Tag Archives: gaskets

Gasket Types and Their Applications

Understanding the Difference Between Gasket Types

picture of gasketsAs our friends at Dichtomatik like to say, “where there are pumps and valves, there are also gaskets.”  Gaskets are critical components in fluid conveyance systems. There is a wide variety of types and materials that they can be made from.  Many of the most commonly-asked questions revolve around which gaskets are right for which situations for a variety of industries including but not exclusive to: food & beverage, oil & gas, construction, agriculture, energy & power generation, and chemical processing.

While far from an inclusive list, GFS wanted to quickly touch on some of the most common gasket types and materials often asked about.

A Quick Guide to Gasket Types:

Spiral Wound Gasket

Spiral-wound gaskets utilize two sealing elements – the winding and the filler – the winding behaves like an energized spring against the flange surfaces while the filler seals the imperfections between the two surfaces. An outside ring is standard in flange applications to center the gasket between the bolts and help prevent blowout.  Stainless steel inner rings are often added to prevent the windings from buckling inward potentially contaminating the media. They combine high strength with reliable sealing capacity. They function as well in low pressure and temperature applications as they do in more extreme environments, but are more expensive to produce compared to compressed fiber and elastomeric gaskets.

Sheet Gasket

The simplest type of gasket, this is made from common rubber elastomers or compressed fiber and can be easily cut into virtually any size with any configuration. While often suited for low pressure environments, sheet gaskets are an ideal solution for industry standard applications like creating a reliable seal between flanges and fittings for fluid movement.

Elastomer Sheet Gasket

Most rubbers are relatively inexpensive and can be easily cut into shapes on demand. Our friends at Dichtomatik, a subsidiary of Freudenberg Sealing Technologies, maintain a variety of sheet materials to meet customer requirements – including SBR, Neoprene, EPDM, NBR, and FKM.

Aramid Fiber Sheet Gasket

Aramid fibers are a particularly strong and heat-resistant form of synthetic fiber which can have exceptional strength when tightly-woven while being low-weight. They also are highly resistant to impact, abrasion, or chemical erosion.  However, they are also absorptive and have poor compression properties. A broad variety of compressed fiber sheets are available; they are versatile and inexpensive. They can generally handle maximum temperatures and pressures over 700°F and 1,000 PSI. 

picture of different gasketsElastomeric Molded Gasket

Also known as press-in place gaskets, these all-elastomer gaskets are custom-shaped and are designed for applications where there is a groove that positions the gasket between components to optimize the sealing performance in the groove. They are easy to install, require no adhesive, and are self-retaining and adaptable.

Custom-Made Gaskets

For all other applications, there are custom-made gaskets.  Gallagher Fluid Seals can help advise on material, design, and other gasket questions. Our suppliers place us in a position to provide a variety of materials, including flexible graphite, PTFE, FKM, FFKM, and more.


The original article was featured on Dichtomatik’s website and can be found here.

Gallagher Fluid Seals is a partner of Dichtomatik. For more information about finding the right type of gasket, contact our engineering department today.

Tips for Gasket Storage and Maximizing Life

So you spend hundreds or even thousands of dollars every year on sealing solutions, like gaskets. But did you know that the way you store your gaskets could affect the effectiveness or life span of your gaskets? In this blog, we offer some tips for gasket storage and shelf life which, if followed, can help ensure that your gaskets are always ready for service.

Gasket Storage and Shelf Life: General Storage Principles

Rubber gaskets should always be stored in a cool location which is free from excessive humidity, direct sunlight, and the presence of chemical vapours or fumes. The storage location should ideally be indoors and free from exposure to the elements or inclement weather. If the storage guidelines given below are followed, rubber gaskets or gasketed components have the following expected shelf life:

storage life gaskets

Tips for Gasket Storage and Shelf Life

Tip #1: Limit exposure to light

Sunlight and strong artificial light can degrade some gasket materials. For this reason, rubber gaskets should be stored in cartons or opaque bags which prevent direct exposure to light.

