Production line

Troubleshooting Challenge: Flow Control Overheating on a Food Processing Line

March 18, 2020
Try your hand at solving this month's head-scratcher.

In the food processing industry, extra care is taken to ensure hydraulic oil does not find its way into the product. The circuit shown is one that had air causing the cylinder to drift, creating a problem with the autocycle sensors. Notice the extra rod-gland drain line. It lets operators see if the seal was leaking and replace it before it became a problem. The long lines with 50-psi check valves were used to make sure oil leaving the cylinder returned to the tank for filtering and fresh oil was making it to the cylinder. The production line was on the first floor with the power unit in the basement

Recently, the customer had a problem with the rod-end meter-outflow control getting so hot the paint was peeling off it. The maintenance crew was new to this part of the plant and did not know much about the original design. After a new flow control did not fix the problem, their next solution was to install a heat exchanger.

Any idea what caused the overheating?

What’s the Problem?

Think you know the answer to this month’s troubleshooting problem? Then email your answer to [email protected] (put “March Troubleshooting” in the Subject line.) All correct answers received by April 30 will be entered in a random drawing. The winner will be mentioned in a future column.

Solution to Last Month

Ink Mixing Machine’s rpms Fluctuate Out of Limits

The ink mixer speed problem was caused by a pump and/or motor that had excessive wear.

As the dry chemicals were added, it required additional pressure to turn the mixing blades which in turn increased the leakage in the pump/motor units. As liquid was added, it thinned out the mixture, lowering the pressure which caused the leakage to reduce increasing the speed. Typically, when there is wear-and-tear in hydrostatic system, both pump and motor should be reconditioned or replaced.

Gregory J. Palet of Minocqua, Wisc. got the February solution first. Congratulations!

Robert J. Sheaf Jr., is founder and president of CFC Industrial Training, a division of CFC Solar, which provides technical training, consulting and field services to any industry using fluid power technology. Visit for more information.

About the Author

Robert Sheaf | President

Robert J. Sheaf Jr., is the founder and president of CFC Insustrial Training, formerly Certified Fluid Consultants, part of CFC-Solar Inc. CFC-Solar provides technical training, consulting, and field services to any industry using fluid power technology. 

Continue Reading

BOOK 2, CHAPTER 12: Fluid Motor Circuits

March 18, 2009
Table of Contents

Motor leakage variations

Oct. 18, 2006
affect low-speed performance

Sponsored Recommendations

7 Key Considerations for Selecting a Medical Pump

Feb. 6, 2024
Newcomers to medical device design may think pressure and flow rate are sufficient parameters whenselecting a pump. While this may be true in some industrial applications, medical...

How Variable Volume Pumps Work

Feb. 6, 2024
Variable volume pumps, also known as precision dispense pumps, are a positive displacement pump that operates by retracting a piston to aspirate a fluid and then extending the...

What is a Check Valve and How Does it Work?

Feb. 6, 2024
Acheck valve, a non-return or one-way valve, is a mechanical device that allows a gas or liquid to flow freely in one direction while preventing reverse flow in the opposite ...

The Difference Between Calibrated Orifices and Holes

Feb. 6, 2024
Engineers tasked with managing fluid flow talk about both holes and calibrated orifices, but they are two distinct entities. A hole can be any opening, but a calibrated orifice...