Need rotary seals fast? Check out our online store.
The custom-engineered Bal Seal® rotary shaft seal sets new standards for performance and reliability in rotary and oscillating applications. Precision machined from PTFE and other premium polymers, our spring-energized seal combines innovative geometries with a wear-regulating canted coil spring energizer to extend the service life of the critical equipment you design.
What Is a Spring-Energized Rotary Seal?
A spring-energized rotary seal is a precision-machined polymer seal reinforced by an internal spring element that maintains constant contact force against a rotating shaft. Unlike conventional elastomeric seals or standard O-rings, spring-energized rotary seals use a canted coil spring, helical spring, or cantilever spring to compensate for wear, thermal expansion, and hardware tolerances — delivering consistent sealing performance over an extended service life.
Bal Seal® rotary shaft seals are custom engineered from PTFE, PEEK, UHMWPE, and other advanced fluoropolymer and thermoplastic materials. Each seal design is optimized for the specific speed, pressure, temperature, and media requirements of your application, making them ideal for environments where standard sealing solutions fall short.
Why Choose a Spring-Energized Rotary Seal?
Engineers across aerospace, medical device, energy, semiconductor, and industrial equipment industries choose Bal Seal® spring-energized rotary seals for applications where conventional seals cannot meet performance demands.
Low Friction & Reduced Wear
PTFE-based seal jackets combined with precisely engineered spring energizers exhibit exceptionally low friction coefficients. This reduces heat generation at the sealing interface and extends both service life and equipment uptime — critical in high-speed rotary applications up to 3,000 ft/min.
Broad Chemical & Temperature Resistance
Our rotary seals operate reliably across a temperature range from cryogenic conditions to over 600°F. Advanced polymer formulations and filled PTFE compounds resist aggressive chemicals, solvents, gases, and hydraulic fluids without degradation.
Vacuum & High-Pressure Sealing
Bal Seal® rotary seals are engineered for vacuum-compatible sealing down to 10⁻⁸ Torr and high-pressure environments exceeding 20,000 PSI. Custom seal geometries with anti-extrusion features maintain integrity under the most demanding pressure differentials.
Rotary Shaft Seal Profiles
When you’re sealing in rotary applications, speed is a primary consideration. Here’s a sampling of the thousands of profiles we’ve engineered for specific speed requirements.
High Speed Sealing
Designed for speeds up to 3000 ft./min, this seal features a metal locking ring that prevents rotation and promotes consistent sealing contact in thermal cycling conditions.
Medium Speed Sealing
Designed for speeds of 750 ft./min, this seal employs an O-ring on the outer diameter. A canted coil spring energizer maintains a constant sealing force against the shaft.
Low Speed Sealing
This seal features a dynamic single contact lip that helps reduce friction and heat build-up at speeds up to 250 ft./min. Its design also allows for press-in mounting.
Designs are provided as examples only. By precisely adjusting lip and heel geometries, energizer forces, and material formulations, we’ll create a solution that meets your unique rotary sealing requirements.
Rotary Shaft Seal Materials
The Bal Seal® spring-energized rotary seal gives you the ability to closely control frictional forces and optimize sealing effectiveness in a broad range of chemicals, temperatures, and pressures. Base jacket materials consist of polytetrafluoroethylene (PTFE), polyethylene (PE), polyetheretherketone (PEEK), and other specialty polymers. We combine these with advanced filler materials to enhance performance properties. Here’s a small sampling of the materials we’ve formulated for specific rotary application requirements.
Excellent wear resistance in various gases, Low abrasion to dynamic surfaces and soft mating materials (aluminum, mild steel, brass, plastics), FDA compliant
Light-duty service, Low friction, Very good chemical compatibility, Good wear resistance in liquids, humid conditions
Severe service conditions, Excellent performance in applications with high pressure, low speed, and high temperature
Severe dry and liquid service, Excellent wear and extrusion resistance in liquids, inert gases, and vacuum
Superior heat and wear resistance, Performs well in high or low speed applications when running against soft metals
Ideal for contact with housings made from soft metal or plastic, Performs well in high-speed, low pressure applications
Light-duty service, Low friction, Excellent chemical compatibility, FDA compliant
High purity, High wear resistance in water and aqueous solutions, FDA compliant
Ideal for bearing seals and backup ring applications, Tolerance for high temperatures and pressures, Excellent chemical compatibility
Rotary Shaft Seal Energizers
At the heart of almost every Bal Seal® rotary seal is an energizer that’s precision-engineered to promote even wear and longer seal service life. Choosing the right energizer – with the ideal combination of force, fit, and finish – is as critical to the success of your design as the seal material itself.
Bal Spring®
Canted Coil Spring Energizer
Friction: Low
Sealing Force: Low
Bal Spring®
Canted Coil Spring Energizer
Friction: Moderate
Sealing Force: Moderate
Bal Spring®
Canted Coil Spring Energizer
Friction: High
Sealing Force: High
Bal Spring®
Helical Spring Energizer
Friction: High
Sealing Force: High
Bal Spring®
Cantilever Spring Energizer
Friction: High
Sealing Force: High
Elastomeric O-Ring Energizer
Friction: High
Sealing Force: High
Spring Energizer Force
The Bal Spring® canted coil spring exhibits a unique deflection and force behavior when it’s compressed. Unlike typical spring technologies, our spring exerts a near-constant force across the working deflection range, and its forces remain consistent – even in wide temperature ranges. It resists compression set, and its individual coils compensate for misalignment, tolerance variations, and surface irregularities.
