Designing Floating Backup Rings for High Pressure Rotary Sealing
As the worldwide leader in high pressure rotary sealing with polymeric seals, Kalsi Engineering offers training on how to design its patented floating backup rings. This engineering-related training is free to existing licensees of the technology and is geared for the mechanical engineers and designers who are responsible for designing the licensee’s high-pressure equipment. This training can be provided at your facility or ours, or via web conference, and lasts approximately two hours. Contact our staff to schedule the training, or to learn more about our high-pressure rotary seal technology and licensing opportunities.
The Introduction and Overview Portion of the Training
The training begins with a brief introduction to Kalsi Engineering, to orient individuals who are unfamiliar with the company. This is followed by a brief introduction to the principle of operation and characteristics of the general type of high-pressure rotary seal designs that are typically used with floating backup rings. After a discussion of the challenges involved in implementing high-pressure rotary seals, the features, benefits, and operation of the floating backup ring are presented. Also included is a discussion of how a high-pressure oil seal mounted in a floating backup ring can be paired with a partitioning seal to retain a process fluid.
The Detailed Engineering Portion of the Training
The detailed engineering portion of the training presents the backup ring design process in logical sequence, beginning with a discussion of the rotary shaft. Topics include analysis of pressure-related shaft deformation, shaft tolerance and surface finish requirements, wear resistant hard coatings, and designing the seal installation path (including the installation chamfer).
Once the diameter, tolerance, and pressure-related deformation of the shaft are established, the design of the remaining components of the assembly can proceed. This part of the training commences with a review of the factors that need to be considered when designing the length and bore diameter of the backup ring, and related dimensional tolerances.
This is followed by a description of how to design the radial depth of the backup ring, beginning with the factors to be considered when estimating the anticipated maximum level of lateral shaft deflection. This estimate paves the way for the remaining calculations that affect the outer diameter of the backup ring. Factors influencing backup ring material selection are also discussed, including the use of insert-type journal bearings in steel backup rings.
Next comes a discussion of the torsional deflection analysis of the backup ring, and a review of the design features that are iteratively adjusted to limit and optimize torsional deflection. If desired, the pressure-related deformation of the backup ring bore can be matched to the pressure-related deformation of the shaft, to minimize extrusion gap clearance and maximize journal bearing engagement.
The training also covers the design of other components of a floating backup ring assembly including the pressure bulkhead, retainer, and anti-rotation feature, and a review of appropriate surface finishes and tolerances.
Training Objectives
This training is recommended for seal customers who require the highest-pressure capability and longest seal life. At the conclusion of the training, your engineers and designers should understand the features and benefits of the floating backup ring and should have a reasonably complete understanding of how to design and dimension a floating backup ring for extreme high-pressure rotary sealing. In addition to teaching our licensees how to design floating backup rings, our experienced engineers are also available to provide a detailed review of the resulting licensee-engineered backup ring designs.
Click here to review a complete list of Kalsi Seal-related training classes.
