An immersion chiller conveyor runs continuously in cold, chlorinated water, with its shaft bearings submerged below the waterline. For one poultry processor, greased bronze bushings were a poor fit: the grease washed away within days, the bronze corroded, and replacing a bearing meant draining and re-sanitizing the trough. TriStar recommended a bearing designed specifically for submerged service.
What a Submerged Conveyor Bearing Has to Do
Mechanically, the demand on a chiller conveyor bearing is relatively light: a few hundred psi at very low surface speed, well within the capabilities of many bearing materials. The real challenge is the environment.
The bearing runs continuously submerged in chilled, chlorinated process water, typically around 34°F, inside a food-contact zone where lubricant cannot be allowed to migrate. At the end of each production day, equipment of this type is generally cleaned in place (CIP) with hot caustic and sanitizer.
A greased metal bushing is a poor fit for these conditions: lubricant can wash into the product water, chlorine can corrode the metal shell, and bearing wear can introduce debris into the food-contact environment.
Why Rulon 1439 Fits Submerged Service
TriStar recommended Rulon 1439, a white, FDA-compliant filled-PTFE material specifically suited to submerged service and offering better wear characteristics than most PTFE compounds. Because it is self-lubricating, there is no grease to migrate into the chilled water and no relubrication schedule to maintain in a wet, food-contact location.
With an operating temperature range of −400°F to +550°F, Rulon 1439 accommodates both the chilled operating environment and hot CIP cycle. It also withstands typical CIP solutions. Just as important on stainless equipment, TriStar’s FDA plane bearing grades can run against soft stainless hardware without causing abrasive shaft wear. The bearing remains the wear component by design, protecting the more expensive shaft.
Matching the Rulon Grade to the Conveyor
Rulon 1439 is one of four FDA-compliant Rulon grades stocked by TriStar, and the best choice depends on where the bearing is located on the processing line. While submerged and wetted positions point toward Rulon 1439, a dry conveyor bearing in a pharmaceutical or high-purity zone may be better suited to Rulon 641. It supports continuous non-lubricated service to 10,000 PV, and operates at temperatures up to +450°F.
Across the family, these self-lubricating materials can handle loads of roughly 1,000 psi and speeds up to approximately 500 fpm, wet or dry. That covers the great majority of conveyor bearing, wear strip, and guide applications. Because the parts can be machined to the existing envelope, conversion can take place during a normal bearing replacement—on an installed production line as readily as on a new build.
A Practical Retrofit for the Processing Line
For the poultry processor, the result is a Rulon 1439 bearing designed from the start for submerged operation: no grease in the chilled water, no bronze to corrode, and compatibility with daily CIP. On projected service, it replaces a short-lived bronze bearing that could only be changed by draining the trough. Facing a similarly difficult conveyor or food-processing bearing application? Contact our experts to review the operating conditions and determine the right material for the job.
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