SA-516-70 Steel

[nuche1973]

I have some information on SA-516-70 carbon steel and it looks comparable to structural A-36 steel. Am I correct in this assumption? I am checking a door design for a pressure vessel. The vessel is the SA-516-70 Steel but the door is A-36. The design temp is 500 deg F and +/- 6 psig.

 

[TGS4]

A-36 is not permitted for pressure vessel design in the ASME-world. You are correct that the two are plain carbon steels, but the similarity ends there. Look at the respective ASTM/ASME specifications for details.

 

[nuche1973]

TGS4,
I did notice that the temperature stresses were very similar. Is there a reason for the exclusion? (I am assuming that there is a tempering difference.) Does the ASME pressure vessel code address this? I have a copy of section 7 of the code. [I am acculuating some experience with pressure vessels through a client. Where I work the structure (shell, support legs, etc) of a pressure vessel is designed by the Structural department, hence my involvement.]

 

[gr2vessels]

Let me please bring in some light;- the ASME SA-36 is a permitted material for use in ASME VIII Div 1, as it is listed in ASME II Table D. The ASTM A-36 material may be used under the ASME BPV code, provided is certified for compliance withe ASME SA-36 specification.
However, CCB1 called his equipment pressure vessel, despite the mentioned design pressure of +/- 6 psig (???). Remember, the minimum pressure to qualify the vessel as pressure vessel is 15 psig, anything less is not covered by the BPV code ASME. Did you read the applicable design code on the vessel nameplate?

I assume that the mentioned door is some sort of quick opening access cover and is not welded on the shell. I also assume that the mentioned code (ASME Section 7) is in fact Section VIII for the design of the pressure vessels, not the guidelines for the boiler care (it sounded a bit scary that the shell of a pressure vessel is designed by the Structural department under ASME section 7).

As such, you can use the SA-36 plate, provided is correctly designed for the mentioned design conditions.
cheers,
gr2vessels

 

[nuche1973]

gr2vessels,
Thanks for the insight. I've often wondered why I got this particullar task/client and not our mech. dept. I just thought it one of those "low man on the totem pole" type things. I appologize, the copy of the code that I have is Section 8 and not Section 7. And you are correct in your assumption, the door is a quick access panel and not welded to the shell. Now, for one more question: what would be the correct term/nomenclature for the "structures" that I am dealing with? Our our client refers to these as "bin-vents/dust collectors/bag-houses/tanks/air cleaners". They are (structurally speaking) thin-plated cylinders (or the occasional box), in which air passes thru (creating pressure), and what-ever particulate in that air is collected via a series of suspended cloth tubes. Then the collected debris is dispenced into a hopper. I've been using the term dust collectors, because that's what they look like to me. Am I correct?

 

[jte]

ccb1-

SA-36 material may be used, but be sure the design is in compliance with Section VIII (that's Roman numerals there...) Div. 1 UCS-6.

Although the vessel is designed for only 6 psi, it is entirely permissible to design, build, and U stamp the critter in accordance with VIII Div. 1:

U-1(c)(2) Based on the Committee’s consideration, the following classes of vessels are not included in the scope of this Division; however, any pressure vessel which meets all the applicable requirements of this Division may be stamped with the Code U Symbol...

jt