Refrigerant Piping Work - Daikin FHQ35BVV1B Installation Manual

6. REFRIGERANT PIPING WORK

〈For refrigerant piping of outdoor units, see the installation manual attached to the outdoor unit.〉
〈Execute heat insulation work completely on both sides of the gas piping and the liquid piping.
Otherwise, a water leakage can result sometimes.〉
(When using a heat pump, the temperature of the gas piping can reach up to approximately 120°C, so use
insulation which is sufficiently resistant.)
〈Also, in cases where the temperature and humidity of the refrigerant piping sections might exceed
30°C or RH80 %, reinforce the refrigerant insulation. (20 mm or thicker) Condensation may form on the
surface of the insulating material.〉
〈Before refrigerant piping work, check which type of refrigerant is used. Proper operation is not pos-
sible if the types of refrigerant are not the same.〉
CAUTION
• Use a pipe cutter and flare suitable for the type of refrigerant.
• Apply ester oil or ether oil around the flare section before connecting.
• To prevent dust, moisuture or other foreign matter from infiltrating the tube, either pinch the end
or cover it with tape.
• Do not allow anything other than the designated refrigerant to get mixed into the refrigerant
circuit, such as air, etc. If any refrigerant gas leaks while working on the unit, ventilate the room
thoroughly right away.
• The outdoor unit is charged with refrigerant.
• Use copper alloy seamless pipes (ISO 1337).
• Be sure to use both a spanner and torque wrench together, as
shown in the drawing, when connecting or disconnecting pipes
to/from the unit. (Refer to Fig. 10)
• Refer to "Table 2" for the dimensions of flare nut spaces.
• When connecting the flare nut, apply ester oil or ether oil to the
inside of the flare section, and spin 3-4 times before screwing
in. (Refer to Fig. 11)
NOTE
• Use the flare nut included with the unit main body.
CAUTION
Do not let oil get on the screw holders on the dressing board.
Oil can weaken the screw holders.
Table 2
Pipe size Tightening torque
φ6.4(1/4")
14.2-17.2 N • m
φ9.5(3/8")
32.7-39.9 N • m
φ12.7(1/2")
49.5-60.3 N • m
φ15.9(5/8")
61.8-75.4 N • m
• Refer to "Table 2" to determine the proper tightening torque.
CAUTION
Overtightening may damage the flare and cause a refrigerant leakage.
English
Type of refrigerant
Applicable model
Fig. 10
Torque wrench
Flare nut
Fig. 11
Coat here with ester or ether oil.
Flare dimensions A (mm)
R410A
FHQ
8.7 – 9.1
12.8 – 13.2
16.2 – 16.6
19.3 – 19.7
Piping union
Spanner
Flare
R0.4-0.8
9