Got boiler: questions about fittings and dents

[lancelot]

Hello Ron,
the cylinder bore is 1 1/8'', but it is Not slide valve , it will be of Corliss rotary valve type, two inlet at top of cylinder and two exhaust at bottom, so never having built this design before not too sure how much steam it will take to drive it...
All the best for now,
John.

[ron]

Hi John
I don't know much about Corliss valves [ie nothing] but I'm assuming they just let steam in and out the cylinder just like any other system so if your engine is 1 1/8" bore and single cylinder I think the 504 should run it?
This has given me an idea, I've run the Simplex on air, each side independently, once it's all built back up I think I'll see if I can run it off the 504, even if it's just short runs.
Ron

[jamespetts]

On insulation, I have been looking at the various options. Given that glass fibre is an irritant, I do not really want to have to tease it out by hand. MJ Engineering sell kaowool sheets - would that, sandwiched between, on the outside, the original boiler walls, and, on the inside, stainless steel sheets (with holes drilled for the screws) suffice to keep the heat in? Would it also be a good idea to improve the efficiency by strapping kaowool sheeting to the exposed top of the boiler using brass boiler bands, then painting the kaowool sheeting the same exhaust manifold black as the cast iron parts?

As ever, thank you all very much for your help, which is much appreciated.

Edit: One other thing - my father bought some glass fibre tissue, but I'm not sure that that's the right sort of thing. Would that work?

Edit: And something else: the instruction leaflet describes a "bush" to enable exhaust to be ventilated up the chimney, but I cannot see anything like that. How would one go about setting up that arrangement in a 504?

[ron]

Hi James
Looks like you're on your own with the insulation, the original asbestos millboard sheets struggle a bit [going by the temp the sides of mine get to anyway!] I would have thought modern alternatives would probably work better. Let us know what you find out.
I insulated the top of the boiler with hardwood strips held by brass bands, this improves the efficiency a bit but probably not as much as proper insulation would, makes it a bit safer and more to the point looks the part.
If you look underneath the casting, directly below the chimney you will see a boss cast on it, this needs to be drilled and tapped to take an adapter, feeding the exhaust up the chimney doesn't have a great deal of effect with gas firing but it does increase the efficiency slightly, never tried it with spirit firing but I would have thought it would have had a greater effect. It does look the part with the exhaust going up the lum
Here is a picture of the 504 with hardwood strips fitted, the pressure gauge fitting is a home made compact one rather than the usual U tube.

[jamespetts]

Ron,

thank you: very useful information and photograph. Your boiler does look lovely with all that wood, although I expect that it took you some time to cut all the wood to the right size and varnish it all.

I think that I will try using kaowool or fibreglass for insulation both of the firebox and of the boiler top. I notice how you have done your brass bands (presumably with a nut on the other side of the screws into the top of those steel walls), and will take that on board.

Presumably, the asbestos was not very good insulation because asbestos is not really meant as insulating material, more fire retardant. Perhaps kaowool/fibreglass will make the boiler more efficient?

[dickdastardly40]

Hi All,

Is efficiency the reason for insulation on a model boiler or is it more for safety? ie a very hot radiant item with no other means of stopping fingers getting burned. Asbestos would be very good at that I'd imagine.

I understand that if Asbestos is encapsulated and not disturbed it is no more dangerous than anything else, though I'm happy to be put right on this issue if it is not the case.

Interested in other members views.

Al

[jamespetts]

dickdastardly40 said:

Is efficiency the reason for insulation on a model boiler or is it more for safety? ie a very hot radiant item with no other means of stopping fingers getting burned. Asbestos would be very good at that I'd imagine.

I've been told that it's for both, although, as you might have gathered, I'm rather new to all this, so I might be wrong. I'm certainly wanting to increase efficiency by insulation. My understanding is that it works. It's fairly self-evident (unless I'm terribly confused) that insulating will reduce (but not, unless the insulation is very good, eliminate) the risk of burning, I think :-)

I understand that if Asbestos is encapsulated and not disturbed it is no more dangerous than anything else, though I'm happy to be put right on this issue if it is not the case.

The problem with encapsulation is: (1) the thing that it's being encapsulated in also needs to be fireproof, or else it is of limited use (here, at least); and (2) encapsulation is not infallible: if anything happens to the thing that's encapsulating it, even general wear and tear, the dangerous fibres can get out: it's just too dangerous even when encapsulated. Encapsulation is only advocated for existing asbestos in buildings because removing it can create so much dust that it's often safer to keep it in place, encapsulated, than it is to remove it.

[Jo]

Boiler cladding: Has anyone noticed those very nice hard wood stirrers that seem to be appearing at certain cafes? The only problem with them seems to be successfully acquiring a good fist full (sufficient to do the whole boiler) without getting looks of disapproval.. . Sometimes you even have to buy a second cup of coffee to get enough .

John: I very much doubt that a 504 would run your Corliss for long! I was considering taking a feed off of my Clayton boiler for mine.

Jo

[lancelot]

Hello folks,
just received my 504 Stuart Babcock boiler...looks to be in very good nick...complete with all fittings and spirit burner...the interior is lined with about 1/8'' ASB/board (more later)
waiting on the sight glass to come...
Spoke to Stuart Turner R/E interior fire proofing (ASB.), he suggested, if not happy a substitute (ASB) free board abou 1/4'' thick could be obtained from builders suppliers... S/T can supply fittings and lagging for outside surface of boiler, but quite pricey...I would be happy with sheet fibre glass to do the job.
I did not get much help with obtaining the fitting sizes (outlet valve on top of boiler and clack valve at front below pressure guage) S/T can supply Aluminum washers for fittings, any reason why annealed copper washers may not be used.
Daft Question Time,
I am right in saying that the piping is... water feed via the clack valve below pressure gauge, steam outlet via the valve on top of boiler?
All the best for now,
John.

