Itamarjr
Whether or not a gasket needs to be safety-related depends upon where it is used. It's hard to give a general answer, because (1) different countries have different requirements and (2) different plant designs or systems have different requirements.
In the U.S, nuclear plants have to follow Title 10 of the Code of Federal Regulations. Part 50, which applies to currently licensed operating reactors, contains a number of requirements which would apply. So before you start a wholesale downgrading of gaskets, you would need to determine if its parent component was safety-related. Then you'd need to decide whether the gasket actually performed a safety-related function (often it doesn't, but not 100 percent). Then you'd have to decide whether the gasket could be procurred commerically and used as-is, or whether it could be procurred commercially and would need to be upgraded (i.e., some type of review required to make sure it would perform satisfactorily in service), or whether you had to buy a safety-related component with the full pedigree.
Patricia Lougheed
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.