Extreme temperatures can make operating equipment more challenging. One reason for this is the way temperature affects lubricants. Industrial lubrication grease consists of a base oil and a metallic soap (or other thickener). Selecting the proper grease for your equipment is ultimately up to you and the manufacturer of your equipment. While Graco does not make specific grease recommendations, here are some things to consider when making your selection.
In colder climates it is important to select a grease that will not freeze at the lowest temperature to which it will be exposed. It is possible that the grease temperature will never be as low as the outside temperature because of the heat generated by the equipment; however, as a best practice use a grease that will not freeze at that lower temperature, just in case the equipment would ever be stored outdoors when it is not in operation.
For colder temperatures, the NLGI recommends using a softer grease (https://www.nlgi.org/faqs/). Softer grease contains less thickener and therefore more oil. Using an automatic lubrication system will allow you to use a softer grease because the grease is replenished on a regular basis and therefore less thickener is required. Be aware that even softer greases can still freeze if they get cold enough to freeze their base oil. For this reason it is important to inform your grease supplier of the lowest temperature of the working environment so they can help you select a grease that will not freeze.
In warmer climates, attention must be given to how a grease performs at higher temperatures. One problem is that heat will make the grease more fluid and more likely to seep out of a bearing, requiring more frequent application of grease. Graco’s automatic lubrication systems are the ideal solution to this problem. A second concern is that heat can accelerate oxidation in the grease, causing the metallic soap to harden and separate from the base oil (Machinery’s Handbook 28, page 2,345). Address both of these factors with the grease supplier. They can help you choose a grease that meets the needs of your equipment and the temperatures where the equipment is used.
At the end of the day, Graco is neutral on grease specification because our pumps are designed to work with a wide variety of greases. Consult with your equipment OEM and your grease supplier to select the grease that meets your needs. Let them know you intend to use a Graco automatic lubrication system, as that will offer them more flexibility in making the right choice for your application.
Article sourced from: Graco
JACK KOENIG, INDUSTRIAL LUBRICATION FIELD APPLICATION ENGINEER