Steel boilers

[Steve M. W]

Steel boilers

7¼ Sweet William. With a new steel boiler.

Do you leave it full of water with an additive if so what additive, or do you blow down while hot? or any other polite suggestions ;D

I have tried a search on past threads but got nothing regarding this question.

Many thanks

Steve

[Shawki Shlemon]

Shutting Down (extract from OZ code )
1- Dispose of the fire.
2- allow the boiler to cool until a pressure of 30 psi ,then blow boiler down through the blowdown valve/s .
3-For dry storage for short periods, remove a filling plug or other fitting immediately after blowing down,and leave the blowdown valve/s open to allow the residual heat in the boiler shell to dry the inside of the boiler.
4- For dry storage for extended periods , a boiler dried by the method above should be opened to allow a dessicant material to be placed inside,then sealed with all valves and fittings closed.
5-For wet storage, the boiler must be completely filled, ie, "water wedged" , with water containing a de-oxygenating compound .
6-Care should be taken in the movement of the engine fitted with axle pumps to ensure that the water remaining in feed pipes is not pumped into a bioler intended for dry storage .

[mike.rometer]

The Examination & Testing of Miniature Steam Boilers (New Edition 2006) which is the test code adopted by all of the organisations that handle the affairs of the hobby in the UK has the following tosay about this topic:

12.5 All boilers should be properly ‘laid up’ between steamings, this is of particular important for steel boilers where corrosion will continue during lay-up. It is recommended that boilers be laid up dry, completely drained of water, with blowdown valves open and an illuminated light bulb placed in the grate to provide a heat source.
‘Wet’ lay up should only be adopted for relatively short periods, when the boiler should be filled with water that has been boiled to drive off dissolved oxygen.


Mike Rometer

[Julia]

Steve
My experience is with miniature traction engines though I guess it is much the same.

A new steel boiler will take around 10 steamings to settle down during which time you will find that it is a lot more likely to prime. The object in these early days is to get the muck left over from manafacture out of the boiler so a good blow down to dry after each steaming is a good idea. Water treatment will make the boiler last longer but if you are blowing down each time it can work out expensive. It will also make the boiler more likely to prime. In my initial steamings I did not always use treatment.

A damp boiler rusts so you either have to leave it dry or full of de-oxignated water. Drying a steel boiler is not easy and takes time. Blowing down from warm may not get all the water out. When I lay my traction engine up for the winter I spend a day ensuring that the boiler is dry.

If I could find an easy way of drying the boiler I would never store the engine wet but I can't.

During the season I keep the boiler wet filled with treated water (501/502). At the end of a steaming I fill the boiler above the top nut of the glass. As the boiler cools form (120psi) the water shrinks and I can get more in.

Julia

[freddo]

G'day Steve

Not many people will believe this, but seeing is the best way of believeing.

Go down the pharmacy (chemist), buy some vitamin C tablets, put one in a jam-jar of water, and put another jam-jar of water beside it with no vitamin C. Stick a clean steel woodscrew in both jam-jars, put on the window-sill in the sun, and review in a couple of days.......

So - dissolve 5 vitamin C tablets in the water sufficient to totally fill (wedge) your steel boiler, and leave it for as long as you live - it will not corrode.

Roche (as they used to be called - what they are called now is nuts to me) had a huge glut of vitamin C. So they made it into a gel, and now in Oz and the UK, all steel box girders for bridges and the likes are injected with this vit-C gel to prevent corrosion.

Best anti-oxidant on the planet!

Freddo

Dunno much but I do know about this 'un.

[waggy]

Nice one Freddo!

How does this wonder of nature work?

Perhaps our good friend "the_viffer" can enlighten us?

Regards,

Waggy.

[freddo]

Just to clarify, Waggy - I'm talking about old fashioned ascorbic acid (vitamin C) tablets - 250mg. Not the flashy modern effervescent or "enriched with whatever" stuff that they try to promote to make extra dosh.

Freddo

[steam4ian]

G'day all.

I'm chewing a vitamin C tablet as I write. The pack says Sodium Ascorbate is the active ingredient and that it is an antioxidant and free radical scavenger. Don't blame me I'm only repeating what they claim!

However there does appear to be some science in Freddo's suggestion. Tannic acid is also claimed to be antioxidant etc and this is what is used in boiler treatment. Tannin works better in an alkaline environment. Part of tannin is Gallic acid which I remember being taught in High School chemistry removed oxygen.

It would not be surprising the ascorbic acid works, particularly is ferric (ferrous) ascorbate is insoluble.

When I am not sitting in front of the computer I must try the experiment.

At least chewing the vitamin c tablets I may wear out rather than rust out; i won't rust in peace. ;D

Regards,
Ian

[Noddy]

Gents,

Ethylene glycol mixed with the water prevents corrosion in IC coolant systems, with all the steel, ally, zinc and copper they contain.

I'm not suggesting that it is better than wattle bark, or vitamin C...

just readily available and presumably you can drain it out before you steam and re fill with the same batch after...

Keith

[wayne]

hi Julia

Removing moisture

on the closed circuit refrigerant dryers for compressed air after a repair we vaced the circuit down with a special pump, i am told this was to remove all moisture from the circuit and pump, prior to refilling with the refrigerant gas.

The pump is normally left overnight, they do work because if left on for too long they will pull the oil out of the refrigerant pumps crank case

[Steve M. W]

Thanks all for your replies informative as always, Julia have followed your progress over the years and tried to look for your experiences with your first steaming of Little Beasty but could not access your diary on the web is this because it is now available as a book?. The 4” Burrell is a traction engine I want to build but from the Live Steam Models drawings. Your fodens coming on well bar the hold up for Kits.
Freddo is it worth putting the tablets in while its in steam given that it will be blown down at the end of the day, its cheaper than an additive.
Once again many thanks
Steve

[arron]

Hi

For tong term storeage what about filling the boiler with an inert gas, such as the argon used in our mig welders?

Regards Arron

[Julia]

Steve
The Burrell stuff is still there. Just over a year ago I moved it to my "kitbuilder" webspace which would have invalidated any bookmarks stored on your computer. Incidentally I make no money from the sale of the book, the cost barely covers the cost of printing.

The account of my first steamings can still be found here:-

www.kitbuilder.co.uk/burrell/steaming1.htm

I have moved on a little since those earl days.

The novel ideas for preventing the rust are interesting but I am not sure they will work in my case. Some form of suction could be useful to get a flow of dry are through the boiler but I doubt if mine would hold a vacuum as it ain't designed for that. I have been using inert gas in my part full paint cans for years now and the basic idea works well to exclude oxygen - even a thin layer in the bottom of a can does not shin over. In the case of a boiler would it get oxygen out that is already desolved in the remaining water?

[Steve M. W]

Thanks for that Julia, I know there is no profit in your book we run a small print business so know the costs, all credit to you for making it available, you should get commision from Modelworks your site must be doing them some good especialy as they don't cover your detail on ther site. Well done and thanks for your help.

Steve

[freddo]

sw said:

Freddo is it worth putting the tablets in while its in steam given that it will be blown down at the end of the day, its cheaper than an additive.

Unfortuantely, Steve, vitamin C is "thermo-labile" - it breaks down if boiled.

Freddo