Re: pressure test thoughts

From: <Christopher>
Date: Thu Sep 08 2005 - 14:22:00 EDT

On Sep 8, 2005, at 12:06 PM, George McKinney wrote:

> At a later date, they wanted a higher rating. So, checked
> calculations, re-tested, and re-certified at the actual capability.
Who re-certifies it? Here in Minnesota you could probably do that as what's called a 'Minnesota Special' but strictly speaking it hasn't been re-rated, since it the working pressure is no higher than the original MAWP.

Why would anyone go the the trouble of testing and stamping for the lower pressure? Unless the vessel was corroded or damaged the original MAWP qualifies it for service at any pressure up to and including the MAWP. No re-testing is required. Had it been damaged and then de-rated? If so, you couldn't re-rate it until it was fixed. Again, by National Board rules.

Christopher Wright P.E. |"They couldn't hit an elephant at <a href="/group/PipingDesign/post?postID=Wlut8prVQ1Oclf5OUepNLTBFndpae3-K8BFW5rgeIaO-EKG39m9rO6ipzTg3NNdnpGO4HXns3HLTzHhG">chrisw@skypoint.com</a> | this distance" (last words of Gen.

.......................................| John Sedgwick, Spotsylvania

1864)
<a href="http://www.skypoint.com/~chrisw/">http://www.skypoint.com/~chrisw/</a> Received on Thu Sep 08 14:22:00 2005