Sounds like a good question to ask of some person or company that has done
some genuine research. Anybody know of a source?
I know that at the company where I worked prior to my present occupation,
they spent several hundred thousand dollars for an automated head-torquing
machine in their engine plant (big diesels). They torqued different head
bolts to different torques, and the multi-spindle machine that did it was
programmed on some bolts to tighten, back off, and re-tighten.
In another application, in the manufacture of extremely close tolerance
hydraulic assemblies, the same kind of thing occurred. There, the automatic
numerical controlled bolt-tightening machine also made two passes to
compensate for initial gasket relaxation. I sure that Mordy is right about
solid gaskets --but I'd like to learn more from somebody in the composition
gasket business.
uncle jack
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