S & U Stamholder is asking:
Subject ASME I and ASME VIII div. 1: Definition of Fired Steam Boiler, Unfired Steam Boiler and Other vessel in which steam is generated

Which is the right definition of Unfired Steam Boiler as per ASME?
I found on Preamble of ASME I the following definition about Fired Steam Boiler:
“A pressure vessel in which steam is generated by the application of heat resulting from the combustion of fuel (solid, liquid, or gaseous) shall be classed as a fired steam boiler”
Then I found:
Unfired Pressure Vessels in which steam is generated shall be classed as Unfired Steam Boilers with the following exceptions…..
(b) “Vessels in which steam is generated by the use of heat resulting from operation of a processing system containing a number of pressure vessels such as used in the manufacture of chemical and petroleum products”
that means these a.m. Vessels under (b) are neither Unfired Steam Boiler nor Fired Steam Boiler.
The questions are:
1) Which is the right defintion of Unfired Steam Boiler?
2) Is it possible to design and manufacture a Fired Steam Boiler according to ASME VIII div. 1?

Any comment?
Mauro

Dear Mauro,

I am trying my best to attach the pages of a book that was written by Martin D-Bernstein on Section I, basically this book is commentry on Section I. But I do not know how to attach the pages with this reply, please guide me little.
Martin nicely explained on fired and unfired pressure vessels.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Further to my above answer, there is another book written by Muhammad A.Malik that is also commentry on Section I, this book also explains fired and unfired pressure vessels. I have found only two books of commentry on Section I.
Is there anybody who knows any other book of commentry on Section I?

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Well, I will start with my opinion as given by Mr. Robert (BOB) Shueler in 1998, when I passed the B endorsement training course at the NB.
If it produces heat for use outside to produce energy, it is a boiler
If heat comes from combustion it is a power boiler (S).
If heat is recovered from process it is an unfired boiler (U)
Mauro

Dear Mauro,
You said
" Is it possible to design and manufacture a Fired Steam Boiler according to ASME VIII div. 1? "
I would say No, Section I would be the right choice because of following logical reasoning:

1- Section I understands the fired pressure surfaces in a better way than Divsion 1 for example PW-11 decides about required volumetric examination of butt welds by considering the part contains mixture of water or steam? or it contains only water? or it contains only steam? Then PW-11 considers whether part subject to furnace radiant heat or not? while UW-2(c) has no idea of these factors.
2- You cannot use SA-36 for the pressure parts in Section I except for stay rods but Divsion 1 permits its use for pressure parts with some limitations as laid down in UCS-(6)(b)(3).
3- Section I has special provisions for once-through boilers but Div-1 has no such provisions.
4- Section I has special provision for water wetted surfaces as laid down in PG-9 and PG-5.5 but Section VIII does not have.

There are many other logical examples that reflect that fired vessels are understood by Section I in a better way than Div-1.
So I would say No. Please also see Code Case 1855.

_________________
Thanks & Regards,
Nasir
Welding Engineer
DESCON Engineering Limited.
Lahore, Pakistan.
Mobile # 0092-336-4145402

Thanks Nasir. You are "bursting an open door" with me. The problem is that apparently the same user wants to bend the rules and keep costs as low as possible. (Note that item would be "generally constructed to ASME, no stamp applied") Therefore the manufacturer is wandering whether or not a Boiler may be constructed to a more relaxed requirements e.g. described as:

U-1(h) Pressure vessels or parts subject to direct firing
from the combustion of fuel (solid, liquid, or gaseous),
which are not within the scope of Sections I, III, or IV
may be constructed in accordance with the rules of this
Division [see UW-2(d)].

A boiler is within the scope of Sect.I therefore the above doesn't apply, But: what is a boiler and what is not?
After having heard all those caveat I ended the discussion saying that it will be the Safety Administration to establish it.
Mauro