Exact Legal Patchwork in the US for Boilers on Boats

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DetroiTug
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by DetroiTug » Wed Nov 01, 2017 7:48 pm

Quote: "And listen If you want to talk about my boat do it in the right venue, otherwise it just looks like an ad hominem attack."

Sorry if you took it that way.
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by barts » Wed Nov 01, 2017 9:40 pm

DetroiTug wrote:Quote: "And listen If you want to talk about my boat do it in the right venue, otherwise it just looks like an ad hominem attack."

Sorry if you took it that way.
Wouldn't this be a "ad naviculam"* attack :) ?

- Bart

* No idea how to correctly conjugate this; it needs to be in the accusative singular afaict.
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by cyberbadger » Wed Nov 01, 2017 10:05 pm

DetroiTug wrote:Sorry if you took it that way.
Apology accepted.

I apologize too if I upset anyone. Thing is I do care about safety and I think everybody reading this does too.

Getting into steam was a rough process for me, and I've see nearly the same thing happen again with new comers elsewhere and here. I have thought several times about making a 1-2min youtube video about steam safety and just point to all the good correct references/guides/law and basically a sum up of why there is no really such thing as a good cheap safe boiler without a far bit of effort, but point to some of the better options.

-CB
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by fredrosse » Thu Nov 02, 2017 5:40 pm

What has been addressed so far is the thermal expansion coefficients of the liquid and the containing metal. Our software for closed cooling systems considers the compressability of the fluid vs. pressure, in addition to its expansion due to temperature. To that add the expansion of the containing vessel due to temperature, plus the expansion of the container volume due to added stress as pressure climbs (or reduced stress as pressure decays). Some interesting results here, for many conditions pressure actually decreases as the system is heated, even though the fluid does expand in volume.
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by cyberbadger » Thu Nov 02, 2017 6:44 pm

Fred did you mean post that in a different thread?

This thread is concerning the laws concerning steamboating in the US, not the engineering.

-CB

P.S. Ok I see the full boiler sunshine post was in this thread.
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by barts » Thu Nov 02, 2017 6:47 pm

fredrosse wrote:What has been addressed so far is the thermal expansion coefficients of the liquid and the containing metal. Our software for closed cooling systems considers the compressability of the fluid vs. pressure, in addition to its expansion due to temperature. To that add the expansion of the containing vessel due to temperature, plus the expansion of the container volume due to added stress as pressure climbs (or reduced stress as pressure decays). Some interesting results here, for many conditions pressure actually decreases as the system is heated, even though the fluid does expand in volume.
This would suggest that the container volume increases more quickly than the fluid volume with temperature. Under what conditions does this occur?

- Bart
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by cyberbadger » Thu Nov 02, 2017 6:56 pm

barts wrote: This would suggest that the container volume increases more quickly than the fluid volume with temperature. Under what conditions does this occur?
Advection of the Earth towards Sol. The Boiler gets the heat first. Water can't swell before the boiler.

-CB
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by barts » Thu Nov 02, 2017 8:09 pm

cyberbadger wrote:
barts wrote: This would suggest that the container volume increases more quickly than the fluid volume with temperature. Under what conditions does this occur?
Advection of the Earth towards Sol. The Boiler gets the heat first. Water can't swell before the boiler.

-CB
Let's focus on steady state conditions; assuming something about heating (radiation/convection patterns) makes this too hard to think about.

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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by fredrosse » Fri Nov 03, 2017 1:21 am

CB is thinking transient conditions, where the heat gets to the metal, but not to the bulk of the water, that condition is rare, but might happen with some special circumstances.

The steady state / isothermal case is where the material of the piping and pressure vessel has a large thermal coefficient of expansion. PVC and CPVC have thermal expansion coefficients several times that of steel.

However, even steel containers can have more thermal expansion than several liquids. A good example is water, heated from 33F to 39F!
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Re: Exact Legal Patchwork in the US for Boilers on Boats

Post by cyberbadger » Fri Nov 03, 2017 5:02 am

fredrosse wrote: A good example is water, heated from 33F to 39F!
Do we get a fancy graph/simulation screenshot? That might look neat to see the relationship.

-CB
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