Tip #2: Maintain relative humidity levels

Very moist or excessively dry conditions in a storage location should be avoided. Relative humidity levels below 75% are recommended for most rubber gaskets. Similarly, very low humidity levels which can cause some materials to dry out and become brittle should also be avoided. Continue reading Tips for Gasket Storage and Maximizing Life

Gaskets Designed to Take the Heat

Under pressure? Absolutely. The increasingly high temperatures and harsh conditions to which gaskets are exposed makes selecting the right gasket all the more important.


In industries such as chemical processing, hydrocarbon refining, and power generation, leakage from extreme temperature process  streams can result in loss of efficiency and production as well as adverse environmental impacts and compromised employee safety. One of the most commonly used sealing products in systems subject to high pressures and temperatures is a spiral-wound gasket. These gaskets typically consist of filler and winding materials selected on the basis of application requirements and end-user preference. Proper selection of these materials is critical to achieving the desired performance in all applications.

Material Selection

Sealing at temperatures above 850 ºF (454 ºC) is particularly challenging because of the limited number of filler materials that can resist thermal degradation at extreme temperatures – these temperatures affect both the sealing material and metal components. For instance, the yield strength of fasteners decreases as the temperature is increased. In addition certain chemicals can become more volatile and aggressive in high-temperature reaction processes.

The two most common filler materials in spiral-wound gaskets are graphite (can withstand temperatures up to 850 ºF) and polytetrafluoroethylene (PTFE; tolerance up to 500 ºF). Other filler materials are used mainly for their thermal insulating properties, not for sealability; these include mica, exfoliated mica, and ceramics. While graphite and PTFE perform satisfactorily in terms of temperature and chemical resistance, they have limitations. Graphite is not compatible with heavily oxidizing media at any temperature, nor can it withstand continuous operating temperatures above 850 ºF. Beyond 850 ºF, volume loss through oxidation becomes excessive and sealing effectiveness is compromised.

Many high-temperature systems, such as exhaust manifolds and flanged piping connections in exhaust systems, are oxidizing. Other services are oxidizing because of the operating temperature and media involved. Continue reading Gaskets Designed to Take the Heat

Form-In-Place Gaskets: What They Are and What They Are Not

Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.

Original content can be found on Parker’s Website and was written by Ben Nudelman, Market Development Engineer, Chomerics Division.


Form-in-place EMI gaskets, also known as FIP EMI gaskets, is a robotically dispensed electromagnetic interference (EMI) shielding solution that is ideal for modern densely populated electronics packaging.

picture of CHOFORMThe most important distinction of form-in-place EMI gaskets is that they were developed for applications where inter-compartmental isolation is required to separate signal processing and/or signal generating functions.

Simply put, form-in-place gaskets are meant to reduce “noise” between cavities on a printed circuit board (PCB) or in an electronics enclosure.

In addition, form-in-place gaskets provide excellent electrical contact to mating conductive surfaces, including printed circuit board traces for cavity-to-cavity isolation. Parker Chomerics form-in-place gasket materials are known as CHOFORM.

7 reasons why form-in-place EMI gaskets can be an ideal choice

  1. Small form factor – form-in-place gaskets can be dispensed in smaller bead sizes than most traditional EMI shielding gasket solutions, 0.018” tall by 0.022” wide.
  2. Excellent adhesion – 4-12 N/cm adhesion on prepared surfaces such as machined metals, cast housings, and electrically conductive plastics.
  3. High shielding effectiveness – Parker Chomerics CHOFORM materials can provide more than 100 dB shielding effectiveness in the 200 MHz to 12 GHz frequency range.
  4. Quick programming – Because form-in-place EMI gaskets are robotically dispensed, a standard CAD file can be used to program the dispensing system and quickly map out the dispensing pattern.
  5. Complex geometries – The positional tolerance of the gasket can be held to within 0.001” and is able to follow very complex geometries including sharp turns, corners, and serpentine patterns. Other gaskets such as die cut sheets or o-rings manufacture and/or fabricate into such shapes and patterns.
  6. “T” joints – Traditional extruded gaskets are difficult to mate at intersections or “T” joints. The robot dispensing systems produce reliable junctions between bead paths to provide continuous EMI/EMC shielding and environmental sealing.
  7. Integrated solutions – CHOFORM technology combined with a Parker Chomerics supplied metal or conductive plastic housing provides an integrated solution ready for the customers’ highest level of assembly. This approach requires no additional assembly or process steps for the installation of gaskets and/or board-level auxiliary components.

