21
A. Refrigerant pipe connection
• To ensure the efficiency, the pipe should be as short
as possible.
• Daub the refrigerant oil on the connector and the
flared nut.
• When bending the pipe, the bending semi-diameter
should be as large as possible against the pipe being
broken or bent.
• When connecting the pipe, aim at the center to
thread the nut by hand and tighten it with the double
spanners.
• Fastening torque please refers to "pipe specs and
fastening torque" on page 30.
• Don't let the impurity such as sand, water goes into
the pipe. Antifouling measures refer to Page 30.
Cautions in piping installation:
1.
When welding the pipe with hard solder, charge nitrogen into the pipe against oxidation.
The pressure gauge should be set at 0.02MPa. Perform the procedure with good nitrogen
circulation. Otherwise, the oxide film in the pipe may clog the capillary and expansion valve
resulting in accident.
2.
The refrigerant pipe should be clean. If the water and the other impurity enter the pipe, charge
the nitrogen to clean the pipe. The nitrogen should flow under the pressure of about 0.5MPa
and when charging the nitrogen, stop up the end of the pipe by hand to enhance the pressure
in the pipe, then loose the hand (Meanwhile stop up the other end).
3.
The piping installation should be executed after the check valves are closed.
4.
When welding the valve and the pipe, cool down the valve with wet towel.
5.
When the connection pipe and the branch pipe need to be cut down, please use the special
shears and do not use the saw.
6. When welding copper pipe, use the phosphor copper welding rod without any welding flux.
(Welding flux will damage the piping system. The welding flux containing chlorine will corrode
pipe. Especially, the welding flux with fluorine will damage refrigeration oil.)
1. Please select the refrigerant pipe according to the below material.
Material: the phosphoric oxidize seamless copper pipe, model: C1220T-1/2H (diameter is over
19.05); C1220T-O (diameter is below 15.88).
2. Thickness and specifications: The unit is charged with R-410A.
O-type should not be used for the pipe which diameter is over 19.05, or poor pressure
resistance will happen. Therefore, 1/2H type with its thickness over min. regulation should be
chosen.
3. The manifold pipe and branch pipe must be from AIRWELL.
4. When installing the check valve, refer to the relative operation instruction.
5. The pipe installation should be in the allowable range.
6. The installation of manifold pipe and branch pipe should be performed according to the
relative manual.
When fastening and loosing the
nut, operate with double spanners,
because only one spanner cannot
execute firmly.
If threading the nut without aiming
at the center, the screw thread will
be damaged, further it will cause
leakage.
Installation procedure
Pipe connection method
Pipe material and specs selection
Spanner
Connector
Nut
Spanner
