7 | Installation
Installer reference guide
48
RZAG71~140N
Sky Air Alpha-series
4P695307-1A – 2024.02
7.5.4 To check for leaks
NOTICE
Do NOT exceed the unit's maximum working pressure (see "PS High" on the unit
name plate).
NOTICE
ALWAYS use a recommended bubble test solution from your wholesaler.
NEVER use soap water:
▪ Soap water may cause cracking of components, such as flare nuts or stop valve
caps.
▪ Soap water may contain salt, which absorbs moisture that will freeze when the
piping gets cold.
▪ Soap water contains ammonia which may lead to corrosion of flared joints
(between the brass flare nut and the copper flare).
1 Charge the system with nitrogen gas up to a gauge pressure of at least
200kPa (2bar). It is recommended to pressurize to 3000kPa (30bar) in order
to detect small leaks.
2 Check for leaks by applying the bubble test solution to all connections.
3 Discharge all nitrogen gas.
7.5.5 To perform vacuum drying
NOTICE
▪ Connect the vacuum pump to both the service port of the gas stop valve and the
service port of the liquid stop valve to increase efficiency.
▪ Make sure that the gas stop valve and liquid stop valve are firmly closed before
performing the leak test or vacuum drying.
1 Vacuum the system until the pressure on the manifold indicates −0.1 MPa
(−1bar).
2 Leave as is for 4-5minutes and check the pressure:
If the pressure… Then…
Does not change There is no moisture in the system.
This procedure is finished.
Increases There is moisture in the system. Go
to the next step.
3 Vacuum the system for at least 2hours to a manifold pressure of −0.1 MPa
(−1bar).
4 After turning the pump OFF, check the pressure for at least 1hour.
5 If you do NOT reach the target vacuum or CANNOT maintain the vacuum for
1hour, do the following:
▪ Check for leaks again.
▪ Perform vacuum drying again.