Viscosity
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- Quality of how thick the oil is:
- Higher number = thick the oil is
- Viscosity decreases as refrigerant mixes with the oil
- Viscosity decrease with a increase in temperature
- A refrigerant oil must maintain a high enough viscosity to properly function at the highest normal operating temperature in the system
At the same time:
- The oil must remain liquid enough flow back to the compressor through the lowest temperature area of system
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Recommended Viscosity Ranges |
| Refrigerant |
| Ammonia |
(r-717) screw |
280-300 |
| Ammonia |
(r-717) reciprocating |
150-300 |
| Carbon Dioxide |
(r-744) reciprocating |
280-300 |
|
(r-11) centrifugal |
280-300 |
| |
(r-12) reciprocating |
150-300 |
| |
(r-12) centrifugal |
280-300 |
| |
(r-12) rotary |
280-300 |
|
(r-120 reciprocating |
150-300 |
| Other Halogenated |
reciprocating |
150-300 |
| Refrigerant |
cent. |
280-300 |
| All Halogenated Refrigerant |
screw |
150-300 |
- use POE with HFC
- use mineral with HCFC and CFC
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HFC…POE
- to store POE in metal containers because it will draw moisture thru the plastic
HCFC…Use Alkyl Benzene AB
- Alkyl Benzene can mix with mineral oil
HFC
HCFC…
- Have problems with miscibility with mineral oils (the oil will not return)
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