GEA Grasso V Series, Инструкция по установке и обслуживанию

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4.6 LUBRICATING OILS (choice and recommendations)
Caution!
In case a Grasso compressor is used inside a GEA Grasso produced
chiller, the applicable oils could be limited compared with the oils
mentioned in this chapter for use with NH
3
as refrigerant. The oils to
be used will then be specified in the Chiller Product information.
Warning!
The choice of oil for a refrigeration compressor should be made by
taking into account the entire refrigeration system design and
operation as well as the operating conditions of the compressor.
For lubrication of refrigeration compressors, several brands and types of specially
developed lubricating oils are on the market. The choice of oil depends not only
on its good lubrication properties (viscosity) and chemical stability at the
operating conditions of the compressor, but also on the operating conditions of
the refrigerating plant (solidifying and floc point, solubility).
Grasso has tested and approved for use in its reciprocating-compressors the
brands and types of oil as listed tables below.
The choice of the lubricating oil depends on type of refrigerant and the operating
conditions of the compressor.
The oil viscosity should always be more than 10 cSt. Assumed is that the oil
temperature at the bearing surfaces = 15 K above crankcase oil temperature.
A higher ISO-VG number should be chosen when refrigerant solubility in
crankcase is expected.
Remarks
1. Using ISO VG100 oils to increase viscosity at high expected cranckcase-
temperatures makes no sense as the friction-heat will increase that much,
that the oil-temperature limit related to the minimum viscosity of 10 cSt will
also be exceeded. Only in case of expected high refrigerant-concentrations in
the cranckcase this viscosity-gradeoil is an alternative!
2. Using ISO VG46 oils to meet low pour point requirements is only acceptable if
coupled to a high viscosity-index of at least 100, otherwise the working limits
are so limited (again concerning the minimum required oil-viscosity of 10 cSt)
that it can be used in medium evaporation-pressures, making no sense to use
them al a low pourpoint alternative!
Hint!
Some of the oil types listed in the tables may be marketed under other
names and/or designations; these oils can also be used, provided
their identity can be proved beyond any doubt. Application of other/
alternavive oils is not permitted without the written consent of Grasso.
4.6.1 STRONGLY RECOMMENDED OIL TYPES
APPENDIX; Product Information (PI)
LUBRICATING OILS (choice and recommendations)
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58 30.10.2017