Over
compression of gasket material is a common
problem with metal gaskets which have mechanically
designed recovery built into the gasket. Over
compression removes the gasket materials
ability to recover. This is also true of expanded
PTFE (Teflon
®), once over compressed
it will have no recovery and therefore will not
longer adapt to maintain a seal.
The common strategy of "The more
compressive load exerted on the gasket, the longer
it will last" is generally true of elastomeric
materials since elastomers (rubbers) are not
compressible but deflect compression. Many
materials such as non-asbestos compressed gasket
materials and beater addition (ie; Armstrong)
materials contain elastomers in the mix of material
they are produced from, making them difficult to
over compress.
One
of the more desirable properties of an effective
gasket material in industrial applications is the
ability to withstand high compressive loads. Most
industrial gasket applications involve bolts
exerting compression well into the 14 MPa (2000
psi) range or higher. This is why Non-asbestos
gasket materials are so widely used in industrial
gasket material applications.>>The
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