Category Archives: gasketing

Gaskets for High-Density Polyethylene Flanges

Recent gasket failures in flanged joints of High Density Polyethylene (HDPE) piping.

Problem

HDPE piping joints are typically thermal fusion welded joints, but flanges may also be used. When flanges are used, an HDPE flange adapter with a metal backing ring is fused to HDPE piping, as shown in Figure 1. The HDPE flange adapters are used to connect to other flanged fittings, such as valves, elbows, tees, etc., with gaskets inserted between the flanged fittings.

Incident Description

Picture of Eroded GasketIn 2018, two HDPE flange adapter gaskets on two different valves that were part of an underground fire suppression system at a Department of Energy (DOE) nuclear facility in Amarillo, TX failed, causing several weeks of unplanned interruptions to nuclear facility operations. Fire suppression water was isolated to two nuclear facilities, requiring nuclear operations to be paused and fire watches to be established. Both couplings were installed by the same contractor and had been in service for approximately eight years. Both flanges were correctly torqued to 160 foot-pounds with no indication of the necessary re-torque. The initial failure of the gasket caused a low flow, high-pressure leak that was not detected for some time. Picture of Flange Face ErosionWith the system pressure operating at approximately 150 pounds per square inch (psi), the orifice created by the failure of the gasket(s) between the two flanged faces created a water jet, which eroded the metal valve flange and bolts.

Because HDPE will relax after the flange bolts are torqued, a re-torque after 24 hours is required. Even after the bolts are re-torqued, the face stresses drop to 400–600 psi. The lower face stress reduces the friction for maintaining the gasket in between the flange faces. The challenge is finding a gasket that can handle pressures that may exceed 200 psi, gauge (psig), but also seal well at relatively low stresses.

Due to the many inquiries from customers and engineering firms for gasket applications involving HDPE piping, Garlock, a gasket manufacturer, published a memo in January 2017 recommending using either GYLON® Style 3545 or MULTI-SWELL™ Styles 3760/3760U as the best options for HDPE flanges, even though the available compressive loads are lower than recommended. The reinforced gasket material of the GYLON and MULTI-SWELL has proven to prevent the internal water pressure from damaging the gasket under low-compression loads.

Other gasket manufacturers may have similar gaskets that will work for this application. It is important for the Design Engineer to work with the gasket manufacturer to properly specify the correct gasket.

Recommendations to HPDE Piping and Flanged Joints

When using HPDE piping with flanged joints, ensure that the flange bolts are re-torqued at least 24 hours after gasket installation.

When evaluating gasket material, be sure to include any surge pressure that could be caused by opening valve and starting pumps. Also, include any additional design/safety factors in your gasket calculation. And, directly work with the gasket manufacturer in making a selection.


If you have questions about HPDE piping and flanged joints or any other engineering applications, contact Gallagher Fluid Seals.

Original article written by Brian Rhodes, Department of Energy.

Low Temp Gaskets – How Low Can You Go?

Rare and Ultra-Pure Resources Present Unique Challenge to Finding Appropriate Low Temp Gasket

Modern technology often requires rare or ultra-pure materials that can only be handled or obtained within extreme environmental conditions. These same conditions present unique and hazardous difficulties when transporting or utilizing these resources. Resources such as liquid oxygen, nitrogen, or argon; all of which are classified as “industrial gases” are handled well below the normal temperature ranges that every-day liquids exist; ranging as low as -195.8°C (-320.4°F). This often makes it a challenging task to find a low temp gasket to fit the specifications for the application.

As an example, let’s look at argon; an important gas used in Welding, Neon Lights, 3D Printing, and Metal Production, just to name a few. It is far more economical to house and transport argon in its liquid state. However, it must be held at an astonishingly low -185.9°C. Fitting the pipes together and maintaining a seal in a cryogenically engineered system that the liquid argon is housed presents unique difficulties. Argon gas is colorless, odorless, tasteless, and can irritate the skin and the eyes on contact. In its liquid form it can cause frostbite.

There are important considerations that should be taken into account when installing gaskets for dangerous extreme low temp materials.

Proper Gasket Installation

Many gasket materials can become brittle, crack, shrink, and blow out when exposed to extreme cold – not something you want to happen at any time, let alone with a liquid that can freeze you into a meatsickle. So, proper installation is also key. During installation, it is important that all parts are dry, the installation is done at ambient temperature, and then re-adjusted with changes in temperature.

