Leak detection for chiller tubes is a simple process to identify which tubes are leaking.
Leak signs in chillers are many, the simplest one is the sudden pressure drop in the refrigerant circuit which can be monitored from the chiller's monitoring screen.
It is recommended to do eddy current test for the condenser tubes on yearly basis and every three to five years on evaporator tubes in order to catch any possible failure and close the eroded tubes before being leaked and therefore you can save the refrigerant which will be lost in case of leak, since it will be mixed with water and therefore couldn't be used again. In centrifugal chillers, the amount of refrigerant can go up to 1000 kg which costs around 5000 $.
However, In some cases tube leaks can't be avoided due to tube damages which may result from sharp particles that enters the system, especially from the open condenser circuit. And since We already did eddy current test short time before, I preferred to save money and detect the leaking tube by pressurizing the refrigerant circuit with air or nitrogen.