14 Piping installation
Installation and operation manual
23
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1D – 2020.10
To handle the service port
▪ Always use a charge hose equipped with a valve depressor pin,
since the service port is a Schrader type valve.
▪ After handling the service port, make sure to tighten the service
port cover securely. For the tightening torque, refer to the table
below.
▪ Check for refrigerant leaks after tightening the service port cover.
Tightening torques
Stop valve
size (mm)
Tightening torque N•m (turn clockwise to close)
Shaft
Valve body Hexagonal
wrench
Cap (valve
lid)
Service
port
Ø9.5
5.4~6.6
4 mm
13.5~16.5
11.5~13.9
Ø12.7
8.1~9.9
18.0~22.0
Ø15.9
13.5~16.5
6 mm
23.0~27.0
Ø19.1
27.0~33.0
8 mm
22.5~27.5
Ø25.4
14.3.7
To remove the spun pipes
NOTICE
In case of heat pump system, do NOT remove the spun
pipe of the suction gas stop valve.
WARNING
Any gas or oil remaining inside the stop valve may blow off
the spun piping.
If these instructions are NOT followed correctly it may
result in property damage or personal injury, which may be
serious depending on the circumstances.
Use the following procedure to remove the spun piping:
1
Make sure that the stop valves are fully closed.
2
Connect the vacuuming/recovery unit through a manifold to the
service port of all stop valves.
p< p>
R410A
N2
b
c
e
a
f
g
h
d
A
C
(1)
D
B
a
Pressure reducing valve
b
Nitrogen
c
Weighing scales
d
Refrigerant R410A tank (siphon system)
e
Vacuum pump
f
Liquid line stop valve
g
Gas line stop valve
h
High pressure/low pressure gas line stop valve
A
Valve A
B
Valve B
C
Valve C
(1)
D
Valve D
(1)
Only for heat recovery system.
NOTICE
Do not connect the vacuum pump to the suction gas stop
valve if the unit is intended to run as a heat pump system.
This will increase the risk of unit failure.
3
Recover gas and oil from the spun piping by using a recovery
unit.
CAUTION
Do not vent gases into the atmosphere.
4
When all gas and oil is recovered from the spun piping,
disconnect the charge hose and close the service ports.
5
Cut off the upper part of the following pipes with an appropriate
tool (e.g. a pipe cutter):
a
c
b
a
c
b
Heat pump system
Heat recovery system
a
High pressure/low pressure gas stop valve
b
Suction gas stop valve (ONLY use in case of heat recovery
system)
c
Liquid stop valve
WARNING
NEVER remove the spun piping by brazing.
Any gas or oil remaining inside the stop valve may blow off
the spun piping.
6
Make sure that no particles remain in the pipe. Blow out any
particles with compressed air.
7
Wait until all oil has dripped out before continuing with the
connection of the field piping in case the recovery was not
complete.