Cryogenics

Any mechanical seal that is sealing a product with a temperature below 0 degrees Celsius is given the name “Cryogenic”. Liquefied gases (LNG), such as liquid nitrogen and liquid helium, are used in many cryogenic applications, as well as hydrocarbons with low freezing points, refrigerants and coolants.

When selecting a low temp gasket or sealing material to be used in cryogenic service, it is important that the material can withstand cryogenic temperatures.

Low temperature applications are found across many industries, these include:

  • Chemical
  • Food
  • Pharmaceutical
  • Refrigeration
  • Petroleum
  • Automotive

Garlock GYLON® and KLINGER SLS/HL

3500 and klinger flexible graphite

Good gasketing materials that can withstand the frigid cold and are pliable in the requirement to maintain the seal would be the Garlock GYLON family of gaskets (PTFE, capable of -450°F (-268°C)) or the Klinger SLS/HL, which is made of flexible graphite and can withstand -400°F (-240°C)

Conclusion

As with all gasket applications, environmental conditions should be considered in conjunction with the functional requirements of the device. Though there are limited options to solve extreme low temp gasketing challenges, Gylon and Klinger can be a good fit for your application.


Portions of the original article were written by Michael Pawlowski and Sylvia Flegg of Triangle Fluid Controls Ltd. The article can be found on Empowering Pumps website here.

For more information about low temperature gaskets and which might be a fit for your application, contact Gallagher Seals engineering department.

Enhanced Surface Profiles for Gaskets

How this feature can improve performance and efficiency with gaskets

Gaskets have always been part of industrial production. However, gaskets have not always been forgiving, easy to use or simple to remove. What if the sealing products were designed to optimize the work put into them? What if the design had a level of intelligence built in? What if the design could make up for equipment damage? When used properly, enhanced surface profiles for gaskets can reduce leaks, spills and other releases that can damage the environment, put people at risk, result in fines and lead to costly downtime.

Using surface profiling to reduce area and increase stress is found in everyday life, from the soles of running shoes to the treads on vehicle tires. Reducing the contact area while maintaining compressive force results in increased stress. In the case of gaskets, traction or friction between a gasket and the flange faces is critical to holding internal pressure. If the downward force created by the fasteners in a flange is diluted or spread over a larger area, the overall stress is reduced.

Compressibility

Adding raised features to the surface of a gasket to reduce contact area and increase stress also tends to impact compressibility. Compressibility represents the ability of the gasket to conform to the surfaces it is being used to seal. Flange surfaces usually show signs of wear, pitting, scratches or other defects. It is cost-prohibitive to make two mating flange faces smooth and flat enough to seal without a gasket. The more compressible a gasket is, the better chance the user has of attaining an effective seal.

picture showing different gasket views
Image 1. (clockwise left to right) Traditional material sees heavier load around the gasket bolts and lighter load farther from the bolts. Image 2. Load distributed more evenly. Image 3. More stress toward the bolts. Image 4. Stress spread evenly around the gasket. (Images courtesy of Garlock)

Pressure Resistance

Compressibility also impacts the amount of pressure exposure on the gasket. When a flange assembly is pressurized, the internal media pushes outward on the inner diameter of the gasket. The thinner a gasket becomes, the less outward force it sees from internal pressure. This is referred to as improved “blowout resistance.” Unfortunately, one common error made when a gasket blows out is to replace it with a thicker gasket. This puts more gasket surface in the pipe or vessel for the internal pressure to act on.

Sealability

To create an effective seal, there are two functions the gasket must accomplish.

First, it needs to conform to the flange face to prevent the media from passing between itself and the flange faces. This is where the compressibility is important. Continue reading Enhanced Surface Profiles for Gaskets

The Lifespan of a Gasket

The Dreaded Gasket Blowout Call

Have you ever received the dreaded 2 a.m. call from plant staff saying that things are at a standstill – production is down?

You arrive at the plant, walk through the parking lot, coffee in hand, and head to the locker room. When you come out on to the plant floor, there are several people staring at you with a look of panic on their faces as steam or process chemical sprays from a pipe flange.

Prognosis……gasket blowout.

You think to yourself “didn’t we just replace that gasket?”, or perhaps “we should have replaced it during the last shutdown but chose not to because of time constraints or cost cutting.

