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Author Topic: Jensen steam boiler explosion?  (Read 1821 times)

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Jensen steam boiler explosion?
« on: February 02, 2024, 01:46:00 pm »
Being new to this hobby and being very careful on safety I am just curious if anyone has witnessed or been apart of a model steam engine boiler explosion.    I know the jensen safety valves pop off at 25psi.      Not very much pressure if you ask me.   Can a jensen boiler blow up at 30 psi?  What is the maximum pressure one of these can explode?  I would certainly hope it's almost double or triple what the safety valve pops at.   


I hope I never find out but being curious in the hobby I am curious to know about it.
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Re: Jensen steam boiler explosion?
« Reply #1 on: February 02, 2024, 02:30:14 pm »
I don't have the image nor the specs at my fingertips, but I have seen a Jensen boiler that was supposed to have been tested to failure. It looked about like a football in shape and the pressures reached were in the hundreds of pounds if I recall correctly.

But then again, Jensen's are about the most overbuilt boilers in the toy steam field, while there are many others with thin walls, soft solders and long seams in their boilers that may well only be good to about twice their safety valve release pressures.

All that said, toy steam boiler explosions are historically, very rare indeed!
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Re: Jensen steam boiler explosion?
« Reply #2 on: February 02, 2024, 09:05:04 pm »
Quite right, Daniel. Tom Jensen Sr. hydro tested one of his boilers to 700 psi. It still didn't fail and he felt no need to press on as 700 psi was well more than enough. 

I have seen this boiler. It stretched a grew but no seam gave out. They still have it at Jensen and they will be happy to show it if you visit the factory.

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Re: Jensen steam boiler explosion?
« Reply #3 on: February 02, 2024, 11:53:38 pm »
I don't have the image nor the specs at my fingertips, but I have seen a Jensen boiler that was supposed to have been tested to failure. It looked about like a football in shape and the pressures reached were in the hundreds of pounds if I recall correctly.

But then again, Jensen's are about the most overbuilt boilers in the toy steam field, while there are many others with thin walls, soft solders and long seams in their boilers that may well only be good to about twice their safety valve release pressures.

All that said, toy steam boiler explosions are historically, very rare indeed!

 Jensen most over built toy steam boiler ?
 Ever seen a David Auld ? Toy steam boiler

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Re: Jensen steam boiler explosion?
« Reply #4 on: February 03, 2024, 08:48:21 am »
I don't have the image nor the specs at my fingertips, but I have seen a Jensen boiler that was supposed to have been tested to failure. It looked about like a football in shape and the pressures reached were in the hundreds of pounds if I recall correctly.

But then again, Jensen's are about the most overbuilt boilers in the toy steam field, while there are many others with thin walls, soft solders and long seams in their boilers that may well only be good to about twice their safety valve release pressures.

All that said, toy steam boiler explosions are historically, very rare indeed!

 Jensen most over built toy steam boiler ?
 Ever seen a David Auld ? Toy steam boiler

Yes Dennis .... Aulds certainly and Empires too, or for that matter Steamco's boilers seem pretty stout as well.

But I did use the modifier "about" in the phrasing of my statement!
"Information is not knowledge, Knowledge is not wisdom, Wisdom is not truth, Truth is not beauty, Beauty is not love, Love is not music: Music is THE BEST...   
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F. Zappa ... by way of Mary, the girl from the bus.

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Re: Jensen steam boiler explosion?
« Reply #5 on: February 03, 2024, 09:26:44 am »
I also think Empire's have very well made tanks, especially the pre-50s.
Richard

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Re: Jensen steam boiler explosion?
« Reply #6 on: February 03, 2024, 09:48:56 pm »
Ind-X also has a stout steel boiler that you could use for a semi tire chock if you wanted too. Provided it was properly drained after each use and not rotted out.
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Re: Jensen steam boiler explosion?
« Reply #7 on: February 04, 2024, 02:13:32 pm »
I was working on a horizontal Bing had tested it on air at 15 PSI on the regulator on my portable compressor, then did some construction work and turned the regulator up to around 100 PSI for nail gun. Came back to the Bing a couple days later and forgot to turn the regulator down, 100 PSI popped the seam in the bottom of the boiler. Decided to put a separate regulator on my bench after that.
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Re: Jensen steam boiler explosion?
« Reply #8 on: February 04, 2024, 02:54:36 pm »
Ouch!  I hope you were able to repair the Bing.  When I grow up I hope to have a Bing ;-)
Richard

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Re: Jensen steam boiler explosion?
« Reply #9 on: February 15, 2024, 01:45:14 am »
Somebody needs to do a hydrostatic test on an old boiler to “fail" pressure and give us some data. I hydrostatic test my wilesco’s to 80 psi that’s about 150% of operating pressure. Never popped one yet. I’ve never seen any data on failure pressure (probably a good thing too?)
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