A variety of spring energizer materials are available to meet chemical, temperature, and galvanic compatibility requirements
STAINLESS STEEL (302, 316, 316L) | MP35N® | PLATINUM IRIDIUM | TITANIUM | HASTELLOY® | INCONEL® | BERYLLIUM-COPPER | ZIRCONIUM-COPPER
Rotary Shaft Seal Sizes
We produce our Bal Seal spring-energized seals for rotary applications in sizes ranging from 0.020 in. (.508 mm) to 120 in. (304.8 cm) inside diameter.
Rotary Shaft Seal Service Conditions
Temperature, pressure, speed, and media. These are just a few of the major factors you’ll need to consider when choosing a seal for rotary applications. Our nearly limitless combination of seal materials, energizers, and geometries – coupled with our consultative engineering approach – will help you address all of them, and create a solution that sets your designs apart. Here’s a look at how our Bal Seal® spring-energized seal performs under a variety of conditions.
Pressure Resistance
(thousand pounds per square inch)
Vacuum Resistance
(Torr)
Temperature Resistance
(° fahrenheit)
Surface Speed
(feet per minute)
Frictional Values
(at ambient temperature)
Seal Media Compatibility
Locking & Anti-Extrusion Devices
For applications requiring an added level of protection, we can integrate an engineered metal locking ring into the Bal Seal® spring-energized seal design. The locking ring prevents rotation of the seal in the hardware, and it promotes consistent sealing contact under thermal cycling conditions. Backup devices made from PEEK and other materials can be designed to integrate with the seal jacket geometry, or they can be provided as separate parts.
Rotary Seal Industry Applications
Bal Seal® custom rotary shaft seals are engineered to solve the most demanding sealing challenges across a range of critical industries. Our consultative design approach ensures each seal is optimized for the unique operating conditions of your application.
Aerospace & Defense
Flight-critical hydraulic actuators, fuel systems, turbine engines, and environmental control systems rely on our temperature-resistant and vacuum-compatible rotary seals to perform in extreme conditions.
Medical Devices
Surgical handpieces, diagnostic instruments, drug delivery systems, and implantable devices demand precision seals with biocompatible, FDA-compliant materials and ultra-low particle generation.
Semiconductor & Analytical
Wafer processing, vacuum chambers, chromatography, and mass spectrometry equipment require chemically resistant rotary seals with ultra-clean materials and exceptional vacuum integrity.
Oil, Gas & Energy
Downhole tools, rotating equipment, compressors, and turbines operate under extreme pressures and aggressive media — conditions where our high-pressure, wear-resistant seals excel.
Industrial & Fluid Power
Hydraulic and pneumatic cylinders, pumps, valves, and rotating shafts across general industry benefit from our low-friction PTFE seals that reduce maintenance intervals and extend equipment uptime.
Food, Beverage & Pharma
FDA-compliant and USP Class VI materials ensure our rotary seals meet the stringent purity and cleanliness standards required in pharmaceutical processing, food-grade equipment, and clean-in-place systems.
Rotary Shaft Seal FAQs
A rotary seal is designed to maintain a barrier between a rotating shaft and a stationary housing, accommodating continuous or oscillating motion. A static seal, by contrast, seals between two surfaces with no relative movement. Rotary seals require specialized lip geometries, low-friction materials like PTFE, and precisely engineered spring energizers to manage heat, wear, and dynamic contact stress — considerations that static seals do not face.
Bal Seal® rotary shaft seals are precision machined from advanced polymers including polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), ultra-high molecular weight polyethylene (UHMWPE), and specialty fluoropolymers. These base materials can be filled with graphite, carbon fiber, molybdenum disulfide, glass, and other additives to optimize wear resistance, friction, chemical compatibility, and temperature performance for your specific application.
Bal Seal® spring-energized rotary seals are engineered for surface speeds up to 3,000 feet per minute, depending on the seal profile, material, and operating conditions. Our high-speed seal designs incorporate metal locking rings and optimized lip geometries to manage heat buildup and prevent seal rotation in the hardware at elevated speeds.
Yes. Bal Seal® rotary seals are engineered for both vacuum environments down to 10⁻⁸ Torr and high-pressure service exceeding 20,000 PSI. Custom jacket geometries with anti-extrusion heel designs and backup rings ensure seal integrity across the full pressure spectrum. Canted coil spring energizers maintain consistent sealing force regardless of pressure direction.
A canted coil spring is a garter-type spring with individual coils set at an angle (canted) relative to the spring’s axis. When used as a seal energizer, the canted coil spring provides near-constant radial force across a wide deflection range, compensating for wear, thermal expansion, and hardware tolerances. This unique force-deflection behavior is a key advantage over conventional helical springs and O-ring energizers, enabling longer seal service life and more consistent sealing performance.
Selecting the right rotary seal requires evaluating shaft speed, system pressure, operating temperature range, media compatibility, and hardware materials. Bal Seal engineers work directly with your design team through a consultative process to optimize seal profile geometry, jacket material, filler compounds, and energizer type for your unique requirements. Contact our engineering team to start the design process.
Request Rotary Seal Engineering Support
Every Bal Seal® rotary shaft seal is custom engineered for your specific application. Our seal design experts will evaluate your operating conditions — speed, pressure, temperature, media, and hardware — and recommend a solution optimized for performance and service life. Whether you need a single prototype or high-volume production, our precision seal manufacturing capabilities deliver the quality and consistency your designs demand.
Technical Resources
Product Catalog
Industry Guide
Technical Report