If this scenario is new to you, you are lucky and you can go back to sleep… the 2 a.m. call was a wrong number. If it’s not new to you, this means you are most likely a Plant Supervisor, Maintenance Manager or Plant Personnel in some capacity.

Roll up your sleeves, grab your torque wrench and let’s get to work!

Gasket Lifespan

Picture of NSF Compliant GasketsIf I had a nickel for every time someone asked me, “How long will my gasket last?” I would be a rich man. As you can probably guess, “How long will my gasket last?” is a loaded question to which the practical, factual, and political answer is… an Application Engineer’s nightmare!

A gasket may last 5 years, or it could last 20 years. I cannot give you an exact date or lifespan of a gasket; however I can give you some insight into factors that will give your gasket the best chance at a long and prosperous life between the flanges.

Continue reading The Lifespan of a Gasket

Fried Snack Foods and GYLON® Style 3504 Gasket

Fried Snack Foods and GYLON® Style 3504 Gasket

The GYLON Style 3504 gasket is made of PTFE with aluminosilicate microspheres. It is designed for use in moderate concentrations of acids, caustics, hydrocarbons, refrigerants, and more.

It provides a tight seal, improved performance over conventional PTFE, reduced product loss and emissions, reduced creep relaxtion, excellent bolt torque retention, it doesn’t burn, will not support bacterial growth, plus many more benefits.

INDUSTRY

Food Processing – Fried Snack Foods

CUSTOMER

A major diversified food & beverage manufacturer, with facilities located in all regions across the globe.

BACKGROUND

The customer had persistent problems when sealing hot oil applications on its bulk snack food fryers across several production sites. Build-up of polymerised vegetable oil on the flanges caused unsightly mess, maintenance complications, financial implications, and posed a significant fire risk.

CHALLENGES FACED

As well as ensuring that the sealing material was compliant to FDA and EN1935 standards, the challenge was to ensure that the gaskets would perform well under the difficult conditions presented by the high oil temperatures. Additionally, because the production line was also subject to regular and aggressive cleaning cycles, the gasket material was required to be compatible with other aggressive chemicals across a broad pH range.

Continue reading Fried Snack Foods and GYLON® Style 3504 Gasket

Pipe Gaskets for Diverse Flange Materials

Looking to consolidate your inventory into as few materials or parts as possible?  Would eliminating the installation of incorrect gasketing material interest you?  GORE® Universal Pipe Gaskets may be the answer.

GORE Universal Pipe Gaskets (UPG)GORE® Universal Pipe Gaskets (Style 800) provide a reliable seal for steel, glass-lined steel and fiber reinforced plastic (FRP) flanges, in the full spectrum of strong acid, alkali, and solvent process media, including the most challenging thermal cycling and elevated temperature applications. This single gasket solution can reduce the process safety and production downtime risks caused by the use of an incorrect gasket material. The highly conformable 100% ePTFE also reliably seals irregular surfaces.

Continue reading Pipe Gaskets for Diverse Flange Materials

Case Study: Eliminating Epoxy Use on Flanges

GYLON EPIX™ is a family of gaskets that effectively seals a broader range of applications and is more forgiving during the installation process.  It allows the end user to save valuable turn-around time, reduce re-work, and lower costs, helping them to finish ahead of schedule and under budget.

GYLON EPIX™ features a hexagonal surface profile that provides the torque retention and blowout resistance of a thin gasket and the conformability of a thicker gasket.  GYLON EPIX™ Style 3504 EPX is a high performance, aluminosilicate microsphere filled PTFE sheet material designed for use in moderate concentrations of acids, and caustics, as well as hydrocarbons, refrigerants, and more.

EPIX™ - Phosphate Plant

INDUSTRY

Chemical

CUSTOMER

Phosphate Processor

Continue reading Case Study: Eliminating Epoxy Use on Flanges

GYLON EPIX™ Reduces Gasket Installation Issues

GYLON EPIX™ is a newly developed family of PTFE gaskets. It is manufactured using a patented, profiled surface based on our proven Fawn, Off-White, and Blue GYLON® to create highly conformable materials for optimum sealing performance.

Watch the video below to learn more about GYLON EPIX™, and how it’s patented
hexagonal surface profile can help you reduce gasket installation issues.

GYLON EPIX™ will provide superior functional performance by combining the traditional attributes of GYLON® with an innovative surface design. It offers a broader range of applications than traditional PTFE gaskets that are used in worn and pitted flanges. In addition, this evolutionary material delivers the tight sealing and load retention properties of 1/16” (1.6mm) and the conformability of 1/8” (3.2mm). The hexagonal profile provides GYLON EPIX™ - 3504 EPXimproved compressibility and recovery. The profiled surface reduces the contact area during initial compression to concentrate the compressive force of the flange for improved sealability.

Designed for increased compressibility, GYLON EPIX™ improves performance in misaligned flanges. The consolidation of two thicknesses to one reduces the need to inventory multiple thicknesses. Garlock is dedicated to providing real sealing solutions that meet real world sealing needs. With an improved design, color-coded materials, and single thickness, GYLON EPIX™ makes sealing easier.

For additional information about specific GYLON EPIX™ products:

GYLON EPIX™ Style 3500 EPX

GYLON EPIX™ Style 3504 EPX

GYLON EPIX™ Style 3510 EPX

Case Study: GYLON EPIX™ 3504 EPX

GYLON EPIX™ - 3504 EPXGYLON EPIX™ is a family of gaskets that effectively seals a broader range of applications and is more forgiving during the installation process.  It allows the end user to save valuable turn-around time, reduce re-work, and lower costs, helping them to finish ahead of schedule and under budget.

GYLON EPIX™ features a hexagonal surface profile that provides the torque retention and blowout resistance of a thin gasket and the conformability of a thicker gasket.  GYLON EPIX™ Style 3504 EPX is a high performance, aluminosilicate microsphere filled PTFE sheet material designed for use in moderate concentrations of acids, and caustics, as well as hydrocarbons, refrigerants, and more.


INDUSTRY

Material Processor

CUSTOMER

Cement Manufacturer

BACKGROUND

The customer experienced gasket leaks in their piping system.  This caused lost time due to repairs and clean-up efforts.

CHALLENGES FACED

Several issues that plagued the system – abrasive media stream caused gasket and flange erosion, and low strength bolts prevented the customer from using higher performance gasketing materials that require higher assembly stresses to properly seal.

GYLON EPIX™ 3504 EPX

OPERATING CONDITIONS

  • Media: Dry Cement
  • Temperature: 185°F (85°C)
  • Pressure: 102 psig (7 bar)
  • Class 150 Raised Face Flanges
  • Grade 2 Bolts (low strengths, 57ksi yield strength)

SOLUTION AND BENEFITS

The customer’s desire to have a sealing solution that could work with flanges in their current condition, as well as the lower strength bolt led to the evaluation of the GYLON EPIX™ 3504 EPX in a 6″ 150# raised face flange.  The 3504 EPX gasket effectively seals the damaged flange faces with the lower strength SAE Grade 2 bolts.


Gallagher is your source for all of your Garlock sealing needs.  If you have further questions regarding the GYLON EPIX™ 3504 EPX, or any other Garlock products, please do not hesitate to contact us. Our engineering department is always ready to help you design a sealing solution to your toughest application!

Introducing Garlock GYLON EPIX™

In a world where we are bombarded with the belief that “more is better”, sealing science contradicts that theory with facts that show “thinner is better” when it comes to gaskets, as they provide improved load retention, pressure resistance and sealability. Yet thicker gaskets have their place for uneven, worn or damaged sealing surfaces. So how does a person make the right choice? What if there was a product that could do both?

Now there is…

GYLON EPIX™ is a family of gaskets that effectively seals a broader range of applications and is more forgiving during the installation process. GYLON EPIX™ allows the end user to save valuable turnaround time, reduce re-work, and lower costs, helping them to finish ahead of schedule and under budget.

Garlock GYLON EPIX™The innovative GYLON EPIX™, provides superior functional performance by combining the traditional attributes of GYLON® with an innovative surface design. It offers a broader range of applications than traditional PTFE gaskets used in worn and pitted flanges. In addition, GYLON EPIX™ delivers the sealing and load retention properties of 1/16” and the conformability of 1/8”. The hexagonal profile provides improved compressibility and recovery. The profiled surface reduces the contact area during initial compression to concentrate the compressive force of the flange for improved sealability.

Continue reading Introducing Garlock GYLON EPIX™