MAYEKAWA 8M - Refrigerant Oil Control Standard

2202G1JE-DA-M-N_2010.01.
5 Maintenance
Reciprocating Compressor M Series 5.4 Refrigerant Oil Control Standard
5-6
5.4 Refrigerant Oil Control Standard
The refrigerant oil, to which the control standard is applied, is classified as follows:
1. Mineral oil: Naphthene series, Synthetic oil: Alkyl benzene (AB), Polyalphaolefin (PAO)
2. Synthetic oil: polyalkylene glycol (PAG) (Applicable refrigerant is NH
3
.)
Each item and standard is as follows. The control standard may be changed without notice depending on the
performance.
Table 5-3 1. Mineral oil: Naphthene series, Synthetic oil: Alkyl benzene (AB), Polyalphaolefin (PAO)
Item Standard
Color phase ASTM color standard: 6.0 or less
Total acid value 0.3 mg·KOH/g or less
Kinetic viscosity Amount of change must be within ±15% of the new oil.
Water amount 100 ppm or less
Degree of contamination Degree of contamination measured by mass method (millipore value) is
15 mg/100 m or less.
Table 5-4 2. Synthetic oil: Polyalkylene Glycol (PAG) *3 (Applicable Refrigerant is NH
3
.)
Item Standard
Color phase ASTM color standard: 4.0 or less
Total acid value 0.1 mg·KOH/g or less
Kinetic viscosity Amount of change must be within ±15% of the new oil.
Water amount 2000 ppm or less *1
Degree of contamination Degree of contamination measured by mass method (millipore value) is
15 mg/100 m or less *2
*1 This is a reference value because moisture may be included during sampling due to its high absorbability. In the NH
3
refrigerant,
NH
3
may be detected as water. If the amount is over this value by repeating the sampling for several times, it should be taken as the
control standard is exceeded.
*2 It is assumed that the following types of the oil filter are used: Paper filter (Filtering grain size of approx. 10 µm) for fluorocarbon,
paper filter or metallic mesh filter (300 meshes) and bypass filter (Filtering grain size of approx. 3 µm) for NH
3
*3 For NH
3
+ PAG, the rust is easily caused inside the equipment due to water absorption. Because the cleaning effect of PAG is higher
than other conventional mineral oil, the rust in the equipment is easily carried into the compressor so that the degree of
contamination tends to increase at the beginning of the operation. Therefore, it is recommended to replace the oil with new one after
2000—3000 hours have passed since the operation start. To prevent water adsorption while charging the oil, it is desirable to avoid a
rainy day. Complete charging of the oil within 15 min after the pail can is open.