Category Archives: Eclipse Engineering

Eclipse Announces MicroLip™ Prototype Program

picture of microlip rotary

Eclipse has been working hard during the Covid-19 downtime on finding solutions to issues that customers have brought to the table over the past few years.

Many new designs have been sent into testing while focusing on processes that will help improve productivity and lower costs.

The MicroLip™ is an example of a viable solution to rotary seal issues that many customers have struggled with. This is especially true when the order volumes are relatively low or the shaft diameters are small, such as with encoders or chemical-processing facilities.

The Eclipse MicroLip™ Prototype Program

When moving from rubber to Teflon lip seals, Eclipse has found that the cost to bring the product to market is often a hindrance. The high cost is due to tooling and the number of pieces that must be manufactured to make the product viable in the prototype phase.

Because of this, many customers sneak by using inappropriately-applied rubber lip seals to solve rotary seal problems.

MicroLip™ seals have proven to be a powerful component in rotary services. Since the MicroLip’s inception, it has been applied to a variety of applications including mobile hydraulics, robotics, surgical drills, and semiconductor processing and encoders.

Over the last 3 years, Eclipse has designed and manufactured various styles of MicroLips in diameter sizes of under 1/8 inch (5mm) and over an inch. Since the components of the MicroLip™ can be machined, Eclipse has made the seal in quantities of less than 10, and batches in the thousands. Continue reading Eclipse Announces MicroLip™ Prototype Program

Designing Cryogenic Seals for High and Low Temperature Sealing

cryogenic

When designing for low temperature sealing, the first step is to define the temperature range that the seal will be operating in.

Typically, cryogenic as seals are those that are operating below -65 Fahrenheit. Gallagher’s partner, Eclipse, chooses this benchmark because they currently have elastomers that have a usable TR10 value at this temperature.

When designing at this level — with high temperatures around 300 Fahrenheit — an understanding of what level of leakage control is required on the low temp end. Seals that operate in aircrafts must function within this range.

However, there may be an allowable leakage rate which allows for reduced drag. When requiring zero leak, the drag in the system is often increased to support some elastomeric contact with a dynamic surface. In the case of static seals, elastomers span this range although increased squeeze may be necessary.

Eclipse Engineering routinely designs in the range indicated above.

While -65 Fahrenheit is extreme cold, it’s not considered cryogenic. Liquid nitrogen at -320° Fahrenheit (-195°Celsius) requires special hardware and seal material consideration.

To begin, many projects and applications don’t utilize lubricant in dynamic applications. To improve sealability, a better-than-average surface finish is required.

Surface finish often holds lubricity. But without this, a smooth finish reduces friction, improves life, lowers drag, and improves sealability.

Static seals are often required to have leak rates approaching zero; meaning hardware considerations and surface can be even more important. This may mean polishing the groove, which in some applications can be very challenging.

Cryogenic Seal Materials

The next criteria are the seal materials. Elastomeric materials lose their flexibility at these extreme temperatures, so Eclipse relies on polymer-type materials to bridge the gap. When we experience temperatures below -180° Fahrenheit ( -195° Celsius), that’s when it becomes wise to move away from basic PTFE to modified fluoropolymers such as PCTFE, known for operating down to -460 Fahrenheit. Continue reading Designing Cryogenic Seals for High and Low Temperature Sealing

The Role of Seals in the Quest for Medical Cures

The coronavirus has prompted all of us to do everything we can to protect ourselves from catching and spreading the virus. We are all taking important safety measures to maintain a clean and uncontaminated home environment, and limiting our exposure to a potentially hazardous outdoor environment.

picture of coronavirus medicalIn this blog, our partners at Eclipse will be examining the role that seals play throughout a pandemic. The very role of seals is to keep a certain environment in, and certain environment out, similar to how we are living these days.

In Eclipse’s last blog, they wrote about boundary seals in aircraft and how seals allow the aircraft to be pressurized. In the research lab, a different style of boundary seal is required to keep the outside environment out.

