CC7.8.9/0519/E
2/7
3
Pressure resistance test and leak test
CAUTION
The system must be properly evacuated before filling the cooling circuit with refrigerant.
This should result in a reduction of the residual moisture content to approx. 50 ppm.
Evacuation should be carried out to less than 3 mbar and, if necessary, the vacuum
should be broken with dried nitrogen.
Depending on the installation, pressure strength tests and leak tests must be carried out on different pressure
layers. The shut-off of system sections may be necessary.
Several shut-off devices are installed in the CO
2
refrigeration unit. These are suction and pressure shut-off
valves of the compressor, high-pressure control valves at the gas cooler outlet, flash-gas bypass valves
between the liquid receiver and suction line, shut-off valves at the liquid receiver and shut-off valves in the
liquid line at the outlet from the refrigeration unit.
It is the responsibility of the user to decide which barriers are to be opened/closed in order to carry out the
pressure tests. For the evacuation process, it is recommended that all shut-off devices be opened and
evacuated from both sides via the connections on the suction side and the connection on the liquid receiver.
The shut-off valves at the discharge port, on the suction side of the compressor, at the outlet of the liquid
receiver and the shut-off valve in the liquid line can traditionally be operated manually.
To open the high-pressure control valve and the flash-gas control valve, please follow the instructions in
section 4 next page.
Figure 2: Shut-off valves in the CO
2
refrigeration unit
Position
Description
1
Copeland Stream
compressor
2
Discharge mufler
3
Gas cooler/condenser
4
Flash tank
5
Filter-dryer
6
Sight glass
7
Ball valve
8
OW5 oil watch
9
Pressure relief valve
HPV
High pressure valve
BPV
Bypass valve
HP
High-pressure limiter
INV
Compressor inverter
B1
Suction pressure
B2
Discharge pressure
B3
Liquid receiver pressure
B4
Suction gas temperature
unit
B5
Suction gas temperature
compressor
B6
Discharge line temperature
B7
Gas cooler temperature
B8
Oil temperature
B9
Ambient temperature
B10
Cabinet temperature
