OXIDATION STABILITY OF STEAM TURBINE OILS BY ROTATING PRESSURE VESSEL: D2272
EXPLANATION
The estimate of oxidation stability is useful in controlling the continuity of this property for batch acceptance of production lots having the same operation. This test method utilizes an oxygen pressured vessel to evaluate the oxidation stability of new and in-service turbine oils having the same composition (base stock and additives) in the presence of water and a copper catalyst coil at 150° C. It is not intended that this test method be a substitute for Test Method D943 or be used to compare the service lives of new oils of different compositions. This test method is also used to assess the remaining oxidation test life of in-service oils. A modification of the rotating vessel method has been published as Test Method D2112, which uses a similar procedure and apparatus but a lower (140° C) bath temperature. That method requires duplicate testing; Test Method D2272 also conducted duplicate testing in the past.
TEST SUMMARY
The test oil, water, and copper catalyst coil, contained in a covered glass container, are placed in a vessel equipped with a pressure gage. The vessel is charged with oxygen to a gage pressure of 620 kPa, placed in a constant temperature oil bath set at 150° C, and rotated axially at 100 r/min at an angle of 30° from the horizontal. The number of minutes required to reach a specific drop in gage pressure is the oxidation stability of the test sample.
TEST PRECISION
Repeatability: 0.12 X
Reproducibility: 0.22 X
Where X is the mean value.
There being no criteria for measuring bias in these test-product combinations, no statement of bias can be made.