Labs all over the world are working toward preventing the spread of coronavirus. Scientists are working with test equipment to find a cure and a vaccine to prevent not just the spread of this virus, but other viruses which we’ve not yet seen.

When we design seals, we must consider keeping something as small as a single cell from entering a test chamber. Last week, Eclipse received a call directly from a customer building a prototype ventilator to be built in volume to help support patients suffering from coronavirus.

The client requested that Eclipse’s engineering and manufacturing team turn an 8-inch (203mm) seal around from concept, design, and finally produced and shipped in less than 4 hours — and they made it happen.

Keep reading to explore the important role that seals play in research equipment as scientists seek to find the cure for coronavirus and beyond. Continue reading The Role of Seals in the Quest for Medical Cures

How HEPA Filters and Boundary Seals Help Protect Us During Pandemics

Boundary seals that help keep a certain environment sealed in while keeping the world out are everywhere.

If you look around your home, you may be surprised to see there are seals surrounding every door — and not just at the bottom. Your oven, microwave, and of course refrigerator door all have seals around them.

All these seals are different, yet they perform the same function. Your microwave is especially interesting, as its primary purpose is to keep microwaves from escaping the chamber that’s cooking your food. Your refrigerator seal has a magnet built into it, which keeps the door sealed shut.

Boundary seals are also found in many cell phones and electronic devices, keeping them water-resistant or water-proof (depending on the manufacturer). And in the industrial world, we have seals to create explosion-proof boxes in hazardous environments. The simple O-ring is found at the end of every cylinder cap to keep fluids in and the environment out.

We all go through great expenses to seal our houses from the outside with sturdy doors, only to find that we need fresh air here and there. Our windows have a series of seals around them keep the heat or the cold outside, but can be opened to allow fresh air when we want it.

In the same way that boundary seals work, the pandemic has many of us thinking about how to keep hazardous germs from entering into our homes. And if we have to fly, we may wonder how fresh the air is in the cabin, and if viruses have an easier time spreading inside of an airplane.

Boundary Seals in Aviation

Let’s begin with general aviation aircraft with pressurized cabins. The door’s seal is in the form of a bladder, which you pump up with the same type of bulb often found on a blood pressure cup.

Doors are especially difficult to seal, as they’re required to open and close. A rubber seal that would compress and seal the door completely would make the door too difficult to open and close.

After the door is closed, the pilot pumps up the bladder to seal the door. As the engines are wound up, the flight deck begins the process of pressurizing the aircraft. A pressure system from the engine maintains the pressure within the cabin around 8000 feet, allowing the pilot to breathe without the use of supplemental oxygen.

While these seals are not dynamic in the true sense of the word, they are constantly changing based on the altitude of the aircraft.

Most of the pressurization seals on our modern jets are static. But every door, including the luggage compartment, has seals that must be pressurized in order for the aircraft to maintain a safe level of oxygen in the cabin.

picture of HEPA filter by GoreDo Jet Planes Blow Clean Air?

Many travelers worry about getting sick on airplanes. With tight quarters and no ability to open a window and get some air, travelers may wonder whether the air from the vents above them is blowing fresh air — or if it’s circulating stale air and germs.

A few months ago, Cliff at Eclipse Seal performed a non-scientific study on a flight by asking the passengers next to him what they thought of the circulated air in modern aircraft today. Cliff was not surprised to find a wide range of answers, varying from someone envisioning a squirrel blower forcing air around the cabin, with others believing 100% of the air comes from the outside.

HEPA Filters on Airplanes

The truth lies somewhere in-between. Turns out, 50% of the air blowing through jet cabins is actually coming from the outside.

That’s one of the reasons why the air that blows through the vents is so cold — the 50% of air that comes from outside is around -30F, which is why stewardesses need to turn the heat on to keep us comfortable.

The rest of the air is recirculated air through a HEPA filter system, or “High Efficiency Particulate Air.”

This is the same air found in surgical operating theaters or clean rooms, with an efficiency that oftentimes exceeds 99% pure. In our modern-day aircraft, this filter helps stop the spread of whatever just came out of that guy’s mouth 5 rows up, cleans cigarette smoke, and even works to stop the spread of infectious viruses through the cabin.

