1. Build the system pressure with dry nitrogen to approximately 10 psig. Higher pressures are required for other systems depending on the refrigerant type and type of chiller. Refer to relative SOP. Never pressurize the system exceed 90% of the safe working pressure for the component with lowest pressure.
2. Check leakage for all the connections and joints with patient. Leakage detector should in good condition and leak checking time should be sufficient.
3. To check the leakage in the evaporator and condenser (water system), open the vents in the evaporator and condenser heads/water boxes and test for the presence of gas. If no leakage is present, the tubes and tube sheets may be considered tight.
4. If leakage is detected at the vents, the heads/water boxes must be removed, and further leakage checking and repair is required.