All types of centrifugal pumps require high-quality gaskets for proper sealing. Based on your pump’s design and application, using the right gasket is important, especially if specific chemical or thermal resistance is required. A gasket is a type of static seal, which means there is no movement at the juncture being sealed.

In this article, we will cover what gasket pumps are and what type of gasket is used in pumps.

Gasket Types: What Type of Gasket is Used in Pumps?

For high-pressure applications, gaskets of the following types are generally used:

Non-metallic Gaskets

These gaskets are generally made from composite sheet materials, including elastomers (graphite, PTFE, etc.), aramid or glass fiber, or other flexible materials. They are typically used to seal flat-face and raised-face flanges in applications where somewhat lower pressures prevail.

Composite Gasket or Semi-Metallic

Composite gaskets combine metal and non-metal materials. Depending on the service requirement, different types of material combinations are possible.

Spiral wounds, Metal jackets, and Kamprofile gaskets are well-known in the composite gasket category. They are used in a vast range of pressure and temperature services.

Composite gaskets are cost-effective, unlike metal gaskets, but careful handling is required. Composite gaskets are utilized on raised faces, male-female, and tongue-and-groove flanges.

Spiral Wound Gasket

The most commonly used composite type gasket is a Spiral Wound Gasket. It’s suitable for a wide range of pressure and temperature classes. Normally, Graphite or PTFE is used as the filler material, and stainless steel or other exotic material is used as the winding material.

The spiral wound gasket has three components: an inner and outer ring, filler material, and winding material. Nevertheless, sometimes, an inner ring is not used. The image shows a spiral wound gasket with and without an inner ring.

The inner ring is utilized to provide additional support to the winding material. The winding is another layer of filler material and winding material. The winding material is a thin metal sheet, and the filler material is a soft material like graphite and PTFE.

Kamprofile / Campofile Gasket

The Kamm/ Cam profile Gasket has a solid metal core with concentric grooves. Filler material, either PTFE or graphite, is layered on this grooved metal ring. It’s Costlier than the Spiral wound gasket but offers better blowout resistance and is easy to handle even in large diameters.

Kammprofile gaskets are used in various service fluids and operating pressure-temperatures classes from Class 150-2500 flanges.

Metallic gaskets

There are two main types: metal jacketed and metallic gaskets for RTJ (Ring-Type Joints) flanges. Metal jacketed gaskets include a metal shell with a metal or non-metallic filler. The presence of the filler material offers the gasket resilience, whereas the metal jacket protects the filled core and resists pressures, temperatures, and corrosion. These gaskets are often used in heat exchangers, pumps, and valves. A limitation of these types of gaskets is that they require smooth and flat flange surfaces, as well as high bolt loads, to seal effectively.

The Importance of Gaskets and Considerations When Choosing the Right Gasket for Your Pumps

A flange joint leak can be disastrous—a flange leak leads to loss of product and energy. No plant operator wants to leak toxic or hazardous material that can harm the environment and humans. The gasket can help attain reliable sealing to avoid flange joints’ leaks.

When choosing gaskets, here are some considerations to keep in mind:

• Temperature – Gasket material must endure the entire design temperature range of the fluid it deals with.
• Pressure – Gasket material must endure the entire design pressure range of the fluid it handles.
• Corrosion resistance – The gasket material must not corrode when it comes into contact with the fluid it manages or when exposed to the environment.
• Types of fluid – If installed in a line that handles more than one type of fluid, the gasket material must be capable of handling different types of fluids.
• Robustness – The gasket must endure all movement due to pressure and temperature changes.
• Availability – The gasket must be easy.
• Cost – A cheap and unreliable gasket must not be used simultaneously; it shouldn’t be costly.
• Impermeability – The gasket shouldn’t be porous to the fluid being sealed.
• Compressibility – The gasket must press down onto the flaws on the flange surfaces to establish the initial seal properly and securely.
• Stress relaxation (creep resistance) – When subjected to load and temperature, the gasket should not show significant flow (creep). Such flow will enable the bolts to relax, lessen gasket surface stress, and lead to leakage.
• Resilience – Although normally stable, flanges move slightly relative to one another under cycling temperature and pressure. The gasket must be capable of compensating for such movements.
• Anti-stick – The gasket needs to be easily removable after use.

Where is a Gasket Used?

Gaskets are used in a vast variety of applications across many industries, where they are used to create a seal between two or more mating surfaces. Aside from centrifugal pumps, some common applications of gaskets include:

• Engines: Gaskets seal various engine components, such as the oil pan, cylinder head, and intake manifold, to prevent the escape of gases or fluids, such as oil and coolant.
• Piping systems: Gaskets seal connections between pipes, valves, and other components in piping systems to prevent leaks and ensure proper system functioning.
• HVAC systems: Gaskets seal ductwork and other components in ventilation, heating, and air conditioning systems, preventing air escape and ensuring proper system function.
• Electrical equipment: Gaskets are used in electrical equipment to seal enclosures and prevent the ingress of dust and moisture.
• Food and beverage processing: Gaskets are used in food and beverage processing equipment to avoid contamination and ensure product quality and safety.
• Aerospace and defense: Gaskets seal fuel and hydraulic systems in aerospace and defense applications and other critical applications where leakage could have serious consequences.

These are just a few examples of the many applications of gaskets. The type of gasket and material used depends on the application’s requirements, such as the temperature, pressure, and fluid being sealed.

What is the Difference Between a Gasket & a Seal?

When choosing between a gasket and a seal, your first impression might be that they are similar. After all, they perform essentially the same function. In some ways, they’re certainly the same, but there are some crucial differences that you must understand when deciding which one is appropriate for your project. Gaskets seal a connection between two flanges or components with flat surfaces, while seals are used between engine parts, pumps, and rotating shafts.

Gaskets help seal the connection between two parts or flanges with flat surfaces, while seals come into play between parts like engine components, pumps, and rotating shafts. They’re applied in situations requiring a tight seal to prevent leaks, commonly found in unions or flanges. Gaskets are primarily employed as static seals.

What is a Seal?

As mentioned, seals are used between engine parts, pumps, and shafts that rotate rather than static. This type of seal is often a molded or machined product. Seals are flat and round, while gaskets are often cut into various shapes to fit the components. Most seals are made of a metal outer ring that nests over an inner surface, often rubber. The inner circle is tilted for a bit, which produces a lip for the seal. The lip is a second barrier against drops past the seal’s first edge. Seals must be installed properly because, if installed backward, you could have a leaky mess on your hands.

Seals are commonly used to prevent leaks at the end of the shaft where they come out of the cover and seal hydraulic lines. This seal type is generally a molded or machined product. Seals are often used in bearings. A ball bearing is surrounded by a rubber seal, which stops it from leaking and sometimes lessens the noise during operation.

Are you looking for the right gasket for your centrifugal pumps? Please reach out to us today!