Using Air-Oil Lubrication for Slab Casters

Dave Stoyanoff, DropsA USA
Tags: bearing lubrication

Grease systems have long been popular in lubricating bearings located in the spray chamber of a caster. However, the harsh and steamy environment leads to an influx of water into the bearing between grease lube cycles and eventually destroys it.

Air-oil not only lubricates but also pressurizes the bearing cavity, preventing water and dirt ingress from happening.                     

Installation of air-oil systems at several U.S. steel mills has resulted in a substantial increase in bearing life. All mills have reported an improvement in their number of slab heats. One steel mill in particular has experienced an increase from 1,200 heats with grease to more than 9,000 using air-oil over the past eight-plus years.    

A typical air-oil system consists of the following:

 Reduced bearing costs are just one of the advantages of the air-oil system. Other positives include:

Typically, a system includes a pump to automatically feed a number of dual-line air-oil distributors mounted on each segment feeding the roll bearings. An oil-pressure switch provides monitoring of both oil lines, while an air-pressure switch monitors the air-supply pressure. System operation and diagnostic feedback are handled by a dedicated controller or in the programmable logic controller (PLC) brains servicing the caster pulpit.

Dave Stoyanoff is the general manager of DropsA USA Inc., with more than 35 years of experience in hydraulic and lubrication systems. He is based out of Sterling Heights, Mich. For more information, visit the DropsA website at or contact Dave via e-mail at or by phone at 586-566-1540.