If you’re traveling on one of the silver birds, your best option for the cleanest air is to turn that overhead jet on high and let it blow around your face. This funnel forces air that may be lingering around your nose and mouth aside, providing a fresh stream of cool, clean air.

Cliff even spoke to the pilot or driver of an A320, who has seen the process of cleaning the HEPA Filters. He claimed it was about as nasty as cleaning…well…you get the point.

Another pilot friend of Cliff’s even suggested that if you have to travel during the coronavirus outbreak, you should turn the air on and allow the HEPA filters the opportunity to blow clean, fresh air over your nasal cavities, promoting a safer ride and reducing the probability of infection.

So, bundle up, turn on the jets, and sit back and enjoy the ride. The door seals will keep you breathing, and the HEPA filters could keep you safe.


The original article was written by Cliff Golstein, CEO at Eclipse Seal and can be found on their website.

Gallagher Fluid Seals is an authorized distributor of Eclipse Seal. For more information about how Gallagher and Eclipse can help for your custom application, contact Gallagher.

The Advantages and Disadvantages of the Channel Seal

The Channel Seal (or Cap Seal, as it’s often referred to), was one of the earliest forms of Polymer or Teflon sealing in the seal industry.

The product is easily applied. It didn’t replace the O-ring, but instead offered improved life while reducing drag.

In doing so, hydraulic and pneumatic systems operated cooler and quieter, while improving overall performance of the product.

picture of channel seal

Evolution of the Channel Seal

Before the Channel Seal, the Backup ring was established. The first Backup rings started out as leather, as this material was readily available and could be easily formed into any shape with simple dies to stamp the Backup ring out.

Back up rings provided support for the O-ring, allowing the O-ring to operate at higher pressures, while closing off the Extrusion or “E” gap. This stopped the O-ring from being nibbled in the extrusion gap, therefore extending the life of the O-ring.

Teflon Backup rings were a big improvement, as they would better fill the gap and would stay put (as opposed to leather, which tended to shift in the groove). With the use of two Backup rings, an O-ring was well supported from pressure in both directions.

It was a simple matter to connect the two Backup rings with a thin membrane of Teflon, which removed the O-ring from the sealing surface. This change reduced drag and improved performance, while still maintaining an excellent mechanism for extrusion resistance.

This design was relatively simple to machine out of Teflon, but installation was a challenge, as the Backup rings were full depth. This caused the seal to become distorted during the install process. Today, we almost never see this type of design.

With CNC machining, the ability to nestle, and an O-ring design in a complex Teflon shape, it gave rise to what is referred to today as the Channel Seal, or Cap Seal.

This style seal offers an abundance of advantages over standard back-up rings and the early version of the Channel Seal, which was simply a Backup ring with the membrane of Teflon in-between. Continue reading The Advantages and Disadvantages of the Channel Seal

The Manufacturing Challenges of Tiny Spring Energized Seals

tiny spring energized sealEclipse Engineering has in-house capabilities to manufacture seals up to 55 inches in diameter, and over 100 inches through production partners.

While seals with huge diameters certainly grant their own significant levels of intricacy, here we’ll look at the other end of the spectrum: the micro-sized seals.

We won’t just look at a simple seal ring, but an inherently more complicated and geometrically detailed spring energized seal. As we’ll see, very small diameters make multiple manufacturing aspects more involved and challenging.

The Client’s Issue

A sealing solution in a customer’s epoxy dispensing equipment. They needed an effective seal for the reciprocating rod responsible for the flow-control and metering of the epoxy while being dispensed.

Operating Conditions:

  • Reciprocating Rod Seal
  • Epoxy Dispensing Head
  • Rod Diameter: 1.2mm [0.047”]
  • Stroke Length: 6mm [0.236”]
  • Cycle Rate: 15 per min
  • Media: Epoxy
  • Operating Pressure: 1,500 PSI
  • Temperature: 70° to 150°F

In general terms, most viscous media sealing solutions have three things in common:

  1. A variant of UHMW for the seal jacket,
  2. heavy spring loading, and
  3. multiple point contacts with increased interference.

