Difference Between Gaskets and Seals

It is a common misconception that gaskets and seals are the same things.

While they do have similar functions in preventing leaks, gaskets and seals have different applications. In general, gaskets are used as static seals between flat surfaces, such as joints, while seals are used in dynamic environments between moving parts, such as rotating shafts, pumps, and engines.


What are gaskets?

Gaskets are rings or sheets of flexible material used in static applications to seal joints, flanges, and other mating surfaces to prevent leakage.

Depending on the material and application, gaskets can be produced using a variety of manufacturing techniques, including

Rubber extrusion

Hot vulcanization and cold bonded splicing

Compression, injection, and transfer molding

Precision slitting

Custom die-cutting

Waterjet cutting

Gaskets and seals can be found in virtually all applications and industries, including oil and gas, manufacturing and industrial applications, pulp and paper production, and agricultural equipment.

Worn or damaged gaskets are easily replaced. It is often recommended that gaskets be replaced when disassembling and reassembling equipment.

Large Gap Ultra-high-pressure Sealing Components

Large Gap Ultra-high-pressure Sealing Components


What Is a Seal?

Seals are a broader category that includes O-rings, valve stem seals, rotary seals, and mechanical seals. Unlike gaskets that are typically used in static applications, seals are found in more active environments such as motors, engines, pumps, and rotating shafts.

Seals tend to be flat and round, with an angled rubber inner ring surrounded by a metal outer ring. The sloping angle of the seal’s inner layer helps prevent leakage in dynamic applications. Seals are typically used to prevent leakage between two moving parts and to prevent particles and contaminants from intruding into the system.

The process of replacing a broken or damaged seal can be very complex. Not only the seal, but the entire assembly may need to be disassembled to gain access to the seal and allow for replacement.


What’s the Difference Between a Gasket and a Seal?

Seals are a category and gaskets are one of the important types of seals. In addition to gaskets, you can find several other forms of seals such as shaft seals, mechanical seals, stem seals, liquid sealants, O-ring seals, rotary seals, and more.

The process of manufacturing seals involves extensive machining and specific sizes of seal materials. It is referred to as an engineered product and is designed for special conditions. Seals are also known for displaying characteristics that gaskets cannot provide. This is why seals can provide better functionality compared to gasket products.

Internal Expanding Sealing Components

Internal Expanding Sealing Components (Type NM)

A gasket is known as a static component that can be used to seal a leak between two static components and does not show any relative movement. On the other hand, a seal is a dynamic component that is used to avoid leaks between two components that show sliding or relative motion. Another essential function of a seal cover gasket is that it does not allow foreign objects such as dirt or dust to enter the joint.

If the gasket is damaged, you will need to replace the existing gasket with a new one. However, when the seal is damaged, you need to replace it with a new seal and bearing. In this application, gaskets are very convenient compared to seals.

Both gaskets and seals are used to prevent fluid from moving from one direction to another due to compression forces. However, a gasket is an immovable object that cannot be moved once it is placed in a specific position. An oil seal, on the other hand, can be moved very quickly from one position to another.

Another fundamental difference between gaskets and seals is that gaskets are usually made of hard plastic or asbestos materials. On the other hand, seals (especially oil seals) are made of materials such as synthetic rubber.

This is a detailed explanation of the difference between gaskets and seals. It will certainly give you an insight into how the mechanisms of both products work. Understanding the nuances between these two items is essential to the successful execution of any project. Once you understand the typical features and unique functions of gaskets and seals, you can definitely choose the right component for your project.

Let us help you find suitable sealing components for your project. When you contact us, please provide your detailed requirements. That will help us give you a valid quotation.