Combining two components into a single part while maintaining part function and life was accomplished by Minnesota Rubber and Plastics with a redesigned piston V-cup seal. Used in fuel assembly applications, these new seals provide improved seal life while reducing manufacturing and assembly costs.

The original two-part design was functionally satisfactory but overly complicated by today’s standards. The two components acted as a horizontal dynamic piston seal with the sealing function occurring for pressure traveling in either direction – in and out. Two parts were stacked back-to-back to accomplish this bi-direction sealing process. This seal worked well enough without trapping pressure between the seal surfaces. However, the assembly process to achieve the seal consistency was labor intensive, requiring skillful part handling and placement as well as special testing.

In a joint customer/supplier program, Minnesota Rubber and Plastics brought to bear its six decades of experience with fluid sealing applications in harsh operating environments. Minnesota Rubber and Plastics developed a new, single V-cup seal design that simplified and sped up the assembly process, resulting in improved efficiencies, reduced labor content and lower costs.

Minnesota Rubber and Plastics material selection for this seal was also critical to the success of the single part design. A special fuel resistant fluoroelastomer material was formulated so that the part would withstand the harshness of extended fuels. In addition to providing the needed fuel resistance, the fluoroelastomer provided excellent flex fatigue resistance, excellent compression set, and most important, lower cost.

Produced in automated presses, just-in-time volume requirements were met while the new, single part cost was 23 percent less than the previous two part assembly. Delivery time was shortened while part quality and repeatability was enhanced because of the one piece design.

Minnesota Rubber and Plastics
www.mnrubber.com