How To Process Tubing; 5-1. Connecting The Refrigerant Tubing; Outdoor Units - Panasonic U-72MF1U9 Installation Instructions Manual

5. HOW TO PROCESS TUBING

The liquid tubing side is connected by a flare nut, and the gas
tubing side is connected by brazing.

5-1. 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. 1 – 2 ft. longer
than the tubing length you estimate.
(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. 5-1)
NOTE
When reaming, hold the tube end downward and be sure that
no copper scraps fall into the tube. (Fig. 5-2)
(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 copper tube with a flare tool.
(Fig. 5-3)
NOTE
A good flare should have the following characteristics:
● inside surface is glossy and smooth
● edge is smooth
● tapered sides are of uniform length
Deburring
Before
Fig. 5-1
Fig. 5-2
Flare tool
Fig. 5-3
32
After
Copper
tubing
Reamer
Flare nut
Copper
tubing