Rotary Seals

The custom-engineered Bal Seal® spring-energized seal sets new standards for performance and reliability in rotary and oscillating applications. Precision machined from PTFE and other premium polymers, our seal combines innovative geometries with a wear-reducing spring energizer to extend the service life of the critical equipment you design.

Rotary 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.

Bal Seal® high-speed rotary sealing diagram
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.

Bal Seal® medium-speed rotary sealing diagram
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.

Bal Seal® low-speed rotary sealing diagram

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 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.

Modified PTFE Rotary Seal Material

MODIFIED PTFE
(TA = WHITE)

Excellent wear resistance in various gases, Low abrasion to dynamic surfaces and soft mating materials (aluminum, mild steel, brass, plastics), FDA compliant

Graphite Filled PTFE

GRAPHITE-FILLED PTFE
(G = BLACK)

Light-duty service, Low friction, Very good chemical compatibility, Good wear resistance in liquids, humid conditions

Graphite Fiber-Reinforced PTFE

GRAPHITE FIBER-REINFORCED PTFE
(GFP55 = BLACK)

Severe service conditions, Excellent performance in applications with high pressure, low speed, and high temperature

Moly Disulfide-filled PTFE

GRAPHITE FIBER AND MOLY DISULFIDE-FILLED PTFE
(GFPM = BLACK)

Severe dry and liquid service, Excellent wear and extrusion resistance in liquids, inert gases, and vacuum

Polymer-filled PTFE SP-5

POLYMER-FILLED PTFE
(SP5 = LIGHT BROWN)

Superior heat and wear resistance, Performs well in high or low speed applications when running against soft metals

Polymer-filled PTFE SP-45

POLYMER-FILLED PTFE
(SP45 = LIGHT GRAY/GREEN)

Ideal for contact with housings made from soft metal or plastic, Performs well in high-speed, low pressure applications

Polymer-filled PTFE SP-191

POLYMER-FILLED PTFE
(SP191 = TAN)

Light-duty service, Low friction, Excellent chemical compatibility, FDA compliant

BLENDED POLYETHYLENE
(UPC16 = TRANSLUCENT WHITE)

High purity, High wear resistance in water and aqueous solutions, FDA compliant

UHMWPE UP-30

UHMWPE
(UP30 = GOLD)

Suitable for very high pressure, low speed, FDA compatible

High-performance PEEK with Carbon Fiber and PTFE P69-D HT

HIGH-PERFORMANCE PEEK WITH CARBON FIBER AND PTFE
(P69D HT = BLACK)

Ideal for bearing seals and backup ring applications, Tolerance for high temperatures and pressures, Excellent chemical compatibility

Rotary 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 (low)
Bal Spring®
Canted Coil Spring Energizer

Friction: Low
Sealing Force: Low

Bal Spring® canted coil spring energizer (medium)
Bal Spring®
Canted Coil Spring Energizer

Friction: Moderate
Sealing Force: Moderate

Bal Spring® canted coil spring energizer (heavy)
Bal Spring®
Canted Coil Spring Energizer

Friction: High
Sealing Force: High

Bal Spring helical spring energizer
Bal Spring®
Helical Spring Energizer

Friction: High
Sealing Force: High

Bal Spring® cantilever spring energizer (heavy)
Bal Spring®
Cantilever Spring Energizer

Friction: High
Sealing Force: High

Elastomeric O-Ring Energizer
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.

Spring Energizer Force Chart

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 Seal Sizes

We produce our Bal Seal spring-energized seals for rotary applications in sizes ranging from from 0.030 in. (.762 mm) to 120 in. (304.8 cm) inside diameter.

Rotary Seal Sizes

Rotary 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)

Rotary Seal Pressure Resistance

Vacuum Resistance
(Torr)

Rotary Seal Vacuum Resistance

Temperature Resistance
(° fahrenheit)

Rotary Seal Temperature Resistance

Surface Speed
(feet per minute)

Rotary Seal Surface Speed

Frictional Values
(at ambient temperature)

Bal Seal® Seal Frictional Values

Seal Media Compatibility

Rotary Seal Service 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.

Locking Anti-Extrusion Devices

Rotary Seal Applications

Technical Resources

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