Lubrication Checkup: Oil “Lumps” Blocking Injectors

Symptom

We have experienced lubricant-injector failures in a number of our conveyor lubricators. We’ve used the same brand of high-temperature chain oil for the past five years without issue, except for the last drum. In that drum, we discovered coagulated “lumps” floating in the oil. The oil supplier is blaming our storage practices. Meanwhile, we’re having great difficulty getting the lubricators to work, despite changing the oil for fresh product. Any suggestions?

Diagnosis

Regarding lubricant condition, oil has a shelf life determined by base-oil type, additive-package ingredients, and the finished product’s storage prior to use. Most lubricating-oil manufacturers claim an estimated shelf life of +/-5 years when their products are stored correctly indoors. Wide temperature swings, however, can result in wax and sediment creation (if the oil gets too cold), premature oxidation (if it gets too hot), and condensation-moisture contamination from hot/cold temperature cycling. Interestingly, high-temperature lubricants can be manufactured with volatile carrier agents that can flash off during storage (especially if open to air) and cause the remaining lube to “thicken” or coagulate.

Regarding your lubricators, injector-style conveyor designs require priming on the lubricator’s initial fill or when the lubricant level falls below the pick-up tube point. Badly contaminated or coagulated lubricants can make the injector difficult or impossible to prime.

Prescription

• Always check with your supplier about the shelf life of your lubricant(s) and develop a purchase-quantity and stock-rotation strategy based on first in/first out principles and current usage patterns. To promote freshness, buy small amounts on a frequent basis and always use an indelible marker to note the receipt date on lubricant containers when they are delivered.
• Never store new containers of lubricant outdoors without protection from the elements. If possible, strive to store all oils and greases in a dry, indoor location at a temperature range between 0 and 110 F.
• Ensure that all lubricant-container bungs, lids, and breathers are always in place.
• Use a suitable cleaning or flushing agent to remove old oil from your lubricators, pumps included.
• Finally, remove and replace injectors with new ones of the same size, then prime the lubricator with fresh oil, according to the manufacturer’s instructions.
• Proper storage will go a long way toward achieving specified lubricant performance.