Mitsubishi Electric HP120TNU-A Service Handbook page 318

[8-13 Parts Replacement Instructions ]
(14) Remove the braze from the pipe where circled in the figure, and unscrew the two screws on the check valve block fixing
plate to remove the check valve block assembly. (2 areas to remove braze from. 2 screws to be removed. See Figure 14.)
Check valve
Figure 14 Remove the
braze here.
Check valve block assembly
(15) Remove the braze from the pipe that connects to the gas-liquid separator (where circled in the figure), remove the two
screws on the check valve block fixing plate, and replace the check valve block assembly with a new one. (1 area to
remove braze from. 2 screws to be removed. 1 area to be brazed. See Figure 15.)
Remove the braze
here.
(Replacement parts)
Area to be brazed
Gas-liquid
separator
Figure 15
(16) Re-place the four-way valves (21S4a and 21S4b) that were removed in step (13). Figure 16-1 shows how to position a
new four-way valves.
Replace the center pipe below four-way valves (21S4a and 21S4b). (3 areas to remove braze from. 2 areas to be brazed.
See Figure 16-2.)
Four-way valve
(21S4a)
When seen from above, four-way
valves 21S4a and 21S4b are tilted
15°
by 15°.
Figure 16-1
HWE18220_GB
Check
valve block
Screws
to be
removed
Screws to
be removed
Remove the
braze here.
Rear view
Screws to be
removed
Check valve block assembly
Four-way valve (21S4b)
(53°)
(Replacement parts)
Four-way valve
(21S4a)
LEV2d
Area to be
brazed
Four-way valve 21S4a and
21S4b assemblies
Figure 16-2
Position the pipe perpendicular
to the horizontal plane of the
sheet metal (when seen from
above), and braze it on.
Four-way valve (21S4b)
Remove the pipe
that was cut in
step (13).
Replace the pipe that was cut
in step (13) with the pipe
included with the check valve
block assembly.
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chapter 8 -