certain preventative measures in place to keep problems to a minimum.  This article will provide information on the common causes of refrigerant leaks and how to fix them.

  1. Flares And Flare Nuts

While the majority of refrigeration equipment is moving away from valves, many original machinery continues to use the flare system with flare connections.  Since the flare connection is created with hand-made items, meaning without proper tools, the results of a flare will vary dependent on the refrigerant.  For example, what may have seemed to be an inferior flare in one item could be suitable in another.  Unfortunately, this variation influences the quality of the flare joint or nut as well; making it dependent on the person who installs the refrigerant.  A dilemma arises when the refrigerant leaks, but it is possible to repair the issue by replacing the delicate nut with a suitable flare joint.

  1. Flares That Are Too Small Or Thin

When the surface area of the flare is too small as compared to the mating surface, there will be insufficient support by the flare nut to generate a good sealant.  As a result, this ineffective flare joint will become a refrigerant leaking area.  While most technicians will attempt to over-tighten the joint as a repair, which can be beneficial, this is only a temporary solution.  The small nature of the flare surface will cause it to fail regardless of the tension; therefore, it is important that technicians consider the depth of the flare to ensure a perfectly sized flare is available.

Flares can also be considered too thin and this occurs when the tubing of the flare tool is insufficient to form a “good” flare.  To repair this cause of refrigerant leak, it is recommended that copper be added to the flare; thereby, increasing the diameter of the flare.  Unfortunately, the thin flare could stress the copper if it is too thin and this can result in further damage to the flare joint.

  1. Over-Tightening Of The Flare

Due to the fact that over-tightening is a subjective term, many technicians use flare connections with tightening measurement specifications for the joints.  Not only does this offer a minimum tightening guideline to ensure the connection remains leak free, but it will also offer a maximum guideline ensuring the joint is not damaged.  When new flare connections are installed, a leak check must be done using 550 psi dry nitrogen.  This will assist with evacuation procedures and verifying that flare joints remain refrigerant leak free.

  1. Sealants On Threads

It is always advised that one check with the equipment manufacturer to view the use of sealant on flare threads.  While the use of sealant can be considered a resolution to many refrigerant leak issues, it is also possible for sealant to be a problem when used incorrectly.

  1. Missing And Leaking Schrader Caps

The Schrader valve or cap is a method of temporarily accessing the system to charge the unit or measure the system’s pressure.  If the valve or cap is missing or damaged, the equipment can experience refrigerant leaks.  Soap bubbles can help to verify if the valves are leaking, and if they are leaking it would be best to replace them.  The cap, however, is another issue altogether.  If a cap is missing, then you may not need to replace the item immediately.  A missing cap is often a case of laziness in installation, but you can be certain that the missing cap will become a leak in the near future.  The best thing to do in these situations is repair the valves or caps.

  1. A Missing Or Loose TEV Adjustment Cap

Another type of cap present in refrigerant equipment is the TEV adjustment cap.  While a seal exists between the valve body and the TEV adjust stem, one of the two seals prevent the refrigerant in the system from leaking.  The second cap, also known as the seal cap, is considered to be the cap ensuring the TEV does not experience a seal leak.  To eliminate leaks, it is important that the cap is tightened around the stem and opposing notches in the thread be sealed effectively.  Professional tools are required to complete this task, particularly if the seal cap is missing.  If the seal cap is missing, it is necessary to replace it immediately.

  1. A Leaking Elastomer Seal

Needless to say, seals deteriorate over time because of heat, age, and over-tightening.  It was reported in previous years that elastomer seals would swell when refrigerant was used, but they are noted to swell more when chlorinated refrigerants are utilized including R22 refrigerant.  A swelling and shrinking sensation will result in the seals becoming damaged; therefore, leading to leaks in refrigerant.

To deal with this issue, it is recommended that the refrigerant is removed and new refrigerant along with new elastomer seals.  This will ensure that the new refrigerant implemented during a refrigerant conversion is not being met with old, damaged seals.  By having everything new, it is possible to improve the efficiency of the equipment and reduce the chance of leaks.

  1. The Use Of Copper Tubing

The final, and somewhat surprising, cause of refrigerant leaks is the use of copper tubing in systems that use refrigerant.  When copper material is used to restore clamps that have become loose, it is likely that the metal will wear a hole in the system’s tubing.  The vibrations experienced by the equipment will rub against the strut and this contributes to the wear and tear.  One method of eliminating these tubing leaks is by periodically inspecting the clamps to ensure they are tightened.  Moreover, you can use cushion-style clamps with rubber instead of copper to avoid further wear and tear.

As can be seen, there are many common causes and ways to find refrigerant leaks ranging from the use of copper tubing to over-tightening of flare connections.  By using the information above, you can identify the cause of refrigerant leaks and how to resolve the issue.