[Steam-engine] lap seam boiler preshure

[Ken Majeski]

Well....  Before I got my Undies all in a Bundle about rivet diameter or 
pitch I would find out exactly what your state is reguiring. And whether 
they are adopting NBIC Appendix C or just cooking up rules on their own. 
Many states are or have adopted the NBIC.

I do know that NBIC Appendix C is in the process of being rewritten. The 
last info I have is that they use a Joint efficiency of .74 for a double 
riveted lap.

Also if the design pressure of your boiler is 100 PSI WHY did you hydro it 
at 200 PSI. Here if they ever find out that you exceeded over 10% of 1 and 
1/2 times MAWP they CAN Condemn the boiler on the spot. NBIC appendix C only 
requires 1 1/4 times MAWP or at least working pressure if agreable to the 
inspector.

And YES the last Minnesota inspection I witnessed they used 1 1/4 MAWP. The 
minnesota inspector stated that use Adendix C.... I think they use whatever 
they fancy at the moment.

According to Appendix C the state can set any safety factor they want as 
long as it's not less than 4. Here we have to use 5 Unless we can Prove at 
least 55,000 tensil strength. And Yes... some people are cutting out chunks 
and having them tested so they can use a SF of 4.

Appendix C states they will assume a ts of 45,000 for wrought iron or 55,000 
for steel. The problem is in proving what you got.

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....



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




>From: CopperheadMarine at aol.com
>Reply-To: Steam-engine mailing list 
><steam-engine at lists.stationary-engine.com>
>To: steam-engine at lists.stationary-engine.com
>Subject: Re: [Steam-engine] lap seam boiler preshure
>Date: Thu, 7 Jul 2005 22:04:32 EDT
>
>Well'
>
>    The boiler had a 100lb. safety when I got it and I am assuming  that 
>that
>is design pressure I have hydroed it and it didn't leak at 200lbs. No  bad
>pits.
>
>No fusible plug or even a hand hole fore one.
>
>  Titusville boiler made for Fairbanks Morse.
>
>Lap seam double row of staggered rivets.
>
>safety is 800 lbs/hour @ 100 psi
>
>Not sure how to check the diameter of a rivet?
>
>Not sure how to get the tensile strength? Rockwell test?
>
>The boiler works good and has for years. hopefully the introduction of
>inspections here won't cause it to be unsafe?  I had a woman on the DHEC  
>board
>tell me once that even though we had had no incidence of hazardous waste  
>at our
>facility in 25 years that the introduction of the new hazardous waste  
>ruling
>would increase our chances that we would get some. I told her that if the  
>law
>would increase the risk then we should drop the law to reduce the risk. She
>looked up and to the left for a long time as she thought about that one!
>
>Chas F
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