Why Gaskets Are Used?
To prevent the passage of any media between two stationary members a compressible element that is made of combination of materials is clamped between those members. That compressible element is the “GASKET”.
The gasket material selected must be capable of sealing mating surfaces, resistant to the medium being sealed, and able to withstand the application temperatures and pressures.
Gaskets are classified as:
- Soft cut Gaskets
- Semi metallic gaskets
- Metallic Gaskets
The physical properties and performance of a gasket will vary extensively, depending on the type of gasket selected and the materials from which it is manufactured.
Physical properties are important factors when considering gasket design and the primary selection of a gasket type is based on the following:
- Temperature of the media to be contained
- Pressure of the media to be contained
- Corrosive nature of the application
- Criticality of the application
Soft Cut Gasket
- Sheet materials are used
- Low to medium pressure services.
- Suitable for extreme chemical services and temperatures.
Examples: Non-asbestos Fiber Sheets, PTFE, Insulating Gaskets, Flexible Graphite Gasket, Asbestos Gasket.
Semi Metallic Gasket
- These gaskets consist of both metallic and non-metallic materials.
- The metal provides the strength and resilience for the gasket.
- The non-metallic component provides the conformable sealing material.
- Suitable for low and high pressure and temperature applications.
- A wide range of materials are available.
Examples: Spiral Wound Gaskets, Kammprofile Gaskets (covered serrated metal core), Metal Jacketed Gaskets, Metal Reinforced Gaskets.
- These gaskets can be fabricated in a variety of shapes and sizes
- Used in high pressure/temperature applications
- Except for weld ring gaskets, high loads are required to seat metallic gaskets, as they rely on the deformation or coining of the material into the flange surfaces.
Examples: Ring Type Joint Gaskets, Lens Rings, Weld Ring Gaskets, Solid Metallic Gaskets.