Lubricants should be considered working components in mechanical systems. As one would not install a dirty or damaged bearing, gears or valves on a piece of equipment using the wrong tools, "damaged" lubricants should not be added to the machine. Thus maintenance of your lubricants, and ultimately your equipment, begins with proper in-plant storage and handling.
Store lubricants in a cool, clean, and dry indoor area. Petroleum-based lubricants absorb airborne moisture if exposed to humid air, which begins to degrade the additive package and accelerates oxidation of the lubricant's base stock once it is put into service. Also, water might condense within the drum, drop to the bottom and get pumped to the machine during a top-off.
Storage temperatures should remain moderate at all times. Extreme hot or cold can cause chemical degradation. For example a rust inhibitor may have poor solubility in base oils leading to precipitation during storage. This precipitation is greatly accelerated during extreme cold conditions in winter. Further temperature fluctuations will cause movement of air between the atmosphere and the headspace of the container. For partially full containers, with greater headspace, this air movement is increased. The container inhales air when the temperature drops and exhales as the temperature rises even though the drum is sealed and does not leak lubricant through the bung.
Along with the air, moisture and small airborne particles enter the oil container possibly leading to degradation of the base stock and additives.
Bungs must be kept tight at all times and drum covers should be used whenever drums are stored in the upright position (bungs at 3 and 9 o'clock positions). Ideally, lubricants are stored in the horizontal position on proper storage racks allowing the containers to be rotated and used on a first-in, first-out basis.
Avoid outdoor storage of water-based fluids where extreme temperatures can have an even more damaging effect through freezing and evaporation.
If lubricants are stored outside, protect them from sun, rain, dust and other elements. Lay drums on their sides with the bungs in a horizontal (3 and 9 o'clock) position below the lubricant level. This will reduce the risk of the seals drying out and the ingestion of moisture caused by breathing.
Before dispensing stored lubricants where oil remains static for long periods of time, agitate them to re-suspend additives that may have fallen out during storage to ensure consistency in additive concentration i.e., to keep the additives evenly distributed.
Lubricant dispensing equipment often lies at the root of cross contamination problems. By dispensing oil through equipment that was previously used with a different lubricant, the two fluids mix, potentially causing lubrication impairment. Equipment such as hand pumps should be labeled to match the lubricant to be used with. Avoid the use of galvanized containers since the additive in the lubricant may react with the zinc plating, forming metal soaps that clog small openings and orifices in industrial machinery.
Grease containers should be stored right side up due to bleeding (fluid separation). Bleeding commonly occurs with grease and is more prominent at higher temperatures.
- Wipe off the tops and edges of containers before opening to avoid any contamination from improper handling.
These simple steps can substantially impact the useful life of your lubricants and your equipment.