How To Process Tubing; Connecting The Refrigerant Tubing - Panasonic R410A 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. (30 -
50 cm) 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 the 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
Caution Before Connecting Tubes Tightly
(1) Apply a sealing cap or water-proof tape to prevent dust or
water from entering the tubes before they are used.
(2) Be sure to apply refrigerant lubricant to the matching
surfaces of the flare and union before connecting them
together. This is effective for reducing gas leaks. (Fig. 5-4)
(3) For proper connection, align the union tube and flare tube
straight with each other, then screw in the flare nut lightly at
first to obtain a smooth match. (Fig. 5-5)
● Adjust the shape of the liquid tube using a tube bender at the
installation site and connect it to the liquid tubing side valve
using a flare.
Before
14
Deburring
After
Copper
tubing
Reamer
Flare nut
Flare tool
Apply refrigerant
lubricant.
Flare nut
Union
Fig. 5-1
Fig. 5-2
Copper
tubing
Fig. 5-3
Fig. 5-4
Fig. 5-5