Piston Rings

Splits, fractures, crumbles and wear.

Usually inadequate maintenance is the cause. Did you apply the planned preventative maintenance programme the equipment manufacturer recommended?

If it is a refrigerant compressor, liquid in the suction line can cause damage from hydraulic shock or sudden cooling.

Also, not enough refrigerant in the suction = hi suction temp = hi discharge temp = oil breakdown = bad stuff after that! -- JHF

you can't compress liquid, do avoid that and the rings last longer

"failures and causes of piston rings in reciprocating compressor"

Failures can be many things, some already mentioned, many more to be discovered by searching for the answer yourself.

Causes are to seal the compressor piston against walls.

metal or non-metallic? How about a picture?

How did you determine that the piston rings failed?

• Excessive oil consumption
• Oil in discharge air which can also be caused by deposits on the piston rings
• Abnormal noise during operation

No failures have been reported.

Could be an interview question ,or just idle curiosity, for all we know.

The most reliable method I can think of to cause a piston ring to fail requires a projectile with enough kinetic energy and momentum to pierce the cylinder wall and impact the piston ring.

Insufficient ring end gap and/or overheating can cause the ends to butt, leading to seizure in the cylinder, broken rings, fractured pistons (land separation), and several other problems.

Piston moves back and forth inside the cylinder. Piston ring is meant to give leak-tight joint between the stationary cylinder and moving (reciprocating) piston. In this contest, the main failure and cause are:

Failure: Piston ring is not giving leak-tight joint.

Cause: Abuse.

To get root-cause, keep expanding the primary cause by asking 'why', and again ask 'why' till you don't need further asking…

You didn't say whether it was a lubed, mini-lubed or non-lubed design recip. Failure of the lubricant system would be my first guess if it was a lubed or mini-lubed recip.

You also didn't state whether it was a vertical or horizontal cylinder design which could also lead one to different issues of failure based on that design difference.

Someone shutting the outlet without proper relief valves being installed could lead to overpressure and possibly damage the rings due to blow-back.

What type of failure?

Cracked rings?

Worn rings?

Scuffed rings?

Blued rings?

Need more info.