Caution For Piping Connection/Valve Operation - Mitsubishi Electric CITY MULTI PUHY-P-YMF-B Installation Manual

10.3. Caution for piping connection/valve
operation
• Conduct piping connection and valve operation accurately by follow-
ing the figure below.
• The gas side connecting pipe is being assembled for shipment.
(See the figure at the right.)
1 For brazing to the connecting pipe with flange, remove the con-
necting pipe with flange from the ball valve, and braze it at the
outside of the unit.
2 During the time when removing the connecting pipe with flange,
remove the seal attached on the back side of this sheet and paste
it onto the flange surface of the ball valve to prevent the entry of
dust into the valve.
3 The refrigerant circuit is closed with a round, close-packed pack-
ing at the shipment to prevent gas leak between flanges. As no
operation can be done under this state, be sure replace the pack-
ing with the hollow packing attached at the piping connection.
4 At the mounting of the hollow packing, wipe off dust attached on
the flange sheet surface and the packing. Coat refrigerating ma-
chine oil onto both surfaces of the packing.
F
G
H
•
•
•
[Ball valve (liquid side)]
E
I
K
(This figure shows the valve in the fully open state.)
1
A Replace the close-packed packing
B Hollow packing
After evacuation and refrigerant charge, ensure that the handle is
fully open. If operating with the valve closed, abnormal pressure will
be imparted to the high- or low-pressure side of the refrigerant cir-
cuit, giving damage to the compressor, four-way valve, etc.
Determine the amount of additional refrigerant charge by using the
formula, and charge refrigerant additionally through the service port
after completing piping connection work.
After completing work, tighten the service port and cap securely not
to generate gas leak.
[Ball valve (gas side)]
E
J
A
3
B
A
B
C
D
15