Picture of Form-In-Place EMI Shielding Gaskets

Form-in-place EMI gasket limitations

  1. Large form factor enclosure sealing that can accommodate a groove. For larger areas such as machined covers that can accommodate a gasket groove, other EMI shielding solutions are better suited. In most applications, conductive elastomers such as the CHO-SEAL product line by Parker Chomerics will provide better shielding and sealing. Form in place gaskets can be dispensed in bead sizes only as large as about 0.062” tall x 0.075” wide.
  2. Enclosures requiring submersion or durable weather sealing. Because of the small form factor, FIP gaskets will not meet stringent environmental sealing requirements such as IP 67 or higher. While silicone-based, the material is better at preventing dust and environmental moisture from entering an enclosure. FIP gaskets can be paired with additional sealing gaskets for enhanced weatherproofing.

Gallagher Fluid Seals is an authorized distributor for Parker. For more information about their products, including o-rings or their various compounds, contact Gallagher Fluid Seals today.

Raising the Gasket / Surface Profile in Aging Systems

Enhancing the surface profile can improve sealing capabilities, extending the functionality of aging piping systems in chemical plants.

There are many aged and aging process plants in operation today. In fact, many of the processing plants for power, chemicals, oil, etc., have been in service for more than 50 years. And while the piping itself may remain intact, their bolted flange gasket joints and connections are becoming misaligned, corroded and damaged due to repeated handling, chemical exposure and thermal cycling. This can lead to costly ruptures that may result in millions of dollars in damages, downtime, noncompliance penalties, irreparable environmental impact and litigation.

There is a solution that can extend the life of aging piping systems, preserving their functionality: raising the surface profile on polytetrafluoroethylene (PTFE) gaskets. This design modification can prevent leaks, spills and other releases in chemical processing plants by reducing and managing the contacted area of the gasket, thus achieving and maintaining a strong seal.

A Brief History of Gasket Technology

Traditionally, gasket thickness and sealability always involved a performance tradeoff. One could use 1/16-inch-thick (1.6 millimeter) gaskets when flanges were in good condition, achieving a tight seal with reduced creep.

However, when the flanges had bad or misaligned surfaces, the seal integrity was degraded.

In those instances when the flanges are in poor condition (or if the shape of the flange condition is unknown), one would choose a 1/8-inch-thick (3.2 mm) gasket. The reason? A user does not want to risk installing a thinner gasket and discover that it does not seal properly, which then requires a timely and costly uninstall and reinstall. However, the thicker gaskets do not seal as well as their 1/16-inch counterparts when placed under comparable load. Additionally, with the thicker gaskets, creep is higher, requiring re-torque.

To address the limitations of both gasket options, the ideal gasket should combine the creep resistance of a 1/16-inch gasket with the compressibility and conformability of a 1/8-inch gasket—easier said than done.

Historically, gaskets have not always been forgiving, easy to use or simple to remove. Yet technology has evolved, allowing sealing products to be engineered and designed to optimize the work that is put into them, delivering a tighter, more durable seal.

The approach is one that does not focus on the gasket thickness but rather its surface profile. The results produce gaskets that reduce leaks, spills and other releases from piping systems, including those of aging chemical plants.

gylon epix sheet
Gylon EPIX Sheet Material

Raising the Gasket Profile

The concept of using surface profiling to reduce area and increase stress is found in many products, such as running shoes and car tires. Reducing the contact area while maintaining a given amount of compressive force results in increased stress. In the case of shoes or tires, this stress provides traction. In the case of gaskets, traction or friction between a gasket and a flange face is critical to holding internal pressure. If the downward force created by the fasteners in a flange is evenly spread over a larger area, the created stress contributes to making a seal more effective. This approach enables the aging piping system to maximize its sealing potential.

