Daikin VRV II Series, Design, Installation & Testing Instructions, Page: 26 / 242

Installation Si39-303
20 General Information
Refrigerant Pipe
Flushing
[3 major effects]
1. Removal of oxidation bubbles formed inside copper pipes when “nitrogen replacement is insufficient”
during soldering work
2. Removal of extraneous material and moisture from pipes when covering has been insufficient
3. Checks connections in pipes linking outdoor and indoor units (Both liquid and gas pipes)
[Example of procedure]
1. Set pressure regulator on nitrogen cylinder.
∗
The gas used must be nitrogen.
(There is a danger of condensation if fleon or carbon dioxide are used and oxygen carries the risk of
explosions.)
2. Connect the charge hose from the pressure regulator to the service port on the liquid pipe side of the
outdoor unit.
3. Fit blanking plugs to all indoor units (B) other than unit A.
4. Open the main valve on the nitrogen cylinder and set the pressure regulator to 0.5MPa.
5. Check that the nitrogen is passing through the unit A liquid pipe.
6. Flushing.
!
Block the end of the pipe with the insulation of your hand.
↓
!
When the gas pressure becomes too great to contain remove insulation quickly. (First flush)
↓
!
Block the end of the pipe with insulation again.
↓
(Carry out second flushing)
Flushing is a method of cleaning extraneous matter out of pipes using pressurized gas.