NON METALLIC GASKETS - AVOIDING LEAKS AND BLOWOUTS

 https://www.plantengineering.com/articles/nonmetallic-gaskets-avoiding-leaks-and-blow-outs/

"The compressive stress on a gasket plays a larger role in its ability to maintain pressure than its tensile strength.
By Dave Burgess October 1, 1999

The compressive stress on a gasket plays a larger role in its ability to maintain pressure than its tensile strength. Why is this significant? It is the reason for many gasketed joint problems!

In a classic scenario, a joint is assembled without controlled bolt loads; that is, without known and controlled bolt torques. The joint withstands a hydro test at 1.5 or 2 times rated pressure, yet leaks or blows out after a period of service at pressures well below the test pressure.

Was this failure due to a loss of gasket tensile strength? Probably not. Gasket tensile strength alone cannot be counted on to hold system pressures. What very likely occurred was loss of compressive stress on the gasket."

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