In most cases, multiple nested V-Springs are incorporated to provide optimal load and energize the compound contact points on the seal. With this formula, we’ve had great success sealing media like epoxy, urethane, silicones and acrylics.

The heavy loading is necessary to effectively wipe the reciprocating rod. This is balanced with the correct material and design geometry to provide long wear life of the seal, which has the potential to be compromised under such loading.

The challenge in this case was to incorporate these same proven principles in a micro-sized seal.

The Eclipse Solution

Continue reading The Manufacturing Challenges of Tiny Spring Energized Seals

The History and Ingenuity of the Buffer Ring: Part 1

Back in the mid 70’s, an engineer named Roy Edlund of Busak & Luyken designed a high-pressure seal that had an uncommon effect of rocking in the groove. This action occurred when pressure was created on the retract side of a cylinder as the rod was being retracted into the cylinder.

The material used for the seal was generally a bronze-filled Teflon, which could resist extrusion and have a long seal life. Because the seal ring was made from a grade of filled Teflon, a small amount of oil would leak under the lip as the cylinder was being extended.

One of the most unique features of this style seal was that as the rod was being retracted back into the cylinder, the buffer ring would rock or rotate slightly to the low pressure side thereby forcing leaked oil back into the retract side of the cylinder under the buffer ring.

This seal is commonly called a Buffer Ring (for reasons we’ll explore in this blog), but this seal helped usher Teflon into most high-pressure hydraulic systems today.

picture of buffer ring

Pre-Buffer Ring Sealing Problems

Manufactures of high-pressure hydraulic systems in equipment, such as back hoes or hydraulic cranes found that their products were having seal failures prior to reaching warranty. This resulted in downtime and large warranty expense to repair these cylinders in the field.

In normal operations, the standard U-Cup made from a variety of Urethanes did an excellent job of creating a “near” zero leak sealing system. The problems would occur as the “bulk” oil temperature rose due to usage, pressure spikes in the system would cause premature failure of the Urethane U-Cup.

It was the pressure spikes that usually wreaked havoc with the U-cup seal design, causing the urethane to break down and eventually crack, creating a leak, and resulting in equipment shut-downs.

The Buffer Ring Solution

The Buffer Ring turned out to be the answer. By adding another sealing element in front of the Urethane U-cup, the life of the U-cup was greatly extended, overall friction in the system was reduced, and the bulk temperature in the hydraulic system was lowered.

All these advantages came by adding a sealing element. The true savings showed up in dramatically improving equipment up time. This also reduced warranty costs of equipment to the OEM.

How Does the Buffer Ring Work?

The answer to this question was initially difficult for many manufacturers to understand. Normally, putting one seal in front of another should cause a pressure trap, sending pressure loads much higher than relief valve settings, which locks up the cylinder.

The secret was in the way the Buffer Ring performed its job.

The seal leaking is very important to its design. If oil didn’t reach the U-Cup, the U-cup would generate heat and begin to wear out prematurely. So, since the Buffer Ring allowed a small amount of fluid to seep under the lip, this fluid lubricated the U-cup and kept its friction to a minimum.

Being elastomeric in nature, the U-cup did an excellent job of wiping the rod nearly completely dry.

But what about the pressure trap?

picture of buffer ring in application

The Buffer Ring and its unique quality allowed fluid back into the system. Testing verified that this would happen anywhere from zero to about 100 PSI.

The U-cup spent most of its life in a well-lubricated, low-pressure / low-temperature environment compared to the original design.

The Buffer Ring also made suppliers of U-Cups extremely happy, as their failed seal had been given new life compared to the holes blown through the back of their urethane product. Continue reading The History and Ingenuity of the Buffer Ring: Part 1

Spring Types and Materials in Sealing Systems

Springs are an integral part of all sealing systems. A simple air cylinder has O-rings to seal in the air, and the O-ring exhibits spring-like qualities to ensure a good seal over a broad temperature range.

