53
7. HOW TO PROCESS TUBING
The narrow tubing side is connected by a flare nut,
and the wide tubing side is connected by brazing.
7-1. Connecting the Refrigerant Tubing
Use of the Flaring Method
Many of 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.
Flaring Procedure with a Flare Tool
(1) Cut the copper tube to the required length with a
tube cutter. It is recommended to cut approx. 30
– 50 cm longer than the tubing length you esti-
mate.
(2) Remove burrs at each end of the copper tubing
with a tube reamer or file. This process is impor-
tant and should be done carefully to make a good
flare. Be sure to keep any contaminants (moisture,
dirt, metal filings, etc.) from entering the tubing.
(Figs. 7-1 and 7-2)
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 be sure to
mount it on the copper tube.
(4) Make a flare at the end of the 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
NOTE
NOTE
Deburring
Before
After
Fig. 7-1
Reamer
Copper
tubing
Fig. 7-2
Flare tool
Flare nut
Copper
tubing
Fig. 7-3
A
φ
6.35
φ
9.52
φ
12.7
φ
15.88
9.1
13.2
16.6
19.7
A
0
– 0.4
Copper tubing
(Outer dia.)
Flare size: A (mm)
04-393 DC INV Tech p 45-63 12/13/04 11:34 AM Page 53
