Thinkstock
Hydraulicspneumatics 3530 June Troubleshooting Challenge
Hydraulicspneumatics 3530 June Troubleshooting Challenge
Hydraulicspneumatics 3530 June Troubleshooting Challenge
Hydraulicspneumatics 3530 June Troubleshooting Challenge
Hydraulicspneumatics 3530 June Troubleshooting Challenge

Troubleshooting Challenge: Regenerative Circuit Fails to Close

June 2, 2017
Test your engineering knowledge against this month's real-world problem.

Download this article as a .PDF

A large press uses a regenerative circuit to increase the closing speed of a ram. A pressure switch signals a PLC to close a logic slip-in cartridge valve so the ram can reach maximum tonnage. The press started having trouble developing enough tonnage when the logic valve did not close when Solenoid A was de-energized.

Technicians found the logic valve sleeve and poppet to be in good shape, and replacing the pilot valve did not fix the problem. They then removed the screw-in cartridge shuttle and found it damaged to the point that the floating ball was lodged in one end and would not move. They replaced the cartridge shuttle with a new one, but the new valve failed after only six to nine months of operation.

Any idea what was causing the failures?

Find the Solution

Think you know the answer to this month’s problem? Submit your solution via e-mail. All correct solutions submitted by July 3, 2017, will be entered into a random drawing for a $50 gift card. The winner will be notified, and his or her name will be printed in a future issue. Only one gift card will be awarded to any participant within a calendar year.

Congratulations to Nick Chasler, P.E., CMRP, Maintenance Reliability Engineer at Harley-Davidson Motor Co. A $50 gift card is in the mail to him.

Solution to Last Month’s Challenge:

Large-Plate Shear Problems

The shear blade problem straying from the backstops was caused by a lack of nitrogen pre-charge in the 2½-gal accumulator bladder. When the shear blade retracted, forcing the pullback cylinders to retract, a vacuum was caused in the rod areas, allowing air to enter past the cylinder rod seals. The cylinders were full of air, which allowed the blade to pull away from the backstops. 

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...