Blog Layout

The Best Spring Energized Seal Lip Styles For Every Project

Doug • September 17, 2021

Spring Energized Seals can be found in all kinds of applications across the spectrum of industries and sectors. While the pros and cons of the different spring types contained in the seal are often discussed, the style of sealing lips can also have a significant impact on performance.

Every spring type has at least 4 standard lip style options, so choosing the right style for your application is critical. There are a number of design factors that need to be taken into account to ensure the best option is chosen for the application.

Hardware configuration, seal installation direction, media type, and dynamic motion all need to be taken into consideration to correctly specify a lip type.

Eclipse’s team of experienced engineers is here to recommend the best design, whether standard or custom. Below we’ll discuss the basics of the common lip styles and where they’re used.

Standard Chamfered Lip Design

In Eclipse’s spring energized seal catalogs , the standard lip design is referred to as the LW style. It consists of chamfered lips on both the OD and ID of the seal. This lip style is suited for most general-purpose applications.

The chamfers make for easy seal installation and reduce the risk of damage in gland configurations where the seal must be installed face (spring side) first.

This can also be particularly important in blind installation situations. For example, when a rod seal is positioned in a groove that is located deep inside an assembly, there will be no way to externally guide the shaft installation through the seal.

But more than just lead-in chamfers for installation, the sealing point is carefully positioned to allow broad energizing from the spring. This extends wear life and helps promote consistent sealing performance throughout its service life.

Scraper Lips

The scraper lip design puts a sharp point on the leading edge of the sealing lip. It can be on either the ID or OD lip of the seal, or both lips depending on whether it’s a rod or piston seal application and the gland configuration.

The scraper lip puts a focused point contact between the seal and media allowing for wiping or excluding action. Scraper lips are often found where a seal is being used as an environmental barrier keeping outside debris or contamination from entering a system.

Scraper lips are also often employed in reciprocating applications sealing viscous media. A chamfered lip can potentially allow media to build up underneath the lip and cause a hydroplaning effect, allowing leakage. The scraper lip helps prevent this.

With a canted coil spring, the scraper lip can be “cut back” on the dynamic side of the seal. This shortens the lever arm of the lip and further concentrates the spring force. These designs are used when maximum scraping action is required.

The scraper lip is also used for seal retention in stepped glands. The sharp point locks in behind the barb of the stepped gland ensuring the seal is securely held in place. Often a step height of 0.020” or less is all that’s needed to properly retain the seal.

Radiused Lips

Sometimes called bubble or beaded lips, lips with a full radius are well suited for specific applications. The radius allows for a large contact area with the mating hardware. This extended surface contact creates a longer path for any leakage to penetrate thus providing excellent seal-ability in gas media.

The geometry also allows Eclipse to use special tooling and machining techniques when turning the seal jacket to provide a super finish on the surface.

When applied to Eclipse’s EZ030: Virgin Modified PTFE , the resulting finish can provide enhanced gas sealing performance and is often employed in cryogenics and other critical sealing applications.

Radiused lips can also be beneficial if the seal needs to pass over any ports or other irregularities in the hardware. The lack of any sharp edges and gradual radii will permit smooth transitions over hardware features. This minimizes the possibility of unnecessary seal damage.

Get a Custom Lip Configuration at Eclipse

Eclipse is by no means limited to the standard lip styles listed in our Spring Energized Seal catalogs. Our team of engineers is here to specially tailor the best sealing solution possible for your specific application.

While the lip styles we discussed serve well in many sealing systems, simple lip geometry changes can potentially yield large performance gains in areas such as leakage control and wear life.

Using a radiused lip in a scraping application will probably not work out well. Using a standard chamfered lip design to seal Hydrogen will likely be less than optimal.

If you’re utilizing a standard lip configuration and it’s leaving much to be desired, Eclipse is here to help.

