44
Expansion Valve, Liquid Valve, Bypass Valve and
Waste Heat Recovery Valve Replacement Procedure
5. Install the expansion valve, liquid valve, bypass valve and waste heat recovery valve.
(1) Attach the replacement expansion valve, liquid valve, and bypass valve to the piping on the side of the unit.
Caution
When replacing the expansion valve, liquid valve, bypass valve and waste heat recovery valve, take care not to
apply shock to the valves.
(2) Weld the piping while cooling the expansion valve, liquid valve, bypass valve and waste heat recovery
valve units with a wet cloth (valve units: 120°C or less).
*When soldering, be sure to replace with nitrogen gas.
(3) Install the solenoid valve coils.
(4) Perform an air tightness test with nitrogen from the low pressure outlet, and make sure there are no
leaks from the welded parts.
Air tightness test pressure 2.3 [MPa]
(5) If the air tightness test is satisfactory, reinstall the pipe securing bracket, thermal insulation, and rubber.
(6) Purge the refrigeration circuit..
Degree of vacuum
0.133 [kPa/abs]
1.0 [mmHg]
Set to valve open and carry out evacuation from the low pressure outlet. After evacuation is
¿
nished, cancel the
valve open setting.
6. Preparation for operation
(1) Cancel pump-down.
Set each of the closing valves from the fully closed position to the fully open position. (Figures 2 & 3)
Outdoor unit
Refrigerant liquid
tube
Refrigerant gas
tube
Refrigerant intake
tube
Refrigerant
discharge tube
3 WAY MULTI
NA
Other than above
NA
NA
: Applicable
NA: Not applicable
Set the refrigerant gas and refrigerant liquid closing tubes and the balance tube from the fully closed position to
the fully open position.
The
¿
gure below illustrates valves
other than 3-way valves.
3 WAY MULTI Refrigerant liquid tube, refrigerant intake tube, and
refrigerant discharge tube (total of three closing valves)
Figure 2
Refrigerant
liquid tube
Refrigerant
gas tube
Open
Refrigerant
liquid tube
Refrigerant
gas tube
Closed
Note) For details on 3WAY multi valves, refer to “3. Basic
Operations for Shutoff Valves of 3WAY MULTI”
under “Basic Operations” in this manual.
Figure 3
Fully open
Closed valve
open/close
Status
Fully closed
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