Advertisement
10
Plumbing materials and storage methods
Pipe must be able to obtain the specified thickness and should be
used with low impurities.
Also when handling storage, pipe must be careful to prevent a
fracture, deformity and wound.
Should not be mixed with contaminations such as dust, moisture.
Refrigerant piping on three principles
Drying
Should be no moisture
inside
Moisture
Items
- Significant
- Degradation of
hydrolysis of
refrigerant oil
refrigerant oil
- Poor insulation of
- Degradation of
the compressor
refrigerant oil
Cause
- Do not cold and
- Poor insula'tion of
warm
failure
the compressor
- Clogging of EEV,
- Do not cold and
Capillary
warm
- Clogging of EEV,
Capillary
- No moisture in the pipe
- No dust in the pipe.
- Until the
- Until the
connection is
connection is
completed, the
completed, the
plumbing pipe
plumbing pipe
entrance should be
entrance should be
strictly controlled.
strictly controlled.
- Stop plumbing at
- Pipe entrance
rainy day.
should be taken
side or bottom.
Counter
- Pipe entrance
should be taken
- When removal burr
measure
side or bottom.
after cutting pipe,
pipe entrance
- When removal burr
should be taken
after cutting pipe, pipe
down.
entrance should be
taken down.
- Pipe entrance
should be fitted cap
- Pipe entrance
when pass through
should be fitted cap
the walls.
when pass through
the walls.
Cleanliness
Airtight
There is no refrigerant
No dust inside.
leakage
Dust
Leakage
- Gas shortages
- Degradation of
refrigerant oil
- Poor insulation of
the compressor
- Do not cold and
warm
- Airtightness test
should be.
- Brazing operations
to comply with
standards.
- Flare to comply
with standards.
- Flange connections
to comply with
standards.
Nitrogen substitution method
Welding, as when heating without nitrogen substitution a large
amount of the oxide film is formed on the internal piping.
The oxide film is a caused by clogging EEV, Capillary, oil hole of
accumulator and suction hole of oil pump in compressor.
It prevents normal operation of the compressor.
In order to avoid this problem, Welding should be done after replacing
air by nitrogen gas.
When welding plumbing pipe, the work is required.
Welding Point
Oxide scale
Note) should not block the outlet side.
When the internal pressure in pipe is abo
ve the atmospheric pressure, pinhole is
occurred and it is a leakage cause.
CAUTION
!
• Always use the nitrogen.(not use oxygen, carbon dioxide, and a
Chevron gas): Please use the following nitrogen pressure 0.02 MPa
(2.9 psi) Oxygen - Promotes oxidative degradation of refrigerant oil.
Because it is flammable, it is strictly prohibited to use Carbon
dioxide - Degrade the drying characteristics of gas Chevron Gas -
Toxic gas occurs when exposed to direct flame.
• Always use a pressure reducing valve.
• Please do not use commercially available antioxidant.
The residual material seems to be the oxide scale is observed. In
fact, due to the organic acids generated by oxidation of the
alcohol contained in the anti-oxidants, ants nest corrosion occurs.
(causes of organic acid → alcohol + copper + water +
temperature)
Regulator
Nitrogen gas
Pressure 0.02 MPa
(2.9 psi) less
Auxiliary valve
Taping
(Should not
contain air)
Advertisement
