SA 234 in firetube boiler - why not?
SA 234 in firetube boiler - why not?
(OP)
In Section II, A-234 grade WPB (being a carbon steel wrought short elbow) has an attached note G18. This note states that for Section I firetube boiler parts under external pressure, this fitting "may not" be used. My questions are:
1. Does this mean use of this material is prohibited under these circumstances, or is it left to the judgement of the designer?
2. What is the reason for this qualification (creep buckling maybe) ?
3. And where on earth would someone want to use a short elbow like this inside a firetube boiler?
Thanks in advance.
1. Does this mean use of this material is prohibited under these circumstances, or is it left to the judgement of the designer?
2. What is the reason for this qualification (creep buckling maybe) ?
3. And where on earth would someone want to use a short elbow like this inside a firetube boiler?
Thanks in advance.





RE: SA 234 in firetube boiler - why not?
If on earth you do not need it, well there is the answer.
May means you can under a variety of conditions. I do not know which ones.
ER
RE: SA 234 in firetube boiler - why not?
RE: SA 234 in firetube boiler - why not?
www.watercressline.co.uk/index.htm
Then go to the index,then to the"footplate courses" This should tell you how it all works.
RE: SA 234 in firetube boiler - why not?
Note for SA-234 that should be "internal" not external.
The English folks call the trottle valve a "regulator" which
may be more correct,depending on how you view it.
RE: SA 234 in firetube boiler - why not?
RE: SA 234 in firetube boiler - why not?
RE: SA 234 in firetube boiler - why not?
Here is a good start on your quest.
http://www.babcock.com/pgg/tt/steambook.html
RE: SA 234 in firetube boiler - why not?
of expectated less, so your fitting is out of range.
If you are allowed under sec VIII-1 unfired pv, you may be able to use it.
or why not forged steel?
'hope that helps. let us know.
ER
RE: SA 234 in firetube boiler - why not?
Your tips are greatly appreciated. Kind of supports my intuitive ideas about this. Since metal temps. are not high in my application, and since Sec VIII allows use of SA 234, I may go ahead with this in design. Thanks very much.
RE: SA 234 in firetube boiler - why not?
In response to your earlier question, this site may be of use (although it is for fired heaters, but engineering principles remain same):
www.heaterdesign.com
Hope this will help you. Regards.