If you’ve been following our hydraulic systems blog for some time, you’ll already know that heat can be one of the most dangerous enemies for the hydraulic system. We’ve broken the reasons down to share with you the 3 most common, and you can see for yourself why even water or particle contamination is not as bad as energy contamination (ie heat).
1. Oil Life – Being familiar with Arrhenius’s Law tells us that every increase of 10°C will double the rate of reaction in hydraulic systems. When it comes to oil, there are chemical reactions that we don’t want – such as oxidation. Combine this with any air and water that is already in the oil and your oil will degrade to being in poor condition fast. You have probably witnessed this at home. When you pour oil into and heat it in a frying pan, it will rapidly go black.
2. Oil Viscosity – Keeping oil to its optimal operating viscosity will guarantee that there is good lubrication in addition to efficient power transmission. The hotter oil gets, the harder it is keep that viscosity.Imagine having a system that starts cold at 5°C but may operate up to 110°C. This window is so large that being able to maintain viscosity at a cold start of 800 centistokes and then at 25 centistokes for the maximum operating temperature will mean that you need an oil that has a viscosity index of 229. You’re not going to find this type of oil down at your local suppliers!
3. Seal and Hose Life – Although elastomers that are used for hoses and seals continue to improve with advancing technology, there is going to be some degradation from oil that is above 82°C . Operating with oil that is 10°C over the recommended temps are said to reduce the life of the seal by 80% or more.The continual cycle of heating and cooling already ages parts, but when the temperature extremes are larger, that happens more severely. Elastic properties are lost from polymers and that results in leaking.
At the end of the day, a machine that is running too hot can be very costly and it’s going to push up your hydraulic system overhead no end. It’s these details that will make all the difference to the bottom line of a business, and your management will thank you for it when you present them with annual savings.