Gaskets come in a boundless array of shapes, sizes and materials, but they all do the same job. Gaskets exist to seal gaps. It might be the gap between two pipe flanges, the gap around an electrical cabinet, or even the gap between two pieces of ducting in an a/c system, but the gasket’s job is always the same: fill that gap.
Flexible foam fabrications are often a good choice for gasket material. There are many different types of foam but most are lightweight, can be cut into various shapes, and may be purchased pre-laminated with pressure sensitive adhesive (PSA) for ease of installation. Most importantly, most foams compress readily and do an excellent job of sealing out, (or keeping in,) fluids, gases, dusts and other contaminants.
For a fabricated foam gasket to perform as needed it must be matched to the application. That demands a good appreciation of the following:
- How gaskets work
- Typical gasket applications
- Key performance characteristics
- Environmental factors
- Foam gasketing materials available from Merryweather.
How Gaskets Work
If surfaces like pipe flanges and cabinet doors could be made perfectly flat there would be no gaps for fluid to leak through. In the real world though, surfaces are far from flat. Sheet metal panels inevitably have undulations that cause varying gaps as a door is closed and pipe flanges have machining marks that create leak paths. And even if the surfaces were smooth, alignment tolerances would still create gaps of varying widths.
A gasket is a piece of compressible material fitted between two surfaces that will be clamped together. It’s job is to prevent leaks from or through the joint. Being soft, it squashes down more where the gap is smaller while remaining thicker for wider spaces. Its softness also lets it flow into small indentations on the two surfaces, blocking even microscopic leak paths.