In many industries immersion heaters are utilized to ensure that lubricating oils remain fluid or at the right viscosity and prevent waxing. If an oil starts to thicken due to low temperatures, it defeats the purpose of lubrication, and you will start to see increased wear to your equipment.
Typically, you will see immersion heaters in a storage tank setting within a lube system. This is similar in concept to the style of heat/heater you would see in a fish tank. The heater is providing localized heat. If the system is not circulating or the fluid levels, go below the heater, damage can be done both to the heater and fluid.
Overheating Oil
Especially during the colder months, heaters could be set higher than normal to combat extreme conditions. This could lead to your oil overheating causing some serious condition issues. To monitor for potential overheating issues, be sure to test your storage tanks regularly and frequently, but especially through the winter when the weather can be a significant contributing factor to potential changes in fluid properties. A good practice is to also test your oil in the spring after you no longer require the heater, if you aren’t already testing it at regular intervals.
Typical signs that you oil has been overheated include:
- High oxidation levels: a general rule of thumb is anything over 60C, with every 10C increase you are going to double your rate of oxidation.
- Varnish formation: be sure to frequently check the storage tank and equipment for signs of varnish deposits forming.
- Unexpected viscosity changes (chemically alter the fluid): by overheating your fluid you are running the risk of permanently altering the chemical make-up of the fluid. If the temperature is too high, you can potentially thermally crack your oil.
Considerations to Reduce Overheating
A few things to keep in consideration to reduce the likelihood of altering your oil over the winter are:
- Don’t oversize your heater. You may think having a larger heater will reduce the need to have it on for longer periods of time, but your tank size and fluid type MATTER. Talk with your OEM and get them sized properly for your fluid type and tank size.
- Heating element material is also important. You don’t want the heating element’s material composition to negatively interact with the fluid.
- Keep it under control with a thermostat. Don’t assume your heater will run at the exact same temperature by just turning it on and off. Temperature control ensures that the elements don’t overheat and thermally damage your fluid.
- Don’t put a heater in an oil that is prone to oxidation, varnish. These oils are generally more sensitive to temperature fluctuations.
- Watch for fuel dilution of your oil. Send a sample BEFORE you turn on a heater to ensure there is no fuel in it. heating elements get very hot, and this could possibly ignite any fuel in the oil.
Summary
Bottom line, you should only use an immersion heater if it’s required for your unique operating situation. For example, winters in the northern hemisphere can be harsh with frigid temperatures of sometimes reaching -40C (-40F). Be sure to check with your OEM to make sure you’re fitting the right heater for your needs.
Plus, we recommend routine oil testing throughout the winter months (e.g. PLT1 test package which can monitor for oxidation and confirm if overheating is occurring) and in the spring to monitor for changes in oil condition due to overheating (e.g. PLT4 to test for varnish and oxidation). If you want to learn more, contact a Fluid Life representative today.