What is the Correct Gasket Material for Your Next Project?

When something works well, you likely won’t even notice. In manufacturing, well-running machines result from precise engineering done using the right components to make for a smooth, dependable, and quiet experience. 

Your search for suitable gasket material will leave you with an abundance of options, but how do you know when you’ve found a gasket material that can provide you with the right tolerances for an accurate fit?

At Strouse, we’ve had many clients approach us about figuring out which material suits their gasket. The key is looking at your different options and testing certain materials based on their favorable properties for your project.  

Before you engineer your next flexible material project read our overview of gasket materials to see what might function as a potential solution. 

Defining Gaskets

At its core, a gasket is meant to prevent matter from passing from one place to another, be it a liquid, gas, or energy discharge. Whether you need something to last a long time, resist heat and pressure, or avoid conducting electromagnetic resonance, a gasket exists to meet that need. 

While the purpose of any gasket is to maintain a seal between two elements, a variety of shapes and types of gaskets are employed depending on the situation.

Common Types of Gaskets

The type of gasket you use depends on many different factors, including your application, substrates, and the intended length of use.

PIPE GASKETS

Simple joints, like those found in pipes, use pipe gaskets. These are circular and usually require a higher tolerance for compression. A pipe gasket must also resist corrosion and extreme temperatures to maintain its shape over time.

A combination of metallic, non-metallic, and composite materials ensures that each joint remains sealed. As versatile as they are, pipe gaskets aren't a one-solution-fits-all endeavor, so you’ll still need to ensure appropriate measurements and materials.

JACKETED GASKETS

The most employable of gaskets is the jacketed type. Jacketed gaskets provide flexibility from a soft core and resilience with an external coating.

With jacketing, one surface of a gasket may be covered with a metal material on both sides. A product is referred to as “double-jacketed” when both sides are wrapped around a softer core. Double-jacketed gaskets provide better corrosion resistance over single-jacketed gaskets, as there is less possibility of material seeping into the core.

Another type of jacketed gasket is the corrugated jacketed gasket, which interweaves materials in layers, making for specialized combinations of flexibility and durability.

SPIRAL WOUND GASKETS

Like a jacketed gasket, spiral wound gaskets seek to combine the best of both worlds. These use a combination of metals and plastics (or rubber) wound around metal layers.

The resulting gasket yields acute physical resistance to stress and high heat. The gasket remains rubbery, so it seals well in moving joints and where fluids, gasses, or heat exchange is needed.

KAMMPROFILE GASKETS

Kammprofile gaskets can be thought of as a jacketed spiral wound gasket. A corrugated metal core is covered in a sealing material on both sides with this type of gasket.

The kammprofile gasket uses physic stress to focus tension onto the surface sealant to form a seal. This process leverages the different core materials to the sealing material to effectively reduce stress and transfer heat without further deformation.

SOLID GASKETS

Solid gaskets are metal gaskets that are inexpensive and easy to use. They are used in high-thermal and high-pressure situations and require immense compression force to form a seal properly.

Solid gaskets are most commonly used between two other dense surfaces that are harder than the gasket material, and the majority of solid gaskets are formed from metals.

Additional Gasket Materials

The material used to create a gasket aids in the final function. Some gaskets offer a higher level of resilience to a particularly damaging agent or force. Others provide durability and flexibility to create a tight seal and keep operations running for a long time.

It's important to remember that there are enough combinations of types and materials for gaskets that not everything has been attempted. If you’re facing a novel engineering problem, it will require a novel solution, which could even warrant a custom gasket.

Take a look at the following gasket materials, which can further assist your manufacturing project development.

GASKETING TAPE AND ADHESIVE

Not all gaskets fit into a contained system. Doors and windows must retain tight seals when closed while allowing people to open them freely. Threads and other locking components need help to reinforce mechanical seals and reduce friction that creates unconformities.

Gasketing tape, or pressure-sensitive tape made from polymers and metals, can be applied in these situations. The material expands to create a seal and deforms to allow the seal to break with mechanical motion. The result? A reduction in noise and the containment of fluids, gasses, and heat while remaining flexible through weathering and impact.

On the other hand, thread tape fills in gaps to create a tighter seal while also reducing the friction that can develop locks that split or break the threads from vibrations or percussive force.

GASKETING FOAM

Foam gaskets are another option for applying seals to materials, particularly irregular shapes or covering large surface areas. In some cases, foam is used much like tape, where a backing layer is attached to one surface and the foam is uncovered from a surface protection film before the seal is completed.

Foam can also be sprayed in an application which puts the maximum amount of material into a gap between two other materials. Foam gaskets applied via spraying do well for noise and impact reduction projects. The seals are less tight than those created by other gasket types, and the material is far less dense.

Heating, Ventilating, and Air Conditioning (HVAC) industries use foam gaskets to reduce heat exchange between components or provide extra seals on vents. These gaskets can slow fluid (like refrigerant) and gas leaks, though not prevent them altogether. 

Though foam may lack some durability, that’s made up for by the ease of reapplication. Foam gaskets work well in conditions where other components need frequent repair or replacement.

SILICONE GASKETING

Silicone materials are created from silica sands and can be used at a wide temperature range, from 400˚ F all the way down to -67˚ F.

Silicone gaskets withstand aging and weathering well. The high elasticity of silicone makes it great for troublesome angles. That said, if you need a seal against solvents, fuels, or silicone-based fluids, silicone seals won’t cut it. Each of these materials quickly degrades a silicone gasket.

NEOPRENE GASKETING

Neoprene is a synthetic polymer rubber. It provides high tensile strength for areas that often move, even under stress, as a gasket material.

