Leakage Detection And Heat Insulation Of Refrigerant Pipe - Trane MWD507 Installation & Operation Manual

Installation of refrigerant pipe
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Leakage detection and heat insulation of refrigerant pipe

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For more requirements of lines, please refer to the Installation, Operation and Maintenance Manual of
outdoor unit.
16
Purging:
a. Sustain the liquid pipe of the indoor unit with the insulating material in the hand.
b. When it is incapable to resist due to change of pressure, remove the insulating material
quickly, and make the nitrogen blow off fast from the pipe mouth (fi rst purging).
c. Then resist the pipe mouth with the insulating material (second purging).
d. Place a piece of clean cloth in front of the mouth, the nitrogen is ejected onto the cloth, and
dirt contained in the high-speed nitrogen is found. If the cloth becomes wet, it indicates that
water exists in the pipe. Repeat purging till no dirt is blown off and the cloth does not be
wet.
For indoor unit B, repeat the above mentioned operation.
After fi nishing working on the liquid pipe, carry out the aforesaid purging for the gas pipes.
After construction of the fi tting pipe fi nishes, a tightness test should be applied to the whole
refrigerating system (indoor unit and pipe). Fill the nitrogen to a specifi c pressure (R410A model
2
– 38 Kgf/cm ) simultaneously from both sides of the gas and liquid pipes, view whether there is
change of pressure, check whether each interface (welding or fl ared) and the whole system have
good tightness, and see if there have leakage sources.
Caution: when the air temperature at the time of pressurization is different from that at the time
of observation, correction should be carried out according to the following equation:
Actual value = Pressure at the time of pressurization + (Temperature at the time of pressurization
– Temperature at the time of observation) 0.1 Kgf/cm
If no gas leakage is detected, insulate the fi tting pipe with heat insulating material. The gas pipe
and liquid pipe need insulating respectively.
Incorrect
● The gas pipe and
liquid pipe should
not be insulated
together
Gas pipe
Liquid pipe
Control
cable
Heat
Surface
insulation
wrapping
tap
● Coupling portion
of the fitting pipe
should be
insulated
completely
No heat
insulation
for the joint
Correct
● Only the gas pipe ● Both the gas pipe
is insulated and liquid pipe are
(cooling only) insulated
Heat insulation
Gas pipe
Liquid pipe
Control
Gas
cable
pipe
Surface
Heat
Surface
wrapping tap
insulation
wrapping tap
2
● Insulated support
Heat
insulation
Liquid
pipe
Control
cable
Copper tube
Heat
insulation
Metal
support
Arc gasket
AMS-SVX04A-EN