McQuay MWSC 010 Series Manual page 41

Piping Works & Flaring Technique
ó Do not use contaminated or damaged copper tubing. If any pipings, evaporator or condenser had been exposed
or had been opened for 15 seconds or more, then vacuum and purge with fi eld supplied refrigerant. Generally, do
not remove plastic, rubber plugs and brass nuts from the valves, fi ttings, tubing and coils until it is ready to connect
suction or liquid line into valves or fi ttings.
ó If any brazing work is required, ensure that the nitrogen gas is passed through coil and joints while the brazing
work is being done. This will eliminate soot formation on the inside walls of the copper tubing.
ó Cut the pipe stage by stage, advancing the blade of the pipe cutter slowly. Extra force and deep cut will cause
more distortion on the pipe and thus extra burr. See Figure K.
ó Remove burrs from cut edges of the pipes with remover as shown in fi gure L. This will avoid unevenness on the
fl are faces which will cause gas leak. Hold the end of the pipe downwards to prevent metal chips from entering
the pipe.
COPPER TUBE
FIGUREK
ó Insert the fl are nuts, mounted on the connection parts of both the indoor unit and outdoor unit, onto the copper
pipes.
ó The exact length of pipe protruding from the face of the fl are die is determined by the fl aring tool. See Figure M.
The table shows the use of an imperial die and rigid die.
ó Fix the pipe fi rmly on the fl are die. Match the centers of both the fl are die and the fl aring punch, and then tighten
the fl aring punch fully.
FIGUREL
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