Understanding how to create the perfect gasket design isn’t complicated at all. But it’s always helpful to learn the tips and tricks. Read on.
Gaskets are uncomplicated but highly essential elements used extensively in industrial systems. They work as seals between components of mechanical assemblies, compressors, and pipes.
Even though it is important to tightly link surfaces – such as pipe faces, etc. – it is practically impossible to fabricate perfectly smooth junctions. Moreover, corrosion can, in most cases, introduce brand-new phenomena over time.
Gaskets help to eliminate this problem by maintaining air-tight seals between components. This ensures efficient and highly consistent performance under a wide range of operating conditions.
This ultimate gasket design guide covers what a gasket is, the different types of gaskets you need to know, gasket materials, and so much more.
What is a Gasket?
A gasket is a very flat, mechanical component primarily designed to seal 2 much larger mechanical components when connected. In other words, gaskets fill the space between 2 or more mating surfaces in order to prevent leakage into or from the joined objects while under severe compression.
Gaskets come in several varieties, which range from simple but popular O-ring to much more complex custom designs. The latter usually come with several openings of different sizes and shapes.
However, irrespective of these variables, and in most cases, gaskets function as seals in pipes and prevent leaks. In a few cases, gaskets are employed to dampen vibration and sound or maintain appropriate compression levels in a system.
The Different Types of Gaskets
Gaskets are available in many different styles in order to be suitable for different industrial environments. They have varying thickness, different shapes, as well as a combination of openings that allow them to fit between 2 faces easily.
Here are some of the different – and popular – types of gaskets you need to know:
- Kammprofile Gaskets
This type of gasket has a metal core, and a non-metal material surrounds this core on the top and bottom. It efficiently creates a tight seal along the edge of the gasket, especially when extra reinforcement is used.
Kammprofile gaskets are also much easier to fix or repair compared to composite gaskets.
- Jacketed Gaskets
Jacketed gaskets come with soft, non-metallic interiors as well as a metallic coating. They come in several varieties – single-jackets (i.e., coating on one side) or double-jackets (i.e., coating on both sides) – corrugated jackets, etc.
The metallic coating that jacketed gaskets showcase gives non-metallic gaskets a much better resistance to severe damage.
- Spiral Wound Gaskets
The spiral wound gasket comes with windings of metallic materials and combines flexibility and resistance to damage. This type of gasket finds extensive use in pumping and piping systems due to its highly reliable seal.
- Solid Gaskets
These gaskets are made of solid metal and are incredibly durable. However, this type of gasket requires a tremendous amount of compression force in order to create a satisfactory seal.
Gaskets, in general, are designed to meet different specifications such as:
- Meeting stress relaxation requirements or retaining loads
- Heat or chemical resistance
- Containment of greases, liquids, etc.
- Severe environments
Gasket Materials
Before you order and install a new gasket, it is vitally essential to ensure that the gasket is made with a suitable material for your design or application. Gaskets can be made with the following materials which serve different purposes and offer unique strengths and benefits:
- Neoprene Rubber
Neoprene Rubber is an extremely high resistant material. Gaskets made from this material are often used for marine and outdoor applications.
- Buna-N Foam
This type of gasket material conveniently meets UL fire extinguishing requirements. The material is a combination or a blend of neoprene, Buna-N, and vinyl.
Buna-N Foam inhibits the absorption of air, gases, water, and offers excellent resistance to oil.
- Abrasion-Resistant Rubber SBR
Styrene-butadiene rubber (SBR) is a hard material that provides a much better abrasion resistance than natural rubber. However, styrene-butadiene rubber is not usually recommended for use outdoors.
- Neoprene Foam
Neoprene Foam – otherwise known as Monarch – is a durable, flexible, and incredibly soft form-fitting sponge rubber. This material offers excellent moisture and thermal institution.
- Polyurethane Foam
This gasket material quickly bounces back to shape, irrespective of the extent of compression it undergoes. It is a material that ably withstands wear that is often caused by scraping and rubbing.
The construction of Polyurethane Foam’s cell allows the absorption of air, gases, and water. This is why it is best used for absorbing vibration and shock.
- Aramid/Buna-N
This gasket material is a blend of Buna-N rubber and aramid fiber. The result is a durable material capable of resisting ethylene, oil, and water.
Gasket Design: What to Consider
You should consider the following when designing gaskets:
- Material selection
The first gasket design consideration involves determining whether a particular application requires dense or sponge materials. You also need to consider closing force specifications in addition to the initial determination.
The major difference between a dense material and sponge material – from a design viewpoint – are as follows:
- A sponge cross-section is more suitable for situations or applications that require a low closing force, e.g. door seals on consumer-type products, etc.
- A dense section is best suited for applications requiring tremendous or extraordinary interference between 2 surfaces, e.g. bolting 2 components together within an industrial setting.
In both instances, material selection depends primarily on the attributes and physical characteristics required in the application.
- Sealing environment
What is the sealing environment like? Will there be cold or hot fluid present? What about solvents as well as the presence of other chemicals? Is the sealing application dynamic or static? Can the material ably withstand ozone and UV exposure?
Answer these questions truthfully, and matching the right material to the application becomes much easier.
- How the gasket will be attached
This is the third most vital consideration. Is a specific part going to be attached via a compression fit into a channel? Will the seal require the use of an adhesive? Will there be a particular type of mechanical attachment in play – such as nails, staples, or clips?
Other gasket design criteria include:
- Fastening methods
- Hardness – also known as durometer
- The shape of the profile
- Compound selection
- The size of the gap
Gaskets in Pipes and Compressors
Compressor gaskets are highly functional in sealing equipment from the elements. These gaskets are resistant to UV rays and are highly durable. This means they will never crack or warp from sun exposure.
Compressor gaskets offer the following benefits:
- Prevent the absorption of moisture
- Resistant to UV rays
- Reusable
- Capable of withstanding outdoor conditions
- Highly durable
- Ensure the compressor arrives in excellent condition
- Cost-effective
- Efficiently utilize manufacturers’ fasteners and covers, etc.
Pipe gaskets – also known as flange gaskets – are manufactured from various materials, including non-asbestos, rubber, and graphite. These gaskets are available as Inner Bolt Circle (IBC) – i.e. raised face or ring type – and as Full Faced – i.e. with bolt holes.
- Inner Bolt Circle (IBC) Gaskets
IBC (Inner Bolt Circle) gaskets are also referred to as raised face or ring type. They sit well within the circle of the bolts that secure the joint. They are exclusively a continuous ring of material.
- Full Faced Gaskets
Full Faced gaskets cover the entire flange. You can easily recognize it since the holes for the bolts to pass through are usually cut right into the gasket material.
- Segmented Gaskets
This is another type of pipe gasket often used when the flange has an unusual shape, expensive or extremely large. Segmented gaskets are formed when 2 or more gasket parts are arranged with a tab, overlap, or shaped joint arrangement.
Therefore, when a segmented gasket is compressed, it will easily provide a continuous seal in the flange joint.
The Role of Gaskets and its Importance in Industrial Applications
The role of gaskets and their importance in industrial applications cannot be overstated. Gaskets create physical barriers between 2 distinct parts. They work by preventing things like dirt, dust, gases, fluids, as well as electrostatic discharges from inhibiting the overall functionality of engines from operating or performing at peak efficiency.
Conclusion
Gaskets play crucial roles as static sealing materials in engines, boilers, appliances, etc. As you can see, gasket design involves a lot of variables that must be considered in relation to the applications the gaskets will be subjected to.
This is why using the right type of material when designing gaskets is highly crucial, as this can engender joint integrity.