[Steam-engine] lap seam boiler pressure

[Ken Majeski]

Lawrence.... I have No Problem whatsoever with using 4. Where the problem is 
is that they state on their website and even in the proposed New Rules that 
they use 5 and 6. After all what good is a SF of 5 or 6 on the barrel when 
the firebox is 4.

A couple years ago our inspectors said Minnesota used 5 and 6 and they were 
going to do the same. Just figure out what the MAWP would be if you used 6 
on stayed surfaces. It took a Lot of Effort on our part to get this 
clarified and straightened out. Finally your chief admitted they used the 
13800 figure or the SF of 4 which is almost the same....

Whatever SF you use it should either be the same or should be stated as 
cylindrical VS stayed surfaces.... Other people and states are looking at 
your regulations all the time and the 5 or 6 figure is simply misleading to 
say the least...

We Should be working to get all states the same but the way things are going 
we seem to be drifting farther apart...

Who ever heard of shutting the state services down because they can't agree 
on a budget???? Seems strange but it is happening over there now.... I geuss 
we should consider any boiler rules at all a Miracle... :)

Ken Majeski, Ellsworth Wis. Case Steam Engine,  Rumely Oilpulls H, F, & R. 
Website, Http://www.pressenter.com/~kmajeski/




>From: "Lawrence Swanz" <LSwanz at superioriron.com>
>Reply-To: Steam-engine mailing list 
><steam-engine at lists.stationary-engine.com>
>To: "Steam-engine mailing list" <steam-engine at lists.stationary-engine.com>
>Subject: RE: [Steam-engine] lap seam boiler pressure
>Date: Fri, 8 Jul 2005 11:29:30 -0500
>
>Ken,
>
>You stated, "Also I have issues with the Minnesota safety factor. They 
>state they use 5 for code or 6 for non code and they clearly use a SF of 4 
>on the stayed surfaces. That almost got us in trouble when the inspectors 
>were confiring a couple years ago...."; You may have a problem with 
>Minnesota using a factor of safety of 4 for stayed surfaces, or a hard 
>number of 13,800.  But this is a number, that until late, A.S.M.E. used in 
>the formula for figuring design for stayed surfaces.  A few years ago 
>however, A.S.M.E. changed this to 15,800 or roughly a factor of safety of 
>3.5.  So, for those who are building new boilers, the boiler industry is 
>and will be using the current A.S.M.E. formulas.  With this in mind, a 
>boiler designed for 150 lbs., assuming they lightened the boiler plate to 
>its thinnest material instead of the standard .375" thickness that we 
>hobbyist like to see; then it is possible for a brand new boiler to 
>automatically have a reduced pressure by the assumption!
>   that we should be using a factor of 5 for code boilers.  This is why I 
>believe Minnesota uses the 13,800 or factor 4 in its formula.  By the way, 
>does anyone know when the last boiler in Minnesota ruptured as a result of 
>thinning due to over pressurizing by utilizing this methodology in its 
>stayed surface formula? or any boiler in Minnesota for that matter?  I 
>believe in operating these relics safely, but I also believe in that if the 
>metal is there, then let it run, and if it isn't repair or replace.  But 
>don't over precaution, let's be realistic about it.
>
>Lawrence
>
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