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REFRIGERANT PIPING WORK
3) After the work is finished, make sure to check that there is no
gas leak.
4) After checking for gas leaks, be sure to insulate the pipe connections.
• Insulate using the insulation for fitting included with the liquid and gas pipes. Besides, make sure the insulation for fitting
on the liquid and gas piping has its seams facing up.
(Tighten both edges with clamp.)
• For the gas piping, wrap the medium sealing pad over the insulation for fitting (flare nut part).
Caution
Be sure to insulate any field piping all the way to the piping connection inside the unit. Any exposed piping may cause
condensation or burns if touched.
Cautions on Pipe Handling
• Protect the open end of the pipe against dust and moisture.
(Tighten both edges with clamp.)
• All pipe bends should be as gentle as possible. Use a pipe bender for
bending.
(Bending radius should be 30 to 40 mm or larger.)
Selection of Copper and Heat Insulation materials
When using commercial copper pipes and fittings, observe the following:
• Insulation material: Polyethylene foam
Heat transfer rate: 0.041 to 0.052W/mK (0.035 to 0.045 kcal/mh°C)
Refrigerant gas pipe’s surface temperature reaches 110°C max.
Choose heat insulation materials that will withstand this temperature.
• Be sure to insulate both the gas and liquid piping and to provide insulation dimensions as below.
Also, when subject to high humidity, heat insulation of the refrigerant
piping (the unit piping and branch piping) must be further reinforced.
Reinforce the insulation when installing the unit near bathrooms,
kitchens, and other similar locations.
Refer to the following:
• 30°C, more than 75% RH: 20 mm Min. in thickness
If the insulation is not sufficient, condensation may form on the surface
of the insulation.
• Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
Coat here with
refrigeration machine oil
Torque wrench
Piping union
Flare nut
Spanner
Gas pipe
Liquid pipe
Piping insulation
material (main unit)
Attach to base
Flare nut connection
Turn seams up
Insulation for fitting
(attached)
Clamp
Piping insulation material
(Field supplied)
Gas Piping Insulation Procedure
(attached)
Main unit
Clamp (attached)
Flare nut connection
Turn seams up
Piping insulation material
(Field supplied)
Piping insulation
material (main unit)
Attach to base
Main unit
Insulation for fitting
(attached)
Liquid Piping Insulation Procedure
Small sealing pad
Measure the length of the gas
pipe as you will have to cover
it with the sealing tape.
(attached)
Wrap the sealing
tape around the
gas pipe.
Main unit
Wall
If no flare cap is
available, cover
the flare mouth
with tape to keep
dirt or water out.
Be sure to
place a cap.
Rain
Gas side
Gas pipe thermal insulation
Liquid side
Liquid pipe
thermal insulation
25/35 class
50/60 class
O.D. 9.5mm
O.D. 12.7mm
25/35 class
50/60 class
I.D. 12-15mm
I.D. 14-16mm
Thickness 0.8mm
O.D. 6.4mm
I.D. 8-10mm
Thickness 10mm Min.
Gas pipe
Liquid pipe
Gas pipe
insulation
Liquid pipe
insulation
Finishing tape
Drain hose
Inter-unit wiring
01_EN_3P132003-2N.fm Page 7 Tuesday, December 5, 2006 2:02 PM
