Recip Compressor: Piston & Rider Ring Wear

[RefineryRR]

Due to various reasons, our rod-drop measuring capabilities are not available. What would be the best way of tracking piston & rider ring wear for a study? Some have suggested using a feeler gauge to measure the top clearances but this only gives you the sizes of the outermost (crack-end) rings. What would be the best way of assessing the ring wear rates without rod-drop facilities?

The goal is to trend the ring wear & then extrapolate to predict the ring life.

 

[JJPellin]

The feeler gauge check would not be between the outermost piston ring and the cylinder bore. It would be between the top of the piston and the bore of the cylinder. Assuming that your cylinder is horizontally mounted and gravity works well where you are, this will give you an indication of rider band wear. As the rider band wears, the entire piston will drop and the gap at the top will increase.

It would probably be easier to measure the rod run-out. As the rider band wears and the piston drops, the run-out will increase. This can be measured with a dial indicator and does not require you to pull the outer head.

Johnny Pellin