Hitachi RAS-18FSXNS2E - Piping Connection; Stop Valve

34
PMML0628 rev.0 - 05/2023
3
PIPE CONNECTION
PIPING WORK AND REFRIGERANT CHARGE
3.3.3 Piping connecon
Aer connecng the pipes, remove the caps of stop valves for gas and liquid.
Tighten the open-close spindle in the closing direcon according to the following ghtening
torque.
1 Make sure that the stop valves are closed.
2 Fill pipes with nitrogen gas before brazing.
3 Protect the compressor and sound-proof cover with a metal plate when brazing the gas pipe.
! CAUTION
Pay aenon to the ame of the burner does not burn the stop valve body.
4 Connect the indoor unit and outdoor units with refrigerant piping. Fix the pipes and take special
care no to contact with weak porons such as wall, ceiling, etc. Otherwise, abnormal sound may
be heard due to vibraon of the piping.
 NOTE
Where pipes are buried in situ with joints such as elbows or sockets, provide a service access door
to facilitate checking of the connecng part.
5 As for the aring work of the eld pipe, use the specied ghtening torque.
6 Insulate the gas pipe and liquid pipe completely.
7 Mount the pipe cover equipped with the outdoor unit aer connecng the pipes.
Otherwise, the unit may be damaged due to snow or rainwater entering the pipes.
Pipe size Ø (mm)
Tightening Torque (Nm)
6.35 14 to 18
9.52 34 to 42
12.7 49 to 61
15.88 68 to 82
19.05 100 to 120
3.3.4 Stop valve
Follow the restricons for refrigerant piping (permissible length, height dierence). If not, the
outdoor unit may be damaged or fail.
The stop valves shall be closed completely (factory seng) when the refrigerant piping connecon
is performed. Do not open the stop valves unl all the refrigerant piping connecons, air-ght test
and vacuuming have been completed.