Galletti LCA Series Installation, Use And Maintenance Manual page 23

LCA
TIGHTNESS TEST
Fill the circuit with anhydrous nitrogen supplied from a tank with a pressure-reducing valve until the
pressure rises to 10 bars.
During the pressurisation phase, do not exceed the pressure setting of the safety valves;
otherwise you will cause the latter to open.
The presence of any leaks must be determined using special leak detectors. Should any leaks be detected
during the test, empty out the circuit before repairing the leaks with suitable alloys.
Do not use oxygen in the place of nitrogen as a test agent, since this could cause a risk
of explosion as well as the certainty of extensive oxidisation in high-temperature areas.
HARD VACUUM AND DRYING OF THE COOLING CIRCUIT
To achieve a hard vacuum in the cooling circuit it is necessary to use a pump capable of generating a
high degree of vacuum, i.e. 15 Pa of absolute pressure.
If there is no suitable vacuum pump available, or whenever the circuit has remained open for long
periods of time, you are strongly recommended to adopt the triple evacuation method. This method is
also recommended when there is a presence of humidity within the circuit.
The vacuum pump should be connected to the inlets.
The procedure to be carried out is as follows:
- Evacuate the circuit until you reach an absolute pressure of at least 35 Pa: at this point inject nitrogen
into the circuit until you reach a relative pressure of about 1 bar.
- Repeat the step described above.
- Carry out the step described above for the third time, but in this case attempting to reach the hardest
vacuum possible.
Using this procedure you can easily remove up to 99% of pollutants.
RG66000986 – Rev.00 23