Determine oxidation stability of steam turbine oils by rotating pressure vessel
1. Scope
1.1 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.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.2.1 Exception - Other units are provided in parentheses (psi, grams, and inches), because they are either the industry accepted standard or the apparatus is built according the figures in this standard, or both.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see 6.2, 6.4, 6.5, 6.6, and 6.10.
2. Referenced Documents
2.1 ASTM Standards
B 1 Specification for Hard-Drawn Copper Wire
D 943 Test Method for Oxidation Characteristics of Inhibited Mineral Oils
D 1193 Specification for Reagent Water
D 4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D 4742 Test Method for Oxidation Stability of Gasoline Automotive Engine Oils by Thin-Film Oxygen Uptake (TFOUT)
D 6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance
2.2 Energy Institute Standard
IP 229 Determination of the relative oxidation stability by rotating bomb of mineral turbine oil
3. Summary of Test Method
3.1 The test oil, water, and copper catalyst coil, contained in a covered glass container, are placed in a vessel equipped with a pressure gauge. The vessel is charged with oxygen to a gauge pressure of 620 kPa (90 psi, 6.2 bar) (see Eq 1), placed in a constant-temperature oil bath set at 150°C or dry block taken to 150°C (Fig. 1 and Fig. 2), and rotated axially at 100 rpm at an angle of 30° from the horizontal.
3.2 The number of minutes required to reach a specific drop in gauge pressure is the oxidation stability of the test sample.
100 kPa = 1.00 bar = 14.5 psi
4. Significance and Use
4.1 The estimate of oxidation stability is useful in controlling the continuity of this property for batch acceptance of production lots having the same operation. It is not intended that this test method be a substitute for Test Method D 943 or be used to compare the service lives of new oils of different compositions.
4.2 This test method is also used to assess the remaining oxidation test life of in-service oils.
