Talk:Hydrostatic test

It is fallacious to talk of pipelines as "lower pressure". Many pipelines currently operate at pressures in the 2000-4000psi (15-30MPa) pressure range.

"Pipeline hydrostatic tests are normally carried out at a minimum of 1.25 x operating pressure, not 1.5." -- This is wrong. According to ASME B16.5, hydrostatic pressure is equivalent to 1.5 times the stress ratio of hot/cold times the design pressure. It has nothing to do with 1.25 or the operating pressure.

Currently National Grid in the UK are testing a new pipeline and its associated AGI's to 150% of maximum operating pressure. —Preceding unsigned comment added by 81.133.224.124 (talk) 12:57, 11 August 2008 (UTC)

This is a very poor article. For example, 150% is not 1.3. Also note that ASME VIII Div 1 is the bible for pressure testing of pressure vessels - 1.3 X maximum allowable working pressure. I've never heard of testing by volume change - it is by pressure loss or leak. "Rejection Elastic Expansion" shows a clear lack of knowledge of "permanent deformation". Elastic Expansion means it will return to its original shape. Any rejection would have to be to "Inelastic Expansion", although I have never heard of this criteria.