Handling and storage of grease has a major impact on the life of the product.

Like most materials, lubricating grease gradually will deteriorate with time. The rate and degree of deterioration depends on the storage and handling and storage of the grease

Grease may change its characteristics during storage. The product may oxidize, bleed, change in appearance, pick up contaminants or become firmer or softer. The amount of change varies with the length of storage, temperature and nature of the product.

What effects do handling and storage of the grease have?

Depending on the storage conditions,
some greases can undergo age hardening, which results in the product becoming firmer and increasing in consistency or even softening.

These changes in consistency can cause the grease to slip out of its original consistency grade. This behaviour can be further aggravated by prolonged storage conditions. Because of this aspect, extended grease storage periods should be avoided.

Greases tend to bleed and release their base oils during storage. The rate of oil released from the grease will increase with time and vary based on the temperature at which it is stored.

If a grease has been in storage for more than a year, the National Lubricating Grease Institute (NLGI) recommends that it be inspected and the worked penetration tested to ensure that the grease is still within its intended NLGI grade.

Another recommended industry practice specifies that whenever any type of lubricant is received, the usage and storage methods must follow the first-in/first-out inventory system.

This simply requires the user of the lubricating grease to use the grease that was put into the storage system first. In addition, grease manufacturers place a date code or bath number on the individual packages or cartons that can help determine the month, day and year the grease was made.

What are the best practices WRT handling and storage of the grease?

Ideally, grease should be stored in a cool, dry indoor area that does not exceed 30 degrees C and remains above 0 degrees C.

It is not unusual to find grease containers in storage areas that have temperatures as high as 54 degrees C. These storage areas also can be exposed to contaminants such as dust, dirt, moisture or rainwater, which can severely deteriorate the quality of the grease.

A grease container should never be exposed to direct sunlight or be stored in an area directly near a heat source such as a steam pipe, furnace, in the cab of a truck in hot weather, etc. This will only aggravate the rate of oil release.

Always store grease in its original packaging and keep the container closed until it is time for it to be used. Wipe the lid or cover of the container before opening and always use clean tools and dispensing equipment when handling or pumping the grease.

After use, the container should be closed immediately and kept closed. Before placing the lid back onto the container, wipe off any dust, dirt or excess grease that may have accumulated.

Cartridge tubes of grease should be stored upright at all times. If a cartridge tube is left in a grease gun, the grease gun should be depressurized, wiped with a clean cloth to remove any contaminants and stored in a horizontal position inside a clean, cool, dry area to keep the oil from bleeding out of the grease.

Tips for storage and handling of grease:

• Do not use lubricating greases that have been stored for long periods of time unless their condition and cleanliness can be verified by a laboratory analysis. 
• If accidental mixing is suspected or has occurred during the storage and handling of grease, consult the lubricant supplier or conduct compatibility tests. 
• The grease storage room should be separated from areas of contamination such as metal debris, dust, dirt, chemical fumes or moisture. 
• Grease containers should be clearly labeled with the date they were received, the type and brand of grease, etc. These markings should be kept in a position where they can be easily read. 
• Never leave grease containers improperly covered, uncovered or open. Keep them tightly sealed between uses. If the containers are stored outside, a heavy canvas tarpaulin, plastic sheet or lean-to can be used to keep off water or dirt. Drums, kegs and pails should be raised off the ground and stored either on their sides or tilted at a 45-degree angle to prevent any moisture or dirt from being drawn into the product. 
• Any tools used for handling the grease should be cleaned before they are used. 

 

• If a barrel warmer is used to facilitate handling after storage of the grease, it should have some type of temperature-regulating mechanism. The grease should never be heated above 25 degrees C, and the barrel warmer should not be left on overnight or unattended. This can cause the grease to readily release its base oils or even thicken in consistency due to oxidation and thermal stress. 
• Maintain a separate inventory and utilization record for each product. Tracking how much grease is used and on which machine or piece of equipment will help you keep an accurate inventory of lubricants. 
• Use the oldest container received first. 
• Some type of coding and tagging system should be used to identify the handling and storage of the grease throughout the plant. Make sure all transfer valves, hoses and dispensing equipment are kept clean. Seals and gaskets also should be maintained in proper condition.

The handling and storage of the grease to ensure long life and effective lubricity is one part of the equation in effective plant lubrication; the other is obviously the quality of the grease that you use. For the best advice and quality synthetic grease give Habot Synthetic Lubricants a call.