Multiple component parts UG-101(m) 1

[buggybubble]

We burst an assembly that is comprised of elastomer elements, 316SS elements, aluminum elements and cast iron elements. Which one is to be the determining component part for the final MAWP derived from UG-101 (m) equations? Each material yields a different MAWP depending upon the casting factor f, the efficience E (for welded).

Help!

Thanks.

 

[SnTMan]

The lowest component MAWP governs the assembly. That's pretty clear.

Regards,

Mike

 

[buggybubble]

Thanks for your reply.

The trouble we are having is that the burst was due to the yield of the elastomeric parts, and not due to the metallic parts. In particular, the 316L part, which is welded, was determined under UG-27 to be strong enough, and the aluminum components were shown to be strong enough by calculation. However, UG-101 (m) requires the input of the minimum tensile strength and the elastomeric materials in use do not have minimum tensile strength values. The lesser of the two metallic component strengths is the Aluminum. So is Aluminum the component part of lesser MAWP to be used in the UG-101 (m) equation? (of course your opinion is based on very limited information and can't be used authoratively, but it is very welcome as another perspective on the issue).

 

[buggybubble]

Thanks for your reply.

The trouble we have is that even though the lowest MAWP component part is to be used in UG-101(m), we determined that the lowest MAWP component part is the elastomeric component, for which there is no clar specified minimum tensile strength (because it is elastic). The o-ring is sandwiched between a welded and an aluminum plate. Of the two materials, the aluminum is clearly weaker. Burst failure was due to the 0-ring failure. Of the two metallic components, what criteria should be chosen to decide which to use as the component part under UG-101 if neither appeared to contribute to the failure?