But what are the different types of springs and materials in sealing systems? And how do you choose the best for your application?

image of metal spring types

Metal Springs

Metal springs, such as the Cantilever and Canted Coil spring, are used to energize polymers such as Teflon and ultra high molecular weight polyethylene (UHMW) to allow sealing in a wide range of temperatures. Selecting the correct spring material is critical to the life of the seal.

Metal energized seals are often subjected to a wide variety of fluids and temperature ranges, which then requires the correct material choice for the life of the seal in the application.

One of the earliest metal springs was the flat band or marcel expander, often made from common materials like 300 series Stainless Steel or heat treated 17-7 Stainless Steel.

These materials are often chosen for their tensile strength. But due to the cost to manufacture and the high volumes of spring required, these two expanders were often relegated to industrial or aerospace hydraulic systems.

If system fluids were not compatible with Stainless Steel, customers generally went to a different sealing system to avoid the high cost of short runs in these styles of energizers.

O-Rings cover a wide range of temperatures, and fluids, but generally not both. If there are multiple fluids involved, O-Rings often fail to provide compatibility over a range of fluids.

The use of Cantilever, Canted Coil or Helical coiled spring allowed for long runs and lower costs. The most common spring material is Stainless Steel, but these styles of spring lend themselves to materials that have a wide range of chemical and temperature range while maintaining tensile strength.

Alternative Spring Materials

Some of the more common alternative materials are Hastelloy and Elgiloy. While 17-7 is available, it’s seldom used because Elgiloy (while more expensive per pound) is often run at a higher volume, bringing the overall cost down making 17-7 less attractive due to cost.

Another style metal spring for polymers is the Garter spring. Garter springs are normally run on a per job basis, but because it’s made from wire, it can easily be wound from any material like Elgiloy or Stainless.

Garter springs are often used in rubber style lip seals, but we often find them coupled with polymer-style seals.

Mechanical Seals

Mechanical face seals typically marry a material with the fluids the seal will be running in. Mechanical seals have the overall body and internal springs made from specific materials capable of handling variations in temperature and fluids.

PEEK in Seals

Polymers are thought of as seal materials, but PEEK has been used as a spring in polymer-style seals. PEEK can be wound into helical style springs, and also formed into cantilever springs. As a Helical style, it can be wound into a diameter to energize Teflon or rubber lip seals.

If you consider radiation service, a PEEK spring makes an excellent choice keeping metals out of the seal.

How to Choose the Right Spring Material

While there are a variety of metals, often economics determine the practicality of specialty metals.

A consideration is reviewing the hardware used in the application as to what spring material is acceptable in an application. We often review what the customer is using in the rest of the service for determining a spring material.

Temperature is often a key factor in determining materials for spring. Elgiloy tends to do an excellent job in maintaining tensile strength at elevated temperatures.


The original article can be found on Eclipse Engineering’s website and was written by Cliff Goldstein.

Gallagher Fluid Seals is an authorized distributor of Eclipse engineering. For more information about choosing the right spring material for your application, contact our engineering department today.

The Many Uses of Polytetrafluoroethylene Seals (Teflon)

Better known as Teflon in the industry, Polytetrafluoroethylene is widely used in practically every industry on and off the planet (and even beneath its surface!)

Medical Uses

white ptfe o-ring-teflonThis material’s primary claim to fame is its resistance to most chemicals. It inherently has an extremely low coefficient of friction, it’s easily machined from rods, tubes, or compression-molded shapes.

It’s one of the few polymers that are approved for medical implants due to its inertness to bodily fluids — the immune system principally ignores its presence in the body.

Moving away from the body, you’ll find PTFE or Teflon products in medical devices such as heart lung machines, rotary tools for cutting, and sealing devices for maintaining fluid streams for irrigation and pumping. Tiny fragments that may come loose during usage are not harmful to the body, and simply pass through the system.

Pharmaceutical Uses

In the pharmaceutical industry, Teflon is used in the processing of drugs for equipment used to manufacture such as mixers, presses, and bushings. Teflon is found in a variety of applications, as any debris from the seal will pass through the body without consequence.

