ASME Rated HW Storage Tank 1

[new2hvac]

I have a storage tank on a boiler loop that is no longer functioning and requires replacement. The existing tank is ASME rated. Question: under what circumstances do you require an ASME rated tank (and the premium pricing)?

I found some info that indicates an ASME rated tank is required when:
1) The tank volume exeeds 120 gallons.
2) The termperature exceeds 210 deg F.
3) The internal heat gain into the tank exceeds 200,000 BTUH

Of course, the storage tank should meet all of the above criteria and we can avoid the added expense. I was surprised to not see any pressure requirements on the list. Was it ommitted? Are there other items that have been ommitted?

Thanks!

 

[pipesnpumps]

ASME Section VIII (unfired pressure vessels) would cover this situation.

U1(c)2(f) states vessels containing water under pressure, including those using air as a cushion, are omitted from requiring a code stamp when none of the following limitations are exceeded:
-design pressure of 300 psi
-design temp of 210 F

(g) covers water heaters, and has the same limitations you listed, but the 200,000 Btu/hr is the heat input from the element or burner..

(h) says anything with a design pressure of <15 psig is exempt