HYDRAULIC OIL Master Copy for IRTMTCALD by IRICEN
HYDRAULIC OIL Master Copy for IRTMTC/ALD by IRICEN
HYDRAULIC OIL FUNCTION : To transmit power from one point to another • • • To lubricate moving parts. To cool or dissipate heat. To seal clearance between parts. Cushioning of oscillations caused by pressure jerks. Corrosion protection. Scuff removal.
HYDRAULIC OIL PROPERTIES • Suitable Viscosity: Viscosity is measure of fluid’s resistance to flow. If a fluid flows easily, its viscosity is low. Fluid flows with difficulty have a high viscosity. • Water Content: The water content has to be as low as possible. The maximum admissible concentration of water in the hydraulic oil is 1000 ppm. It means an oil quantity of 1000 litres contains 1 litre of water. • Viscosity Index: - The change in fluid viscosity caused by a change in temperature is referred to as the fluid’s viscosity index.
HYDRAULIC OIL PROPERTIES • Low pour point: - Pour point is the lowest temperature at which a fluid will flow. Beyond this it becomes so thick that it won’t flow any more. The pour point for hyd. Oil is kept -210 C. • High flash point: - Flash point is the temperature at which a liquid gives off vapour in sufficient quantity to ignite momentarily or flash when a flame is applied. Flash point of petroleum base hydraulic oil is 2100 C.
HYDRAULIC OIL PROPERTIES De-mulisification If a fluid (with or without the aid of chemicals) resists the formation of water-fluid emulsions and promotes the breakdown of emulsions, it is said to have ‘de-mulsification. ’
HYDRAULIC OIL PARAMETERS • Viscosity: The admissible decrease in viscosity is minus 10% of the original value. For eg VG 68 – 10% (6. 8) = 61. 2 cst at 400 c. • Water content: The water content has to be as low as possible. The maximum admissible concentration of water in the hydraulic oil is 1000 ppm. This corresponds to 0. 10% by volume. It means an oil quantity of 1000 litres contains 1 litre of water.
HYDRAULIC OIL PARAMETERS • Purity of oil: In order to ensure reliable operation maintain a degree of purity according to NAS 1638: 7 -8, ISO 4406: 19/16/13 - 20/17/14. • Acid content: The TAN (Total Acid Number) of fresh oil amounts to 0. 05 mg KOH/g. The values of used oil should be between 0. 05 and 1 mg/KOH/g.
HYDRAULIC USED IN TRACK MACHINE Keeping view for above quality of hydraulic oil, it is found that ISO VG 68 is the most suitable oil for power transmission in Plasser’s machines in Indian conditions. Hence oil ISO VG 68 is recommended for using transmission system in track machines. • Indian oil corporation - Servo system HLP-68 (N) • Bharat Petroleum Co. Ltd. - Bharat Hydol HDP-68 -SC • Balmer lawrie & Co. Ltd - Protomac HLP-68 • Hindustan Petroleum Co. Ltd. - Enklo HLP 68
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