Most Common Pneumatic Cylinder Issues

Pneumatic cylinders used in industrial applications or in heavy machinery, for instance, often face extremely demanding working conditions. They are constantly moving, often fast and under tremendous force.

Problems can vary according to the type of pneumatic cylinder and application, but there are some common signs you may see that indicate the need for air cylinder repair:

1.Failure to move (or actuate). Lack of movement is a clear sign that something is wrong. Monitoring actuating pressure can help avoid system breakdown.
2.Actuating too slowly.
3.Requiring higher than normal pressure to actuate. If pilot control pressure is too low, the control line may be too small or the metering choke valve could be malfunctioning. Also, there may be mechanical binding between the working load and the air cylinder, so check to make sure that the parallelism is maintained.
4.Visual corrosion or excessive wear.
5.Hissing noises.
6.Load pulsing. Air cylinders are known for their smooth, almost silent movement. If you notice a change, it’s probably not running right.
7.Intermittent start-up. When cylinders run at overload capacity, seals are subjected to higher stress and friction rates. Rod ends bend or break, and actuators can come apart. In a system with speed control or energy-absorbing devices, pressure spikes can also occur above normal system pressures.

These issues can be caused by:

1.Incorrect air supply — either too much air or low air pressure due to leakage
2.Loose tie rods, cables, mechanical or magnetic coupling
3.Worn, cracked, or torn seals
4.Contamination (dirt or moisture)
5.Off-center loads

Sometimes, There’s a Relatively Easy Fix
In some cases, you will have to disassemble and reassemble the air cylinder, but repairing or replacing components can often keep downtime to a minimum and prolong the life of the cylinder. That gives you the best return on your investment. For this reason, W.C. Branham offers field repair kits for our cable cylinders, U-SA rodless pneumatic cylinders, as well as our DURATRK, and MAGTEC rodless cylinders. We recommend you stock a kit for each type of cylinder you’re using, so you can make repairs as quickly as possible.

But we all know the best offense is a good defense. So establish a regular schedule for inspections and preventive maintenance. Clean equipment performs best and lasts the longest. Detecting and fixing small problems before they cause productivity problems or outright failures saves money and prevents costly downtime.

Always make sure the power supply is off and any leftover air has been released before beginning your pneumatic cylinder repair. This is a critical safety issue. Inspect the cylinder, tube, and rod seal – these are the most vulnerable components. Replace seals or make other repairs as soon as you detect damage.

Lubricate the following components, as necessary:

1.Piston outer surface and rod surface
2.Piston seal groove, plus the inner and outer surface
3.Rod seal
4.Rod seal groove on the rod cover
5.Tube gaskets
6.Tube inner surface

Sometimes, It’s Better to Invest in a New Cylinder

If you find extensive damage to your pneumatic air cylinder, it’s probably time to replace the unit instead of trying to repair it. However, if you’re having repeat problems, you may be using the wrong pneumatic cylinder.