All cylinder parts, with the exception of a few items, are lubricated by the hydraulic oil in the circuit. Particular attention must be paid to keep the oil in the circuit clean. Whenever there is a hydraulic component failure (cylinder, pump, valve), and there is a reason to feel that metal particles may be in the system, the oil must be drained, the entire system fl ushed clean, and any fi lter screens thoroughly cleaned or replaced. New oil should be supplied for the entire system.Oil suitable and recommended for use in circuits involving Commercial cylinders should meet the following specifi cations:
Optimum operating viscosity is considered to be about 100 SSU。
* 50 SSU minimum @ operating temperature
7500 SSU maximum @ starting temperature
* 150 to 225 SSU @ 100o F. (37.8o C.) (generally)
44 to 48 SSU @ 210oF. (98.9oC.) (generally)
Viscosity Index: 90 minimum
Aniline point: 175 minimum
Rust and Oxidation (R & O) Inhibitors
Foam Depressant
Stability of physical and chemical characteristics.
High demulsibility (low emulsibility) for separation of water, air and contaminants.
Resistant to the formation of gums, sludges, acids, tars and varnishes.
High lubricity and fi lm strength.
| Oil Grade | 100OF.(37.8OC.) | 210O F.(98.9OC.) | |||
| SAE10 | 150 | 43 | |||
| SAE20 | 330 | 51 | |||
Normal Temperatures:
0oF. (-18oC.) to 100oF. (37.8oC.) ambient
100oF. (37.8oC.) to 180oF. (82.2oC.) system
Be sure the oil you use is recommended for
the temperature you expect to encounter.
A good quality hydraulic oil conforming to the characteristics listed above is essential to the satisfactory performance and long life of any hydraulic system.
Oil should be changed on regular schedules in accordance with the manufactures recommendations and the system periodically fl ushed.
Oil operating temperature should not exceed 200oF. (93oC.) with a maximum of 180o
F. (82oC.) generally recom-mended. 120oF. to 140oF. (50oC. to 60o C.) is generally considered optimum. High temperatures result in rapid oil deterioration and may point out a need for an oil cooler or a larger reservoir. The nearer to optimum temperature, the longer the service life of the oil and the hydraulic components.
Reservoir size should be large enough to hold and cool all the fl uid a system will need, yet it should not be waste-fully large. Minimum required capacity can vary anywhere between 1 and 3 times pump output. The reservoir must be able to hold all of the fl uid displaced by retracted cylinders when the system is not operating, yet provide spacefor expansion and foaming.
Oil poured into the reservoir should pass through a 100 mesh screen. Pour only clean oil from clean containers into the reservoir.
Never use Crank Case Drainings, Kerosene, Fuel Oil, or any Non-Lubricating Fluid, such as Water.
