Maintenance
104
89217391 Rev. A
©2022 nVent
11.4.3 Checking of the expansion vessel
Expansion vessel
(Example)
Perform pressure and leak testing in accordance with the maintenance plan.
For
leak testing
of the expansion vessel proceed as follows.
1.
Take off the cap of the expansion vessel gas valve.
2.
Briefly open the gas valve. If liquid escapes, the diaphragm of the expansion
vessel is defective.
3.
Replace the expansion vessel, if necessary contact the unit manufacturer.
For
pressure testing
of the expansion vessel proceed as follows.
1.
Close the shut-off valve upstream of the expansion vessel.
2.
Have a vessel ready to collect the liquid that flows out.
3.
Open the drain at the expansion vessel and allow the medium to flow into
the collecting vessel.
4.
Take off the cap of the expansion vessel gas valve.
5.
Connect the adapter with the pressure gauge and measure the gas
pressure.
Monitor the system pressure according to the "Technical data" section.
6.
If necessary allow gas to escape or top up with gas.
CAUTION
Risk of injury - the expansion vessel is under pressure!
The expansion vessel in the unit is under pressure when the unit is switched off
and depressurised.
When working on the expansion vessel, exercise extreme caution.
NOTE
After maintenance, ensure that the drain valve of the expansion tank is closed
and the shut-off valve in the system is open.
This ensures the correct operation of the expansion tank.
Otherwise, the pressure in the system increases, the safety valve opens and the
cooling medium escapes.
