Panasonic WH-ADF0309J3E5CM Service Manual page 115

12.1.5 How to Process Tubing
Must ensure mechanical connections be accessible for maintenance purposes.
12.1.5.1 Connecting the Refrigerant Tubing
Use of the Flaring Method
Many of conventional split system air conditioners employ the flaring method to connect refrigerant tubes that 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
estimate.
(2) Remove burrs at each end of the copper tubing
with a tube reamer or a similar tool. This process
is important 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.
When reaming, hold the tube end downward and be
sure that no copper scraps fall into the tube.
(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.
When flared joints are reused, the flare part shall be re-fabricated.
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 (ether oil) to
the inside of the flare nut before making piping
connections. This is effective for reducing gas
leaks.
(3) For proper connection, align the union tube and
flare tube straight with each other, then screw on
the flare nut lightly at first to obtain a smooth
match.

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.
115
Deburring
Before After
Copper
tubing
Reamer
Flare nut
Copper
Flare tool
tubing
Apply refrigerant
lubricant.
Union Flare nut