S4359128
21
7. How to Process Tubing
The narrow tubing side is connected by flare nut, and
the wide tubing side is connected by brazing.
7-1. Use of the Flaring Method
Many of the conventional split system air conditioners
employ the flaring method to connect refrigerant tubes
which run between indoor and outdoor units. In this
method, the copper tubes are flared at each end and
connected with flare nuts.
7-2. Flaring Procedure with a Flare Tool
(1)
Cut the copper tube to the required length with a
tube cutter. It is recommended to cut about
12 – 20 in. longer than the estimated tubing length.
(2)
Remove burrs at the end of the copper tube with
a tube reamer or file. This process is important
and should be done carefully to make a good
flare. (Fig. 7-1)
When reaming, hold the tube end downward and be
sure that no copper scraps fall into the tube. (Fig. 7-2)
(3)
Remove the flare nut from the unit and mount it
on the copper tube.
(4)
Make a flare at the end of copper tube with a flare
tool.* (Fig. 7-3)
*Use “RIGID®” or equivalent.
A good flare should have the following characteristics:
●
inside surface is glossy and smooth.
●
edge is smooth.
●
tapered sides are of uniform length.
7-3. Precaution before Connecting Tubes Tightly
(1)
Apply a sealing cap or water-proof tape to pre-
vent dust or water from entering the tubes before
they are used.
(2)
Apply refrigerant lubricant to the matching sur-
faces of the flare and union before connecting
them together. This helps to reduce gas leaks.
(Fig. 7-4)
(3)
For proper connection, align the union tube and
flare tube with each other, then screw in the flare
nut lightly at first to obtain a smooth match.
(Fig. 7-5)
●
Adjust the shape of the narrow and wide tubes
using a tube bender at the installation site and
connect them to the each tubing side valve using
a flare nut.
Fig. 7-1
Before
After
0126_M_I
Deburring
Copper
tubing
Reamer
0127_M_I
Fig. 7-2
Fig. 7-3
Flare nut
Copper
tubing
Flare tool
0128_M_I
Fig. 7-5
Union
Flare nut
0130_M_I
Fig. 7-4
Apply refrigerant
lubricant here and here
0129_M_I
NOTE
NOTE