When considering press machinery (which are often water driven to ensure any leakage will not spoil the product), Teflon seals are often used to help reduce friction — especially in repetitive presses where a build-up of heat would be detrimental to the seal and the product.

Food & Beverage Uses

Mixers are another area to ensure keeping grease and other contaminants from the motor to not descend into the product from the mixer shaft.

Another area is pressure vessels where two shells are clamped together to ensure product remains sealed inside. Failure of these seals usually results in loss of product.

Non-metal bearings that don’t requiring grease in rotary motion are an excellent place for Teflon style bushings. These bushings provide long life with very low friction while not contaminating the product. Shaft wear from the bushing may be eliminated with the use of Teflon.

Types of PTFE (Teflon) Seals

Seals in the medical field can be as simple as a static O-Ring, or a mechanical face seal which is costly and requires special consideration during installation. Most dynamic applications can be resolved with spring-energized style seals, which often have very low friction and can be clean in place (CIP) if required.

There are different styles of springs, such as cantilever or canted coil that provide varying loads. The cantilever-style spring-energized seal provides a linear load based on deflection providing a high level of seal-ability. It can be silicone-filled to provide CIP for ease of washing, and there are a variety of materials that are FDA compliant and that work well in both viscous and pure aqueous fluids.

Canted coil spring-energized seals provide a unique feature of controlling the load the spring exhibits on the sealing element. This allows for control of a device being manipulated during a procedure.

The polymer properties give the user materials with the lowest possible friction, while still sealing in an application. The load from a canted coil spring allows the user to feel a tool in a catheter while passing the catheter through a tube, and still retaining a seal.

As you can see, PTFE has a variety of uses across a broad range of industries. GFS’ partner, Eclipse Engineering, manufactures PTFE and can help provide solutions to customers facing both simple fixes or complex problems.

Contact us today to see if PTFE might be the right choice for your application.


For custom engineered parts, or for more information about a variety of PTFE seals we can provide, contact Gallagher Fluid Seals today.

The original article was written by Eclipse Engineering and can be found on their website.

Angled Spring Grooves for Custom Spring Energized Ball Seats

A ball valve is a simple and robust valve used in applications and industries across the spectrum. It consists of a ball with a hole through the center that can be rotated 90°.

custom spring energized ball seat

The hole is either aligned with flow and open, or perpendicular to flow and closed. The straightforward, quarter-turn action is fast and simple to operate, and the position of the handle provides a clear indicator of whether the valve is open or closed.

Most ball valves are typically used as a shut-off valve. Many households likely use ball valves at some point in the water supply plumbing.

Not relegated to common plumbing, many industries use ball valves for critical control applications including aerospace and cryogenics. Their reliable operation and high-pressure handling ability make them an attractive solution for many specialty operations.

Seals Inside a Ball Valve

The seals inside the ball valve play an important role in their performance and reliability. There are two main seals in a common ball valve, which are referred to as seats.

The seats are typically machined or molded to match the diameter of the ball and are mechanically compressed against the ball face. Seat material varies by application needs, but virgin PTFE is frequently used for this application.

The Client’s Issue

The customer wanted a very specialized ball seat: utilizing a spring energizer in the seat. While easy to suggest, this would create a significant challenge in how the seal is manufactured.

The customer was looking for a sealing solution for a ball valve in their industrial gas processing plant. The ball valve would serve as a critical shut-off point in the system. The valve would be actuated by an electric motor, and could therefore be operated remotely.

The customer was looking for an improvement in the overall wear life of the ball seats, while still providing consistent and predictable actuation torque. Being motor activated, the torque required to move the ball open or closed was limited—so the friction generated by the ball seats would need to be carefully controlled.

Operating Conditions:

  • Ball Valve Seat
  • Ball Diameter: Ø2.500”
  • Media: Petroleum Processing Gases
  • Pressure: 100 PSI
  • Temperature: -40° to 175°F

The Challenge

Continue reading Angled Spring Grooves for Custom Spring Energized Ball Seats