Seals, Gaskets & Packings

When trying to choose between a gasket and seal, your first impression might be that they are the same thing. After all, they perform essentially the same function, right? In some ways, they are certainly the same, but there are some important differences that you should understand when deciding which one is right for your project. Gaskets seal a connection between two components or flanges that have flat surfaces, while seals are used between engine parts, pumps, and shafts that rotate.

Gaskets seal a connection between two components or flanges that have flat surfaces, while seals are used between engine parts, pumps, and shafts that rotate. Gaskets are used wherever a union or flange is required to prevent leaking. Gaskets are most commonly used as static seals.

As already mentioned, seals are used between engine parts, pumps, and shafts that rotate rather than those that are static. This type of seal is generally a molded or machined product. Seals tend to be flat and round, while gaskets are often cut into different shapes so that they fit the components. Most seals are made of an outer ring that is metal and nests over an inner surface that is often made of rubber. The inner circle is tilted just a bit, which creates a lip for the seal. The lip is designed as a second barrier against any drops that manage to get past the first edge of the seal. It is essential that seals be installed correctly because, if it’s installed backward, you could end up with a leaky mess on your hands.