Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[Tim Logan]

I am just getting familiar with steam. An RC boat always has a possibility of losing radio contact. In such case the engine continues to run. If the boiler runs out of water in that situation, you’ve lost the boiler. It would seem logical to always use a measured amount of fuel so that the fuel always runs out before the water - but use of a steam whistle could make that difficult. I’ve heard folks mention a cutoff valve. Is there an operating process or mechanical valve that can prevent boiler burnout if radio contact is lost? It’s a newbie question, but you have to start somewhere  ! Thank you in advance.
PS My steam plant is an MSM 3” [font=var(--font-heading-family)][size=calc(var(--font-heading-scale) * 3rem)]Vertical Boiler / Clyde engine[/size][/font]

[rhavrane]

Bonjour Tim,
Because of a missing RC safety gas valve, I finished to the hospital so now, all my boats have one, either made by friends or manufacturers.
Examples : https://youtu.be/y6b9mqO95Uk  https://youtu.be/mA6uC5dgoiM  https://youtu.be/zCgLBAxieNU
Manufacturer example : https://www.regner-dampftechnik.com/product-page/gashahn-rc-regelbar

[1967Brutus]

An RC boat always has a possibility of losing radio contact. In such case the engine continues to run. If the boiler runs out of water in that situation, you’ve lost the boiler.

I am told by knowledgable people, that you won't immediately lose the boiler since silver has a melting point of about 600 deg C (1100 F approx) and it is extremely unlikely that the burner is powerful enough to heat the boiler that high.
And to be honest, if I take a look at my own hobby burner and how much trouble it is to solder even much smaller items, I have no reason to doubt that.

A bigger issue is that many boilers are insulated by wood cladding, and that WILL start to char and is likely to catch fire if the situation lasts too long. That will probably also not cause loss of the boiler, rather loss of the entire boat.

So yes, a gas cut-off valve, or at the very least a valve that allows to regulate the burner back to minimum is very advisable.

Regner amongst others, sells a very nice item, very compact.
It has a mini servo so all you need to do is set the failsafe of your TX such that the valve closes at loss of signal and you're set.

[rhavrane]

Bonjour 1967Brutus,
I fully agree with you, I have forgotten to evoke the gas regulator accessory like the Microcosm P5 for example that I install on almost all my steam plants:
https://youtu.be/RHSrvRRYzNc

About burners, my 250/300 g/h ones are quite powerful and could damage the wood insulation and possibly the solders : https://youtu.be/TqcmQFQRClE

[1967Brutus]

Bonjour 1967Brutus,
I fully agree with you, I have forgotten to evoke the gas regulator accessory like the Microcosm P5 for example that I install on almost all my steam plants:
https://youtu.be/RHSrvRRYzNc

About burners, my 250/300 g/h ones are quite powerful and could damage the wood insulation and possibly the solders : https://youtu.be/TqcmQFQRClE

Please keep in mind, the Microcosm P5 will go to full fire at low pressure. When a boiler runs out of water, the pressure will drop to zero, causing the burner to go to full blast.

250 or 300 g/h burners are pretty powerful (represents a steam production of about 5 kg/hr, which is absolutely HUGE) , but I assume the boiler is equivalently larger as well, mitigating the problem somewhat.

[Tim Logan]

1967Brutus -
  Thank you so much for the help. Is this the valve you are referring to?
   [size=78%]https://www.gardenrailways.co.uk/regner-50810-rc-gas-tap.html[/size]

[1967Brutus]

Correct, that's the one...

[Tim Logan]

Perfect - thank you for the help!

[rhavrane]

Bonjour,
For information, I opened one of my gas valve which was leaking to identify the problem and solve it.
 https://youtu.be/YYaHkBzTGOI
 
Tight fit and dead O'ring 

[KBIO]

Hello !
I am told by knowledgable people, that you won't immediately lose the boiler since silver has a melting point of about 600 deg C (1100 F approx) and it is extremely unlikely that the burner is powerful enough to heat the boiler that high.
[/size]
[/size]This is a good point to talk [/size]about ! Are the burner we buy : Clevedon , M.Bayliss , Stuart , Miiature Steam and some others ; except Regner & Saïto ( made of brass ) are silver solder ???
[/size]I agree with Brutus that it is doubtful that a burner can melt a weld in our boilers. Having experienced the problem once, the boiler was reusable but the cladding and the isolation were gone. Was the integrity of the boiler suffered ? I Cann't tell !
[/size]Now , when I do my own burner , I never weld the furnace and boiler tubes in contact with the flare with silver , but CuPro (copper) . Any thing else is silver soldered.

[KBIO]

Hello !
I am told by knowledgable people, that you won't immediately lose the boiler since silver has a melting point of about 600 deg C (1100 F approx) and it is extremely unlikely that the burner is powerful enough to heat the boiler that high.
This is a good point to talk about ! Are the boilers we buy : Clevedon , M.Bayliss , Stuart , Minature Steam and some others ; except Regner & Saïto ( made of brass ) are silver solder ??? I doubt it  but maybe interesting to investigate.
I agree totally with Brutus that it is doubtful that a burner can melt a weld in our boilers. Having experienced running dry once, with a strong burner +/- 200g/h , the boiler was reusable but the cladding and the isolation were gone. Has the integrity of the boiler suffered ? I Cann't tell but I use it and there is no leak !
Now , when I build my own boiler , I never silver weld the furnace and boiler tubes in contact with the flare , but CuPro (copper) . Any thing else is silver soldered. And so far I Cann't complain ! Except when I miss a weld !
Does anyone has been heating dry and what was the consequences ??? 
Kind regards !

[ooyah/2]

Hi Yves,


I have build many Copper boilers for friends over the years and have never used anything but Silver Solder to all of my boilers and even if the flame of the burner hits a S/Solder joint and the boiler is empty, the joint has never remelted.
I use S/Solder from CUP ALLOYS 2mm dia and they have a melting  point  of 650- 730 C
If you are soldering the end plates or any other part and you wish to remelt and remove a part you require 3 x the heat to remove it, and this can cause problems.
Like wise if you are to add say a fitting after the boiler has been made you will not dislodge any other parts already S/Soldered.
You will however need to re hydraulic test the boiler or tank it before using.


Here are some samples of the boilers built over the years.
George

[KNO3]

To shut off gas in case of r/c signal loss you need more than just a valve actuated by a servo. You also need a programmable radio and receiver, so you can program the receiver to shut off the gas on its own in case of signal loss.

[1967Brutus]

To shut off gas in case of r/c signal loss you need more than just a valve actuated by a servo. You also need a programmable radio and re ceiver, so you can program the receiver to shut off the gas on its own in case of signal loss.

For safety reasons, I would use a solenoid valve, controlled by a simple RC-switch, and fed from the RX battery.
A wire breakage would render a servo useless, but would still cause the solenoid to close.