The shelf life of a lubricant is often an overlooked aspect when designing a lubrication program. Some lubricants may be kept in storage for more than a year, and most operators fail to understand the repercussions of doing this. Lubricants deteriorate over time and issues in some lubricants can arise even after a few months. This is why it is important to consult your supplier and know the shelf life of your lubricants. If any of your lubricants have been stored longer than their shelf life, perform adequate analysis to ascertain that the lubricants quality has not been compromised.
Apart from the duration of storage, the environment of storage plays an equally critical role in determining your lubricant’s condition. Environmental Factors that directly impact your lubricants are – Whether the lubricants are stored indoors or outdoors, the lubricant’s storage container, agitation of the lubricant, temperature, temperature variance and humidity. Maximizing your Lubricant’s storage life potential requires maintaining a cool, clean and dry environment.
Suppliers estimate a lubricant’s shelf life based on several characteristics such as the type of base oil, types of additives and types of thickeners. For example, lithium-based greases have a shelf life of one year and Calcium complex based greases have six months. Placed in ideal conditions, lubricants with low concentration of additives may even be stored for more than five years. Oils that are soluble and fire-resistant typically have a shorter shelf life of about six months.
Subjecting lubricants to long-term storage beyond recommendations from the supplier has some noteworthy concerns. Oils undergo oxidation, sediment buildup and moisture absorption over time. Greases develop the risk of oil and grease separation. Hence, it is highly recommended to perform analysis before using these lubricants. If these issues enter the system they would pose a much bigger threat to your operations.
If your facility is vast and you have several lube rooms spread across the plant, several factors should be considered. Firstly, check whether proper handling and environment is maintained in all of the rooms. Check if large quantities of particular oil are stored in multiple areas of the plant. If you store large quantities of the same oil in different rooms, you may have an unnecessarily large stock of that lubricant without your awareness.
To avoid this issue, many plants keep one room as the main lube room and several other much small rooms or lockers as auxiliary storage areas. Lubricants are delivered to the main lube room before distributing them across the plant to various storage areas. This enables lubricants to be rotated, inventoried and isolated more effectively. This approach has been successfully used in the industry for large plants.
For reliably utilizing your lubricants before the end of their shelf life while fulfilling all your lubrication needs, you need to establish some protocols. Set a storage limit to the quantity of lubricants stored for each category and follow the FIFO (first-in-first-out) practice for ideal inventory control. As the number and quantity of lubricants onsite are reduced, tacking and verifying deliveries will be easier.
Larger facilities frequently use remote lockers. They typically contain just enough lubricants required in the plant for a week or a month, thus ensuring that lubricants applied to the equipment are fresh. If you need to have a large lubricant replacement, use a drum and transfer it into the equipment using a filter cart and drum wand with quick connects.
Note that advanced training and proper documentation is required for personnel who manage multiple lube rooms. Performing inspection and undertaking proper preventive maintenance in the lube storage units requires skills and qualifications.
In conclusion, store your lubricants in a well-maintained environment; know your lubricant's shelf life before subjecting it to long-term storage; establish FIFO method for ideal inventory control and have qualified, well-trained personnel maintain your lube rooms.