Refrigerant Piping - Mitsubishi Heavy Industries SRK25GZ-L1 Handbook

7.5.4 Refrigerant piping

(1) Preparation
Keep the openings of the pipes covered with tapes etc. to prevent dust, sand, etc. from entering them.
Indoor unit side
(Do not
turn)
Remove
¡ Remove the flared nuts.
(on both liquid and gas sides)
(2) Connection of refrigerant piping
Indoor unit side
¡ Connect firmly gas and liquid side
pipings by Torque wrench.
Spanner
(for fixing
the piping)
Torque
wrench
¡ Specified torquing value:
Liquid side (ø6.35) : 15.7~19.6 N·m (1.6~2.0kgf·m)
Gas side (ø9.52) : 29.4~39.2 N·m (3.0~4.0kgf·m)
¡ Always use a Torque wrench and back up spanner to tighten the flare nut.
(4) Air purge
(a) Tighten all flare nuts in the pipings both indoor and outside wall so as not to cause leak.
(b) Connect operating valve, charge hose, manifold valve and vacuum pump as is illustrated below.
(c) Open manifold valve handle Lo to its full width, and perform vaccum or evacuation.
Continue the vacuum or evacuation operation for 15 minutes or more and check to see that the vacuum gauge reads 0.1 MPa
(– 76 cm Hg).
(d) After completing vacuum operation, fully open service valve (Both gas and liquid sides) with hexagon headed wrench.
(e) Check for possible leakage of gas in the connection parts of both indoor and outdoor.
Stop valve
(Two-way valve)
Outdoor unit side
Press
Remove
¡ Remove the flared nuts.
(on both liquid and gas sides)
–76 cm Hg
Handle Lo
(pressure)
Stop valve
(Three-way
valve)
Charge hose
Service port
Press
¡ Install the removed flared nuts to the pipes to be connected,
then flare the pipes.
Outdoor unit side
¡ Connect firmly gas and liquid side
pipings by Torque wrench.
¡ Specified torquing value:
Liquid side (ø6.35) : 15.7~19.6 N·m (1.6~2.0kgf·m)
Gas side (ø9.52) : 29.4~39.2 N·m (3.0~4.0kgf·m)
¡ Use one more spanner to fix the valve.
Compound Pressure
Manifold
(Gauge) gauge
valve
Handle Hi
(pressure)
Charge hose
Vacuum pump
SCM-C
Dimension A
Liquid side
(φ6.35): 9-9.5 dia
Gas side
(φ9.52): 13.2-14 dia
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