Neoprene gasketing works in a temperature range of 230˚ F to -40˚ F. While not as high or low as silicone, it is still usable in a wide variety of environments. Neoprene does well with compression as a rubber polymer but isn't as tough as some other materials.

Neoprene ages well and won't crack or bleach under sunlight. It resists oils, including grease and silicone oil. The tight pores of the polymer are excellent at resisting damage from gasses such as refrigerants, carbon dioxide, and ammonia. While there may not be particular weaknesses to pinpoint, neoprene is a middle-of-the-road option for many of its benefits.

EPDM GASKETING

Ethylene propylene diene monomer, or EPDM, is another synthetic rubber polymer offering a variety of resistances. The material is made from polyethylene and propylene with a crystallinity that gives it elastic properties.

EPDM gaskets offer excellent resistance against oxygenation, weathering, ozone, and heat, making excellent electrical insulators. Their operational temperature range goes from 250˚ F to -40˚ F, but EPDM doesn't do well with petroleum fluids or oils, which you’ll need to keep in mind.

TEFLON (PTFE) GASKETING

Teflon is technically a brand name, but it’s a common shorthand for polytetrafluoroethylene, or PTFE. PTFE provides extreme resistance to corrosion as it offers a tight surface that restricts the ripping and tearing of bonds.

PTFE gaskets also provide remarkable temperature resistance ranging from 500˚ F to -328˚ F. The material is non-flammable and weathers exceptionally well. The low coefficient of friction and lack of adhesivity may be helpful or an obstacle, depending on how you’ll need it.

PTFE does have a perceived drawback when used in water transportation and food devices. Older production runs of PTFE utilize PFOA (perfluorooctanoic acid), which releases a toxic gas at high temperatures. Current PTFE manufacturing, however, uses alternative chemicals to avoid this problem.

GORE-TEX GASKETING

Like Teflon, Gore-Tex is a name-brand ePTFE (expanded polytetrafluoroethylene) material. It has many of the same properties as PTFE but expands to provide better flexibility. Gore-Tex ePTFE is used in places where stability is critical since it avoids intrusions and flaring.

This gasketing material operates at the same temperature ranges as standard PTFE—500˚ F to -328˚ F—and it’s strong against corrosion and solvents. You’ll want to consider this material's notable weakness: its trouble with exposure to alkali metals and elemental fluorine.

GRAPHITE  GASKETS

Graphite is another robust and non-porous material that works well for gaskets. Graphite gaskets provide excellent compression characteristics and transfer performance and offer a substantial temperature range of 950˚ F to -400˚ F. The lattice structure and density of graphite make it ideal for reducing danger from gasses and particulates.

Nuclear-grade graphite is used to slow reactions in reactors. When made into gasket material, it is combined with polymers and metal cores to provide flexibility and reduce brittleness.

Graphite can be interwoven with many secondary materials to create the desired product. These include wire mesh, steel foil, tin-plated carbon steel, and stainless steel foil.

BUTYL

Butyl rubber polymer combines isoprene and isobutylene. Butyl rubber gaskets provide low moisture and gas permeability and protect against aging, abrasion, weathering, and ozone.

The material operates well at temperatures between 248˚ F and -67˚ F and is an excellent electrical isolator. While it works well against hydraulic fluid, it is not recommended for contact with petroleum fluids.

NITRILE 

Nitrile (NBR, Buna-N) is the go-to for petroleum oils and gasoline. Other acids, bases, and especially aliphatic hydrocarbons are resisted. Nitrile polymer has a lower temperature tolerance than many options, ranging between 212˚ F and -40˚ F.

Nitrile gaskets offer high compression resistance against permanent compression but have low reformation properties and do poorly against weathering, ozone, and sunlight.

SBR

If you need a natural rubber feel with enhanced characteristics, styrene-butadiene rubber (SBR, or Buna-S) is the way to go. SBR provides better water resistance but still lacks resistance to solvents and related chemicals. It ages well and performs at higher temperatures ranging from 158˚ F to -67˚ F. In excessive heat, however, it can harden and become brittle.

NATURAL RUBBER

Natural rubber is both difficult to come by and of mild performance. Its best characteristic is its high tensile strength and tear resistance. Plus, it's hard to beat the water resistance it provides.

Natural rubber operates between 122˚ F and -67˚ F, which can be helpful in some moderate or lower temperature conditions. While it offers certain benefits, it generally doesn’t age or heat as well as polymers and synthetic rubbers.

COMPRESSED ASBESTOS-FREE GASKETING

Compressed asbestos-free material is a synthetic fiber composed of elastomeric binders and fillers. This material creates high heat resistance and long-term sealability and has a safe temperature range of 400˚ F to -40˚ F with an operation spike survivability of 700˚ F.

Compressed asbestos-free gaskets do well against water, hydrocarbons, and inert gasses and make a solid general-purpose material. However, they only excel in temperature resistance in comparison to other materials.

The Importance of the Right Gasket Material and Tight Tolerances

How can you use all these different gasket materials? The possibilities are too numerous to count. With so many gasket materials, you can only expect the best results and cost-effectiveness when you find the right gasket material your project needs. This is going to require testing and you may want to enlist the help of an experienced converter to guide your selection process.

Precision is critical in selecting the right gasketing applications and materials. Each type of gasket has unique specifications, and it’s vital to use the right one and have the correct measurements in place. You want the kind of seal that works so well you won’t even notice it.

Having the right gasketing materials is only a part of the process— what’s your manufacturing plan? A flexible material converter can help you bring your product from conception to completion. 

Consider reaching out for a flexible material consultation or taking a look at our Learning Center to see the best production options for your unique design.