I was contacted by a customer who processes crushed limestone. As expected, this generates a lot of dust that permeates everything in the area. If you’ve ever had dry walling done in your home you know what I mean.
The equipment used in this process utilizes extremely large and expensive air cylinders. Although wipers are installed to scrape the dust off the actuator rod as it retreats back into the cylinder, some of the abrasive limestone dust gets past or embedded into the wiper.
What gets past the wiper enters the cylinder and destroys the piston rings and the cylinder cannot hold pressure. What gets imbedded into the scraper scores the rod surfaces causing the seals to leak.
Several times a year the cylinders have to be taken apart, new piston rings installed and the rod sent out to be metalized and re-ground. The sheer size of these require a rigger to take them offline. Turn around time usually is a month. The process is time-consuming and expensive.
EXAIR suggest installing a model 2409 Air wipe around the shaft to blow the contaminants off the cylinder rod as it retracted into the cylinder. The customer reports that they can now go a year between rebuilds.