Authored by: Allan Zieser, STLE, CLS
We’ve all seen it! You pour the oil into a frying pan, and it sits on the bottom looking like a drop that is not quite flat. The oil is there at room temperature and it has a thickness to the film that is on the pan. But then, we turn up the heat, preparing to cook with it, and that thicker film of oil suddenly thins out. Leave it on there long enough at higher temperatures and it will begin to turn brown and oxidize. Leave it even longer, and a burnt varnish film will form and adhere to the metal of the pan.
This is the same process that is involved with the lubricants in your equipment.
Take an oil with a viscosity of ISO 46, heat it up enough, and you will end up with an oil that has a viscosity of 32 or possibly lower at the higher operating temperature. Heat it up more, and that oil gets thinner. Heat it enough and it will oxidize and form that familiar film of varnish on your equipment. This process will continue until the unit the oil is in fails due to inadequate lubrication.
The opposite is true if the operating temperature is cold. Take that same ISO 46 oil, put it in a cold environment and the viscosity will rise as the temperature decreases. Our ISO 46 oil may rise in viscosity until it is an ISO 68, ISO 100, or even higher. Too cold, and the oil will not flow and will not protect the parts of your equipment. Cold weather can also increase the thickness of the oil enough that the equipment will not start at all.
So, how do we fix these issues? When we recommend an oil viscosity, we always need to take the operating temperature of the equipment into account. If the temperature is hot or cold enough, we will recommend a thicker or thinner fluid based on these temperatures. In the case of a hot temperature, we may move to and ISO 68 to compensate for the increase in temperature, allowing the oil to be at the ISO 46 that is needed during operation because the thicker oil is compensating for the increase in temperature. With the colder temperatures, we will move to a thinner oil, say an ISO 32 or ISO 22, to allow for the oil thickening that will happen due to colder temperatures.
Most equipment manuals will have an operating temperature chart that will show you which viscosity of oil to use at different operating temperatures. However, if your manual is missing you can turn to the experts at Ottsen Oil. We will work diligently with your personnel to choose the correct viscosity and the correct type of lubricant for your applications, allowing your equipment to operate at a greater value to you.