By Doug Montgomery November 25, 2024
Eclipse has engineered sealing solutions for applications all over the planet and in a plethora of environments. From the bottom of the ocean to orbiting the earth, Eclipse is challenged by the unique conditions in each application. Whether it be extreme temperature and pressure or severely caustic or abrasive media, Eclipse has a solution for most every sealing problem. One distinct environment presents a particularly challenging set of circumstances for seal design – high radiation. Eclipse’s primary seal material choice for many applications is PTFE and PTFE blends. With all the wonderful attributes PTFE possesses as a seal material, radiation resistance is not one. In high radiation environments PTFE’s properties can degrade to essentially rule it out as a suitable material. The options for effective sealing materials that are also radiation resistant becomes very limited. The seal designer is therefore confronted with creating a seal that is expected to perform in every way a typical PTFE seal operates, out of materials that are not as favorable to sealing. This is where Eclipse’s engineering experience and expertise in seal design come to the forefront. The Client's Issue Eclipse was approached by a customer that was looking for a seal solution for a sensor used in a nuclear application. It would be operating in an environment with both high temperature and high Gamma radiation. Operating Conditions:
 Reciprocating Rod Seal
 Rod Diameter: Ø1.000
 Stroke: 1.5”
Cycle Rate: 2-4 cycles per minute
 Media: Air, Salt Water Mist
 Pressure: 100 PSI
 Temperature: 70° to 450°F
 Gamma Radiation Exposure: 10^6 rads
By Doug Montgomery November 14, 2024
Technological advancements in the area of robotics have led to more and more life-like creations existing only in works of science fiction a few decades ago. Development in autonomous logic processing and sensing allows bipedal robots to walk over uneven ground, up and down stairs, open doors and carry loads. Fast response to dynamic and unpredictable real-world environments is critical for the future use of robots in true-life service and practical employment in the years to come. While software and sensor development remain the primary focus of most research, the physical mechanics of next-gen robotics are also continually progressing. Physical components and control systems such as hydraulic pumps and cylinders, servo motors, and structural members are under pressure to continually be lighter, stronger, more efficient and less expensive. Increased demands on the physical components facilitate the need for innovative solutions in design and material usage. Advancements in construction and technology have spilled into all areas of robotic mechanisms and the many seals located throughout the system need to meet the challenges of tomorrow. Eclipse has been at the forefront of this research and has developed innovative solutions pushing the boundaries of conventional sealing devices. MicroLip™ by Eclipse is a prime example of most demanding applications forging new technologies in the sealing world. The Client's Issue Eclipse was approached by a leading robotics company looking for a sealing solution operating under a challenging set of conditions. While many components of tomorrow’s robotics are now controlled and actuated by servo/stepper motors and various electronic devices, the heaviest and most powerful movements are still driven by traditional hydraulics. The constant demand for more powerful hydraulic actuation in ever deceasing size and weight requirements has put tremendous strain on component design. But if robots are to progress to the point where they are usefully employed in the world, high power in a compact design is necessary. A robot, for example, used to survey and assist in a disaster zone too unstable for normal rescuers, must fit through doorways and over obstacles yet still be physically strong enough to render assistance. Large hydraulic systems are capable of moving extremely heavy loads but size and weight constraints of a humanoid size robot limit potential. The robot’s internal power supply to drive all components is also a limiting factor. Our client was developing a new hydraulic pump to drive all major motion aspects of their robotic systems. Their main objective was to minimize the pump’s physical size as much as possible while increasing output and improving power consumption efficiency. This means higher pressures and speeds on increasingly smaller and lighter components. Application Parameters: Shaft Diameter: Ø9.5mm Seal Housing Envelope: 5mm radial cross-section by 6mm axial width Rotational Speed: 3,500 RPM nominally; 6,000 RPM max Operating Pressure: 125 PSI min, 225 PSI nominal, 350 PSI max Surface Finish: 0.04µm Media: Hydraulic Oil While the above combination of pressure and speed might present difficulties for any conventional seal alone, the client’s extremely small physical envelope to house the seal further complicated the matter. If that wasn’t enough, the application presented the additional sealing challenge of up to 0.003” [0.08mm] of shaft runout. As part of the downsizing of all components in the pump, shaft support bearings were minimized leading to the possibility of runout. The wobbling effect of the shaft creates problems as the sealing lip has follow a moving, uneven mating surface, therefore potential leak-paths are created. Wear life can also be compromised due to higher concentrations of uneven loads. The combination of high pressure, high speed, high runout and minimal gland size present a worst-case scenario for a typical seal. Unsurprisingly, the client faced leakage of hydraulic fluid after only short periods of service with any conventional seal they had tested. Eclipse knew the had the perfect solution for this application. One developed to handle such extreme rotary sealing conditions: MicroLip™.
By Doug Montgomery October 14, 2024
How Eclipse reverse-engineered custom PTFE gaskets to restore a brewery’s historic equipment, ensuring leak-free connections and consistent, quality beer production.
By Doug Montgomery September 10, 2024
Custom piston seal rings by Eclipse enhance compressor performance, offering dry-run capability and extended wear life without hardware modifications.
Share by: