Category Archives: gasket

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.

A Case Study: GYLON® 3504 and 3545 Gaskets

Wine Manufacturing with GYLON®

Gylon 3504

Picture of Garlock 3545The GYLON® Style 3504 gasket is made of PTFE with aluminosilicate microspheres. It is designed for use in many acids, some caustics, hydrocarbons, refrigerants, and more.

Gylon 3545

The Garlock 3545 style is a highly compressible microcellular PTFE with a rigid PTFE core for improved handlability. Garlock 3545, made with Gylon material, is designed to compress and conform to irregular or damaged surfaces, making it suitable for flanges that generate lower compressive stresses, such and glass-lined flanges and equipment.

INDUSTRY

Food & Beverage – Wine Production

CUSTOMER

An award-winning, family owned & operated winery in the heart of a major US wine-growing region.

BACKGROUND

The customer crushes, presses, ferments, bottles, and labels all of their wines at their winery, but having traditionally utilized EPDM gaskets, they faced ongoing issues with seal reliability. This was occurring during various stages of the winemaking process, but especially so during the sterilization procedures between each batch, with subsequent leaks creating issues in production reliability, housekeeping, and potential contamination.

CHALLENGES FACED

Business was growing rapidly so new equipment had been installed, but at the same time the number of maintenance windows was reducing. Therefore the customer was looking for a more reliable and sanitary product to improve efficiency and help to protect the sensitive product. As well as the need to remain absolutely compliant with industry standards, the customer also placed utmost importance on prevention of any adulteration of their award-winning wine. As well as working around limited windows of opportunity for production trials the critical and expert opinion of wine tasters was therefore essential to ensure full approval of any component change in the process.

Continue reading A Case Study: GYLON® 3504 and 3545 Gaskets

Contain Aggressive Media, Protect Glass-Lined-Steel Equipment, Reduce Emissions

Gasket Tape Series 1000

Sealing Challenges

Glass-lined steel equipment is used by chemical processers to deal with aggressive media under demanding conditions. Yet the inherent demands of such systems – high temperatures, alternating system pressures, limited gasket loads and deviation of sealing surfaces – can make it challenging to maintain a tight, lasting seal.

While the Polytetrafluoroethylene (PTFE) material itself offers good chemical resistance, it does not readily conform to flange surface deviations, nor does it resist creep particularly well under low gasket loads. Incorporating compressible materials or fillers into common envelope gaskets or filled PTFE gaskets, offers only a partial solution.

Sealing challenges are even greater when gaskets for large flanges (≥DN 600/ASME 24″) are fabricated offsite. This often results in long lead times, as well as shipping, handling and inventory challenges. These, along with time-consuming and complex installation procedures, can complicate turnarounds or delay start-ups.

The Consequences Of Failure

Any of the mentioned approaches, especially if they involve
inconsistent quality across different gasket brands or product
lines, may lead to premature gasket failure, with consequences
that range from problematic to catastrophic, including:

  • Leakage/emissions
  • Equipment corrosion/damage
  • Production downtime
  • Cost increase
  • Risks to personnel safety

Gore Gasket Tape Series 1000 Addresses All the Challenges of Reliably Sealing Large Glass-Lined-Steel Flanges.

cross section of gore gasket tape 1000Made of 100 % expanded PTFE (ePTFE), this highly conformable gasket tape is chemically inert, and highly resistant to creep, cold flow and clamp-force loss. Its proprietary barrier core maintains an extra tight seal even at low loads.

Endorsed by De Dietrich, a leading manufacturer of glass-lined steel equipment, Series 1000 is optimized for processes utilizing highly aggressive media, as in chemical processing (e.g. specialty chemicals, agricultural products, polymers), mining and minerals. Series 1000 is designed for use in large (≥DN 600/ASME 24″) or non-standard flanges typical of columns, mixer vessels, reactors, storage and receiver tanks.

A Higher-Performance Sealing Solution

leakage rate on a 0.5mm deviationUnique barrier core technology

  • Barrier core engineered to amplify the available load.
  • Seals more than 10 times tighter than other types of ePTFE gasket tape.

Outstanding conformability to deviations

  •  Seals deviations even at low gasket stress.
  • Easily passes the bubble test, for trouble-free mechanical completion (MC) or start-up.

Optimal form for easy handling

  • Gasket can be customized on-site.
  • No fabrication lead-time required.
  • Convenient spool format simplifies and speeds handling & transport.
  • Adhesive backing enables easy installation.
  • Faster, less complicated shimming tape technique for larger deviations.
  • Reduces inventory costs.

Reliable and long-term seal

  • Barrier core creates a tight seal that impedes even highlypermeating media.
  • Provides chemical protection across the full flange width (100% ePTFE).
  • Gasket tape is engineered to resist creep and clamp force loss.
  • Allows full use of specification range of the glass-lined steel equipment.
  • Enables longer maintenance cycles, as demanded by leading chemical producers.

The Gore Sealant Technologies Quality Management System is certified in accordance with ISO 9001.


Original content can be found on Gore’s website.

Gallagher Fluid Seals is an authorized distributor of Gore Tape. For more information about how this solution can help you, contact our engineering department at 1-800-822-4063.

