Carrier 53QPCT18H-708F Installation Manual page 34

CONNECTING REFRIGERANT PIPING (Cont.)
16-11 STEPS OF CONNECTING REFRIGERANT PIPING LINES TO INDOOR UNIT
Connecting gas and liquid piping lines
respectively with gas and liquid half
unions of indoor unit.
A. Lubricate flare nuts of gas and liquid piping
line end and the threads of the gas and liquid
half unions of indoor unit with anti – freeze
oil.
This is effective for reducing refrigerant
leaks.
B. For proper connection, align the centers of
gas union pipe and flare pipe straight with
each other, then finger tighten several turns
the flare nut tightly at first to obtain a smooth
match.
C. Then hold the union side with a double-ended
wrench and tighten the flare nut by applying
the tightening torque indicated in the table.
Be careful not to damage the flare nut
threads.
NOTES
1. Insufficient tightening torque
will cause refrigerant leaks.
Over tightening the torque
2.
will damage the pipe flaring
and cause refrigerant leaks.
16-12 STEPS OF CONNECTING REFRIGERANT PIPING LINES TO OUTDOOR UNIT
• Connecting the other ends of gas and liquid
piping lines respectively with gas and liquid
flare valves of the outdoor unit.
• Repeat steps (A), (B), (C) when connecting
refrigerant piping lines to the flare valve of the
outdoor unit.
(1)
Fingers tighten
several turns the
flare nuts tightly of
first to obtain a
smooth match
Indoor Unit
Lubricate
Indoor unit tubing
Refrigerant
Piping Lines
Tightening Torque
Flare Nut
inch Mm
1/4" 6.35
1/2" 12.7
5/8" 15.88
(2)
Tighten flare nuts
with adjustable
wrench or torque
wrench.
32
Piping Line
Flare Nut
Indoor Unit
Piping
Refrigerant
Piping Lines
Flare Spanner or
Torque Wrench
Indoor
Side
Tightening Torque
N.M Kgf - cm
15-20 150-200
50-55 500-550
70-76 700-760