Originally Posted By: B Frech
I guess I've never really understood the determination of parameters for proof testing. If a a piece of machinery is built to withstand specific stress limits, how do you determine how far beyond those limits should be considered safe?


Suppose you need to design a pipe to withstand 12,000 psi. Because of life safety issues you multiply the 12,000 psi by a safety factor of 5 and get 60,000 psi. You then design the pipe to withstand up to 60,000 psi. Then you build the pipe and you subject it to a proof test of 24,000 psi.

I made up the safety factor of 5. I have seen them as high as 100 (cranes). I completely left fatigue stress considerations out etc...

Best,

Mike

Edit - Safety Factors are arbitrary to my mind. Based on experience and science and statistics I imagine.

Last edited by AmarilloMike; 04/25/08 10:53 AM.

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