leak testing refrigeration system

Refrigeration System Leak testing (Leaks Testing)

After the systems installation work, connection of the pipe line between the indoor unit and outdoor units (for the type of split AC system) or the connection of all components of the refrigeration, the next step is the process of checking installation pipe joints leaks.

leak testing refrigeration system
leak detector

That is ensuring that the refrigeration system is completely isolated from the surrounding environment.

Some professional technicians, do this leak testing with the method of "vacuum"  the system is vacuumed to near absolute vacuum which is -30inHg or -1atm and left for some time.

If the needle or number does not move from the lowest vacuum point, the technician ensures that there are no leaks in the refrigeration system.

Some of them use the "pressurize system" method, which is a system that is pressured to more or less 10% from the maximum working pressure limit. The media used to pressurize generally use Nitrogen Gas.(N2).

Which of the two techniques is better?

Maximum vacuum working pressure is -1atm (-14.7psig). So if you use the vacuum method, only large (big) leaks can be detected, namely leakage in the category of difference in working pressure and the environment is relatively small.

If you use the "pressurize system" technique then all ranges of work pressure will be exceeded so that if no leakage occurs with this method it is certain that the system will work safely (ensure that the system has absolutely no leakage).

So actually vacuum is not the best way to leak testing. In addition, if you use a vacuum technique, if there is a leak, the air will enter the refrigeration system, which should be avoided to prevent contamination with the lubricant.

Besides that it can cause internal corrosion of the refrigeration system(pipe) and can also make the filter drier reach the saturation point which if the filter is not replaced then reduces the ability to absorb residual moisture that cannot be removed during the vacuum process.

The vacuum process aims to remove air and other gases contained in the refrigeration system so that when the refrigerant has been filled in the system they will not be contaminated.

So the steps taken should be like this.
Piping installation and components, flushing the refrigeration systems with nitrogen(N2) gas (cleaning of refrigeration system paths) > installation of filter or driers > leak testing with Nitrogen gas > evacuating / vacuum (-14.7 PSIG)> refrigerant contents > test run > performance analysis and check all parameters.

( Wich is better inverter ac or non inverter AC)

Note: for complex systems the flushing process can be done in stages during the installation work.

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