Six Easy Steps to Maintain Your Hydraulic Equipment

My wife often asks me why I still do consulting work. She wonders why I happily leave the comfort of my office to crawl all over hot, dirty, smelly hydraulic equipment.

For starters, I actually enjoy it. Secondly, it keeps me sharp. But perhaps most importantly, it keeps me in touch with the issues that hydraulic equipment users must grapple with.

At the end of this meeting, we walked through the control room. Both the operating pressure and temperature were displayed on the default PLC screen - albeit along with a lot of seemingly more important production information. Say no more.

But could you answer these two basic questions about the vital signs of your hydraulic equipment, rebar tools, floor grinder, grouting pump? If not, I strongly recommend you make the effort to get to know your hydraulic equipment better.If the system is a closed-circuit hydrostatic transmission, mark a convenient location on each leg of the transmission loop and number those locations as 2 and 3. Skip this step for open-circuit hydraulic systems.

Next, mark a target on the heat exchanger inlet and outlet and number these 4 and 5, respectively. This records the temperature drop across the cooler. The benefit of this step is that if the oil flow rate through the exchanger and the temperature drop across it are known, the actual heat rejection of the exchanger can be calculated.

And if the system is overheating, knowing the actual heat rejection of the exchanger can help determine whether the problem is the result of an increase in heat load (due to an increase in internal leakage, for example) or whether the problem lies in the cooling circuit itself.

For example, if a hydraulic system with an input power of 100 kilowatts is overheating, and the actual heat rejection of the exchanger is 30 kilowatts, then the efficiency of the system has fallen below 70 percent. Therefore, an increase in heat load is the likely cause. On the other hand, if the exchanger is rejecting only 10 kilowatts of heat (which in this example equates to 10 percent of input power), then it's likely there is a problem in the cooling circuit or there is insufficient installed cooling capacity.