Determine oxidation stability of steam turbine oils by rotating pressure vessel
8. Preparation of Apparatus
8.1 Catalyst Preparation - Before use, polish approximately 3 m of the copper wire with a silicon carbide abrasive cloth and wipe free from abrasives with a clean, dry cloth. Wind the wire into a coil having an outside diameter 44 to 48 mm and weight of 55.6 more or less 0.3 g and stretched to a height of 40 to 42 mm. Clean the coil thoroughly with isopropyl alcohol, air-dry, and insert inside the glass sample container by a turning motion, if necessary. A new coil is used for each sample. For extended storage, the prepared coil may be packaged in a dry, inert atmosphere. For overnight storage (less than 24 h), the coils may be stored in n-Heptane.
NOTE 1 - Commercially available and prepackaged coils prepared as described in 8.1 can also be used for the test.
8.2 Cleaning of Vessel - Wash the vessel body, cap, and inside of vessel stem with a suitable solvent (for example, petroleum spirit, heptane, or acetone.) Wash with hot detergent solution and rinse thoroughly with water. Rinse the inside of the stem with isopropyl alcohol and blow dry with clean compressed air. Keep the plastic valve out of the hot detergent to prevent its deterioration. Failure to remove oxidation residue can adversely affect test results.
8.3 Cleaning of Glass Container - Drain and rinse with a suitable solvent (for example, non-reagent petroleum spirit, heptane, or acetone). Soak or scrub in an aqueous detergent solution. Brush thoroughly and flush thoroughly with tap water. Rinse with isopropyl alcohol, followed by distilled water and air dry. If any insolubles remain, soak overnight in an acid-type cleaning solution and repeat the above procedure starting from the tap water flush. Do not use chipped or cracked glassware.
8.4 Cleaning of Polytetrafluoroethylene (PTFE) Disk - Remove any residual oil with a suitable solvent and clean by brushing with detergent solution. Rinse thoroughly with tap water, followed by distilled water rinse and air dry.
