When to use ULT for vessel construction?

[JamesKerr]

Good morning,

We are looking to build a vessel made out of SA240-316L. The MDMT would be -320deg F at 165 PSI. The restrictions of ULT are "alternative rules" per the title of the section. Due to this title our engineering dept does not see the need to apply it to our vessel, they would construct to UHA only.

In what circumstance do the rules of ULT supersede the requirements found in UHA?

Is it the design engineer that determines if a vessel is subject to low temperature service?

Thank-you

 

James,
You would have better success posting this in the Boiler and PV Engineering section. There are some very experienced and knowledgeable people who can answer your questions.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."