– 34 –
1) Be sure to make setting so that
liquid
can be charged.
2) When using a cylinder equipped with a siphon, liquid can be charged without turning it upside down.
R32 refrigerant is a Single-component refrigerant that does not change its composition.
Although it is possible to charge the refrigerant with either liquid or gas, charge it with liquid.
(If using gas for charging, composition of the refrigerant changes and then characteristics of the air conditioner
change.)
6-5. Brazing of Pipes
6-5-1. Materials for Brazing
1. Silver brazing filler
Silver brazing filler is an alloy mainly composed
of silver and copper.
It is used to join iron, copper or copper alloy, and
is relatively expensive though it excels in solder
ability..
2. Phosphor bronze brazing filler
Phosphor bronze brazing filler is generally used
to join copper or copper alloy.
3. Low temperature brazing filler
Low temperature brazing filler is generally called
solder, and is an alloy of tin and lead.
Since it is weak in adhesive strength, do not use
it for refrigerant pipes.
1) Phosphor bronze brazing filler tends to react with
sulfur and produce a fragile compound water
solution, which may cause a gas leakage.
Therefore, use any other type of brazing filler at a
hot spring resort, etc., and coat the surface with a
paint.
2) When performing brazing again at time of
servicing, use the same type of brazing filler.
6-5-2. Flux
1. Reason why flux is necessary
• By removing the oxide film and any foreign
matter on the metal surface, it assists the flow of
brazing filler.
• In the brazing process, it prevents the metal
surface from being oxidized.
• By reducing the brazing filler’s surface tension,
the brazing filler adheres better to the treated
metal.
Gauge manifold
[ Cylinder with siphon ]
[ Cylinder without siphon ]
OUTDOOR unit
Gauge manifold
OUTDOOR unit
Refrigerant
cylinder
Electronic
balance
Refriger
ant
cylinder
Electronic
balance
Siphon
Fig. 6-4-2
