Rectangular boiler design

[CBCMAN]

I am designing a rectangular boiler from a flat plate of steel. The steel will be bent to form the rectanglar shell of the vessel. Heads will be added later. My question is:
What is the correct section of SECTION I should I use (PG-46 or PG-27) in detemining the minimum thickness reguired?

 

[metengr]

What exactly are you fabricating? Is this the firebox enclosure for the boiler tubes or actual boiler setting (outside sheet metal to contain insulation/refractory) or is this a pressurized drum or header or what????

 

[CBCMAN]

This is an electric boiler "M" stamp, 100psi design pressure. Sides will be stayed.

 

[deanc]

Is this a heating boiler? Maybe Sec IV

 

[CBCMAN]

No, this is a Section I vessel. "M" stamp. Electric boiler.
Outside dim. 6" x 10" x 15" rectanglar shell 3/8" thk. SA-285C steel.

 

[metengr]

PG-46 in ASME Section I. The heads would be treated differently.

 

[deanc]

Suggestion:
1.Use a finer grain steel. ie:516 Gr70

2.Make your bends across the grain. Make sure you use the proper radius.

3.Be careful on your stays. Number,diameter,material,full pen.weld,etc.

 

[Jake600]

FYI,
You might want to check ASME Section VIII Div 1 as there are certain circumstances where an electric steam generator may be constructed under those rules.

 

[FredRosse]

CBCMAN, I have been looking to find SA 285C material for almost a year. Where can you get the stuff?

Thanks in advance for any info.

 

[CBCMAN]

FredRosse,
We purchase our SA-285C steel from a steel service center. Most of the time it is A-36 material that is recertified by an outside lab and tested to SA-285C specs. This is done by the sevice center and the cost is passed onto us in a higher cost per pound for the steel. Usually we pay about 4 cents/lb. more for SA-285C over SA-36. Depending on the amount of steel you need you can also order from a Mill (20 tons and up)
A starting place might be Ryerson Steel or CitiSteel.
Hope this helps!

 

[deanc]

CBCMAN:

Think you better review ALL of PG-10.