Refrigerant Piping - Mitsubishi Heavy Industries SRK25GZ-L1 Handbook

SRK-H

2.5.4 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(1.6~2.0 kgf·m)
Gas side (ø12.7)
¡ Always use a Torque wrench and back up spanner to tighten the flare nut.
(3) 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 vacuum or evacuation.
Continue the vacuum or evacuation operation for 15 minutes or more and check to see that the vacuum gauge reads
– 0.1MPa (– 76cm Hg).
(d) After completing vacuum operation, fully open operating 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)
82
Outdoor unit side
Press
¡ Remove the flared nuts.
(on both liquid and gas sides)
: 39.2~49.0 N·m(4.0~5.0 kgf·m)
–76 cm Hg
Charge hose
Service port
Press
Remove
¡ 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(1.6~2.0 kgf·m)
Gas side (ø12.7) : 39.2~49.0 N·m(4.0~5.0 kgf·m)
¡ Use one more spanner to fix the valve.
Compound Pressure
Manifold
(Gauge) gauge
valve
Handle Lo
Handle Hi
(pressure)
(pressure)
Stop valve
(Three-way
Charge hose
valve)
Vacuum pump
Dimension A
Liquid side
(φ6.35): 9-9.5 dia
Gas side
(φ9.52): 13.2-14 dia
(φ12.7): 16.2-17 dia