10 | January/February 2010 www.ifps.org | www.fluidpowerjournal.com www.ifps.org | www.fluidpowerjournal.com January/February 2010 | 11

The Michigan foundry had been experienc-ing excessive cylinder failures on its large in-dex conveying mold line for a number of years that had a negative effect on manufacturing uptime and maintenance budget. The cylin-ders used in this application were a series of either two or four hydraulic cylinders located in each corner of the long rectangular-shaped conveyor system that either pushed or re-ceived large molds, each weighing anywhere from 210,000 lbs. to 350,000 lbs., filled with molten steel used to make the castings. Once a mold was received by the cylinders at the end of the conveyor line, it was then pushed off in another 90-degree direction with 3¼” bore × 74”-long stroke hydraulic cylinders. Each cylinder had a 2½” piston rod diameter that was connected to a heavy, large round slug of steel necessary to receive and push the molds.

The long cylinder stroke had to be smooth with no jerking or hesitation in or-der to not disturb the molten steel encased within each mold. In the past, typical cyl-inder problems included the failure of all dynamic seals, excessive piston rod scoring, severe rod bearing wear, piston fracturing, and tube scoring. During this time period, according to facilities maintenance records, the foundry was either repairing or pur-chasing an average of 103 cylinders per year just for this pusher/kicker cylinder applica-tion on its index conveying system; 30% of the time these cylinders were replaced dur-ing manufacturing run time, which resulted in a loss of production. The weight of the piston rod and the heavy steel attachment, combined with the long cylinder stroke, was a contributing factor to the cylinder failures they were experiencing. Unfortunately, con-ditions did not allow for engineering a way of guiding the piston rod through its stroke travel to minimize the forces exerted upon the piston rod, the bearing cartridge, and other cylinder components.

The company needed a cylinder that could hold up and perform in this harsh manu-facturing environment. Peninsular Cylinder Company was contacted to examine this and other cylinder-related applications and to ad-dress the problem of cylinder failure in the destructive foundry environment. Peninsu-lar’s engineering group worked with the East Jordan maintenance department to identify root failure causes and to provide cylinder design enhancements that would correct and minimize prior cylinder failure.

Every aspect of the application and result-ing cylinder failure was examined, evaluated, and subsequently corrected by incorporating internal design enhancements and upgrading cylinder features to increase the assurance of longer cylinder life within these trouble-some applications. Cylinder enhancements included the use of dual piston stop spool design with high-strength wear bands for in-creased stability and durability; a specially hard coated and lubristic “slip-tuff” rod bear-ing cartridge was provided in addition to hard chrome plating the I.D. of the cylinder tube. In addition, Carboxylated Nitrile seals were

used in lieu of standard Buna-N seal material. Special attention was also paid to all cylinder concentricity and tolerances.

The end result since making the above changes and engineering improvements was that East Jordan Iron Works significantly re-duced its maintenance costs. Approximately 80 cylinders are now either not purchased or repaired, as was before on a yearly basis, for just this one destructive application. In ad-dition, run time has substantially increased, resulting from the elimination of cylinder failure during manufacturing uptime periods. To further complement the reduced main-tenance cost effort, Peninsular developed a cylinder tracking system, monitored by both

Peninsular and East Jordan Iron Works, at both the Michigan and Oklahoma facilities. This system identifies the last repair date or procurement date of any cylinder in need of repair and provides a critical tracking mecha-nism for maintenance personnel to identify cylinder costs within all of the various plant-wide applications, in addition to identifying when a cylinder should be scrapped out for a new replacement.

For more information, contact Peninsular Cylinder Company, Inc.

at 800-526-7968, by e-mail: sales@peninsularcylinders.com,

or on the Web: http://www.peninsularcylinders.com.

Cylinders

Solve Tough Foundry Application ProblemS

Fluid Power Case study

By Brent PatersonPresident, Peninsular Cylinder Company

Everyone connected with fluid power and industrial manufacturing knows just how destructive steel mill and foundry applications are on the manufacturing systems and

components used within plants to produce steel. One such company is East Jordan Iron Works, with facilities located in East Jordan, Mich., and Ardmore, Okla. Both foundries produce infrastructure castings such as manhole covers and frames, fire hydrant castings, valves, and many other casted products for use in industrial applications and in cities throughout the United States and abroad.

Foundries can be dirty places that contain harsh manufacturing environments for all of the mechanical components in the plant. Just ask the East Jordan Iron Works maintenance team from East Jordan, Michigan.