S. VIII D.1 EXEMPTION FOR PNEUMATIC VESSEL

[matb]

MY DESIGNER SAYS THAT A CARBON STEEL TANK 1m3, 30" diam, 145 PSIG THAT HANDLES AIR AT 122°F IS NOT TO BE STAPMED BECAUSE IT'S CONSIDERED INTO THE EXEMPTIONS ON U-1 (C) (6)"a vessel for containing water under pressure, including those containing air, the compression of which serves only as a cushion, when none of the following limitations are exceeded:
(a)a design pressure of 300 psi;
(b)a design temperature of 210°F"

Is this correct? because the consideration is specifically describing water, and air only as a cushion.

 

[samuelliu]

No, it is not. No such terms U1(c)(6) available from the latest one.

 

[Scipio]

Actually it is still in the code, only it's listed now (I think since 1992) as U-1(c)(2)(f). I'm not sure you can interpret it to mean any air vessel, however, otherwise that 'serves only as a cushion' qualifier wouldn't be necessary. I know there's a couple code interpretations on the original paragraph, VIII-1-83-247 and VIII-1-86-13, which might clarify that. Unfortunately I don't have access to any interpretation prior to 1989.

 

[deanc]

It falls under ASME SecVIII Div 1. If they have a problem contact the jurisdiction of installation.