Impact on Raising Gasket Profile

Surface profiling positively impacts gasket technology in five key areas: compressibility, pressure resistance, scalability, load retention and dimensional flexibility.

Compressibility

Compressibility is a critical functionality of gaskets, as it represents the ability of the gasket to conform to the surfaces that it seals. Adding raised features to the surface of a gasket directly impacts compressibility by reducing the contact area and increasing the resulting stress.

When flange surfaces are worn, pitted or scratched—such as those in aging piping systems in chemical plants—it can be cost prohibitive and nearly impossible to repair/replace the flange to a “good as new” condition. The more compressible the gasket, the better chance of producing an effective seal with the flanges. Continue reading Raising the Gasket / Surface Profile in Aging Systems

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

Form-in-Place Sealex® Joint Sealant

Sealex®Sealex® joint sealant, specially processed, 100% pure PTFE on a roll, provides soft, highly compressible gasketing for longer life and trouble-free sealing. Its form-in-place versatility also cuts maintenance and storage costs. The high compressibility of Sealex® enables it to effectively fill flange imperfections for a tight, leak-free seal. Under pressure, it provides a very wide, thin ribbon-like joint sealant. Unlike conventional PTFE which is prone to cold flow, Sealex® has good creep resistance and bolt torque retention properties.

Sealex® joint sealant does not support bacterial growth or cause product contamination and is FDA compliant. It has virtually no shelf-life concerns since PTFE is unaffected by normal environmental conditions.

It has excellent resistance properties to chemical attack. It is ideal for most chemical services at temperatures to 500°F (260°C) and pressure to 2,000 psi (138 bar). It is also suitable for cryogenic use to -321°F (-196°C).

Continue reading Form-in-Place Sealex® Joint Sealant

Isolation Gasket Solutions from Thermoseal

KLINGERSIL® C-7400 Isolation Gaskets

Application Overview:

Some applications in plants call out for isolation kits to maintain the integrity and reliability of a pipeline and piping system. Isolation kits are designed to work in conjunction with flanges, gaskets, and/or bolt sleeves and washers by eliminating metal-to-metal contact and halting static electric currents. At times they are relied upon for critical applications in severe temperatures and conditions.

KLINGERSIL C-7400 - Isolation Gaskets replace Isolation Kits

The Problem: 

Industry’s first choice are phenolic gaskets. They are often supplied in kits, but they are hard and typically take a lot of load to seal. And lack of load is the number one reason for gasket failure.

Continue reading Isolation Gasket Solutions from Thermoseal

Improper Gasketed Joints Can Be Deadly

Gasket FabricationGallagher Fluid Seals is the trusted supplier of MRO sealing materials – including gasketing, packing, expansion joints, etc. – to all kinds of plants and manufacturers throughout the northeast and mid-Atlantic.  At Gallagher, we take the time to specify the right gasket for every application, and we do our best to keep our customers well-informed about industry best practices and sealing safety.

The following is an article recently published in Pumps & Systems Magazine, which discusses why you should NEVER reuse a gasket.


Sealing Sense

by Jim Drago & Ron Frisard

Safety is a concern at any industrial site. An Occupational Safety and Health Administration compliance specialist has stated that safety should be more than a priority: “Priorities in an organization can and usually do change. Safety and health need to be a core value of the organization.”1

Continue reading Improper Gasketed Joints Can Be Deadly

How To Choose The Right Semi-Metallic Gasket

semi-metallic gasketThere are many variations of semi-metallic gasket available in today’s market.  The combination of metal and a soft gasket material merges the sealing ability of the soft material with the structural integrity of the metal.

The most common styles of semi-metallic gasket include spiral wound gaskets, corrugated, jacketed, and kammprofile gaskets.

Pumps & Systems magazine outlined the proper way to select a semi-metallic gasket. Read on to learn more:

Continue reading How To Choose The Right Semi-Metallic Gasket