McQuay MQS-24018-CFC216A Installation And Operation Manual page 46

Note：
1 The standard pipe length is 7.5m. When the length (L) of the connecting pipe is less than or equals 7.5m, there
is no need to add refrigerant. If the connecting pipe is longer than 7.5m, it is required to add refrigerant. In the
above table, the amounts of refrigerant to be added for the models are listed for each additional meter of pipe
length.
2. The pipe wall thickness shall be 0.5-1.0 mm and the pipe wall shall be able to withstand the pressure of 6.0
MPa.
3. The longer the connecting pipe, the less effective the cooling or the heating will be.
Connection of Pipeline:
(1) Align the flared end of the copper pipe with the center of the thread joint. Manually tighten the flared end
nut.
(2) Use torque spanner to tighten the flared end nut until the spanner clatters (See Fig.11-17).
Fitting Pipe for
Indoor Unit
Spanner
Fig. 11-16
The following table describes the torques for tightening nuts of different pipe diameters.
(3) The bending angle of the fitting pipe shall not be too small, and otherwise the pipe may break. Please use a
bender when bending the fitting pipes.
(4) Use sponge to wrap the connecting pipe and joint without thermal insulation, and use plastic tape to bundle
the sponge.
(5) Remove the cap of the liquid valve and the gas valve.
(6) Use an inner hexagon spanner to turn the spool of the liquid valve for 1/4 circle. At the same time, use a
screwdriver to lift the spool. Then there is discharge of gas.
(7) Refrigerant gas shall appear after the gas is discharged for 15 seconds. Now close the one way valve
immediately and tighten the bonnet.
(8) Fully open the spools of the liquid valve and the gas valve (refer to Fig. 11-17).
(9) Tighten the valve cover. Then use soap water or leakage detector to check if there is leakage at the position
where the indoor unit or the outdoor unit is connected with pipelines.
(10) If possible, use a vacuum pump to remove air out from the valve. Refer to Fig. 11-18
Flaring Nuts Fitting Pipe
Torque Spanner
Pipe Diameter
6.34mm
9.52mm
15.88mm
12.7mm
19.05mm
22.05mm
Gas Valve
Liquid Valve
Inner Hexagon
Spanner
Screwdriver
Fig. 11-17
Tightening Torque
15-30 (N·m)
35-40 (N·m)
60-65 (N·m)
45-50 (N·m)
70-75 (N·m)
80-85 (N·m)
42
One-Way Valve
Valve Cap
Valve Stem