Flushing The Refrigerant Piping - LG Tri-Zone Multi F Installation Manual

F
MULTI
F
MULTI MAX

Flushing the Refrigerant Piping

Flushing is a method of cleaning the refrigerant piping using pres-
surized nitrogen gas. Flushing:
1. Removes oxidation bubbles that may have formed inside the
copper piping if nitrogen replacement was insufficient during
soldering.
2. Removes foreign material and moisture from piping if the piping
wasn't stored properly.
3. Checks connections in pipes linking outdoor and indoor units
(both liquid and gas pipes).
Flushing the Refrigerant Piping Procedure
1. Attach a pressure regulator on a nitrogen cylinder.
2. Connect the charge hose from the pressure regulator to the
outdoor unit liquid piping side service port before its connection
to the indoor or BD (Multi F MAX systems only) unit piping.
3. Open the main valve on the nitrogen cylinder and set the pres-
sure regulator to 0.5 MPa (72.5 psi).
4. Verify that the nitrogen is flowing through the piping correctly.
5. When flushing, block the open end of the piping with a wood
insulation block. When the pressure becomes too high, quickly
remove the block.
6. Repeat steps 4 and 5 until the piping is completely flushed and
clean.
7. Connect the charge hose from the pressure regulator to the out-
door unit gas piping side service port before its connection to the
indoor or BD (Multi F MAX systems only) unit piping.
8. Follow steps 3, 4, 5, and 6.
9. For systems with BD unit(s) (Multi F MAX only), each piping run
should be flushed individually before connecting the indoor units
(follow steps 3, 4, 5, and 6).
REFRIGERANT PIPING PREPARATION
Due to our policy of continuous product innovation, some specifications may change without notification.
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Flushing the Refrigerant Piping
Figure 53: Flushing the Refrigerant Piping.
Primary
Side
Secondary Side (72.5 psi)
Lo Hi
Pressure Regulator
Nitrogen
72.5 psi
W ood Insulation
Lo Hi
Taping
Nitrogen
41