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

Water Regulations and NSF 61 Compliant Elastomers

Replacing Aging Water Infrastructure With NSF Compliant Materials

There are over 155,000 public water systems in the United States and more than 286 million Americans who rely on community water systems daily.  Since most of the infrastructure was built between the early 1900’s and 1960 using outdated technology/products and capabilities, nearly everything is approaching the natural end of it’s lifespan.

Some estimates put the repairs and replacement of thePicture of NSF Compliant Gaskets infrastructure between $250B and $500B over the next 20-30 years. Several applications will need to be updated or fully replaced for the safety of consumers and quality of delivery, including:

  • Joining and sealing materials
  • Mechanical devices
  • Pipes or related products
  • Process media
  • Plumbing devices
  • Non-metallic potable water materials
  • Hydrants
  • and Public drinking water distribution (tanks and reservoirs, maters, individual components)

Joining and Sealing Materials

When these systems were being constructed and assembled decades ago, there were limited regulations and requirements that needed to be met. Gaskets, at least the traditional ones, were often made in two different ways: (1) Red Rubber (ASTM D1330 Grade 1 &2) with compressed non-asbestos or (2) cloth-inserted rubber with compressed asbestos.

However, today’s acceptable gasket requirements for the potable water industry differ greatly from those in the past. Gaskets have strict guidelines to abide by and must be:

  • Chemically resistant
  • NSF compliant
  • Food grade compliant
  • Electrically isolating

Because of the need for health and safety, the National Sanitation Foundation (NSF) was created in order to establish minimum requirements for the control of potential adverse human health effects from products that contact drinking water. In addition to gaskets, the NSF covers a variety of products and parts relevant to the water industry, including: pipes, hoses, fittings, cements, coatings, gaskets, adhesives, lubricants, media, water meters, valves, filters, faucets, fountains, and more.

So you might ask – why does the NSF require different materials and regulations for gaskets compared to years ago?

First things first – leaks are a major issue with the aging infrastructure. Improperly placed gaskets & seals or faulty products can cause leaks. This in turn could pose health risks to people drinking potable water or using products processed with potable water.

Additionally, the treatment process and chemicals utilized are Picture of NSF 61 Compliant Sealsdifferent from previous “standard” products. For example, research and testing over many years has concluded that traditional gaskets, which were used many years ago, could pose a safety threat to those drinking water processed with specific materials. This led to updated regulations for NSF 61’s drinking water system components.

Lastly, engineered sealing solutions are more important than ever. There’s a wide variety of custom engineered water systems throughout the U.S. – climate, geographic terrain, and the needs of the community are all reasons for why water infrastructure is so unique. Because of this, custom gaskets, seals, and other products are needed to supplement those systems.

Luckily there are many companies dedicated to providing the highest quality NSF 61 products. These trusted brands have proven materials to count-on when replacing or repairing water infrastructure:

Garlock’s NSF 61 Family of products

Parker’s NSF compliant products

Freudenberg’s new generation of NSF products

For more information on how Gallagher Fluid Seals’s engineers can help you with a custom solution, call us at 800.822.4063

FDA Standards Key to Proper Gasket Selection

Food and beverage producers rely on a wide array of equipment to ensure their products are safe and free of contamination. Sealing devices such as gaskets are key components in this equipment, yet do not receive the attention they warrant given the critical importance of their function.

Gasket Selection - PTFE
PTFE (Polytetrafluoroethylene) Molecule

PTFE-based and elastomeric seals have for decades been the products of choice for food and beverage applications. The two most commonly referenced Food and Drug Administration (FDA) standards for sealing products are found in the Code of Federal Regulations under Title 21 (Food and Drugs), part 177 (Indirect Food Additives: Polymers). Section 177.1550 focuses on perfluorocarbons such as PTFE- based products, and Section 177.2600 deals with rubber articles intended for repeated use.

These two standards specify which ingredients used in the production of sealing products are acceptable for applications where contact with food products can occur, as well as how much of the approved ingredients can be released from the polymer/elastomer when extracted with specific media — i.e. water, hexane, etc. — under specified testing conditions.

Continue reading FDA Standards Key to Proper Gasket Selection

S.T.A.M.P. Gasket Selection Criteria

GasketWe recently updated our Gasketing webpages to provide our customers with much more robust product information, to help you along your journey of finding the right gasket for your application.  Visit our Non-Asbestos, Metal, Elastomeric, or ePTFE Gasket Tape pages to learn more.


S.T.A.M.P.

When you’re specifying a gasket for even the simplest application, it is important that the gasket supplier know all the operating parameters.

There are five major pieces of information needed to select the appropriate gasket, known by the acronym S.T.A.M.P.:

Gasket - Raised Face FlangeSize:

While gaskets are most often used in standard ANSI flange connections, non-standard flanges can also be found throughout a plant.  In dealing with non-standard flanges, it is VERY important to obtain as much detail as possible about the contact dimensions (the portion of the gasket actually being compressed) and the fasteners or bolts being used (size, grade, quantity). This information is used to calculate the contact area and available assembly stress – a key factor in the selection process, as an improperly loaded gasket could result in premature equipment failure.

Continue reading S.T.A.M.P. Gasket Selection Criteria