[ron]

Hi John, your piping is correct, steam outlet via valve on top and water inlet via a clack on the rear.
Don't take this as gospel but I'm pretty sure the fittings are as follows, steam outlet, inlet clack and safety valve 5/16"X32, gauge glass and pressure gauge fittings 1/4"X 32. This is a bit of a nuisance as it is easier to get small fittings with a X40 thread.
I would use either annealed copper or fibre washers, the aluminium ones, although handy for spacing, degenerate with time and cause problems.
Ron

[lancelot]

Thanks for that Ron, I do not want to move any fittings until I get the sight glass fitted and warm the boiler up a bit...scared to move any of the bits when cold in case they shear off...if I have read your post correctly, you are giving me the thread sizes for fittings to boiler (correct) ?...it is the pipe connection sizes to the fittings which I need i/e steam outlet (which looks1/4''pipe) and the pipe connection to the ''clack valve'' which is smaller as the nut for the steam outlet valve just slides over the thread...Maybe 504 boilers can vary with fittings, I do not know, seemingly neither does S&T...I think I will go with the annealed copper washers, sounds right.
All the best for now,
John.

[ron]

Hi John
On mine both the inlet clack and the steam valve are threaded 3/8"X32 to take a nut and olive to suit 3/16" pipe, that's the original ST fittings, although you could make an olive to suit 5/32" pipe if you wanted.
Ron

[lancelot]

Thanks Ron, looks like I will have to do just that, why do I always pick the awkard ones ...are you going to set up a feed pump and reservoir to feed the boilerand if running more than one engine at once would you need to put a ''Condenser'' into the system? ... toying with the concept of using the ''TICH'' 3'' boiler as piggyback if I eventually get the Corliss built, I wonder if it would work...
All the best for now,
John.

[ron]

Hi John
I've got a feedpump and tank but you don't really need it unless you're going to fire the boiler with gas, spirit fired, fill the boiler to nearly the top of the glass and a fill of the spirit tank lasts till the boiler is at the bottom of the glass [about 20/30 min approx if I remember right running a ST Victoria].
If you use a feedpump you need to use hot water, cold water kills the steam pressure as soon as you start pumping.
With regards to condensers, feedheaters, tandem boilers etc, these are all used successfully in industrial boiler plant, it really comes down to how far you want to go [and how much you want to spend!]
As I said before I know nothing about Corliss valves but I would have thought if a 504 can drive an 1 1/2" ST slide valve engine I don't see why it can't drive a single cylinder 1 1/8" bore Corliss engine unless the Corliss system is very wasteful of steam? It will also drive the 1" bore Victoria with capacity to spare.
One thing I would add after having used a very large vertical boiler my pal owns, the bigger the boiler compared to the engine the easier the set up is to operate, also with these small engines the built quality has to be A1, the slightest tightness or binding and the boiler will struggle.
Ron

[jamespetts]

1. Heat proofing

I am not sure whether this is the best solution, but I have decided to go with kaowool from MJ Engineering. Their larger sized sheets seem to be just about the right size for the side panels - one each, and then another one to cover the top as lagging (Ron's photograph above seems to show quite clearly how to fix lagging to the boiler with brass bands (not the musical kind!), which can also be bought from MJ Engineering.

Do be very careful when disposing of the old asbestos liners - best remove them outdoors.

2. Piping sizes

The pipe size on the supplied main steam outlet wheel valve is 1/4". The check valve (I bought mine separately) which fits in the lower right hand fitting of the four end boiler fitting holes takes a 3/16" pipe. The 1/2" water ram pump from GLR Modelmaking Supplies has a 3/16" pipe fitting. I do not know what pipe fitting that the Stuart water feed pump takes.

It does matter which way around that the steam outlet and safety valve are, since the 504 comes with a superheater. The leaflet that came with mine explains that the middle pipe underneath the boiler is the superheater. That pipe is connected directly to the front outlet (the one nearest the water/pressure gauge fittings) so that is the outlet that into which the steam valve should be fitted, and the safety valve should be fitted to the back outlet, near the chimney.

3. Pipe olives

I was advised by a very experienced modelmaker at an exibition last month that it is dangerous to use pipe olives for high pressure steam. The 504 is rated for 60PSI, which is really very high pressure indeed: the "high pressure" steam of the Trevithick era condemned as dangerous by Watt was around 20PSI, less than half the 504's pressure. Most of the toy steam engine boilers run at no more than 20-30PSI (the safety valve on my Wilesco D16, for example, is set to blow at 25PSI).

For high pressure steam joins, I was advised to use silver soldered connexions, which, I am told, are substantially stronger than the base materials themselves.

4. Feed water

Ron is right about spirit firing: in the leaflet that came with mine (which was new old stock, not used), it said that the spirit burner will last for about 30 minutes, and cannot be refilled while being used or even while hot. I do not know whether there is any safe way (for example, with a check valve and feed pump) to feed the burner tank with additional methylated spirit whilst it is running. That being the case, there is not much point in having a feed pump to keep the boiler topped up with water if the boiler water will last just as long as the fuel.

With gas firing, of course, a feed pump/check valve arrangement is far more useful. Ron, whom I suspect has far more experience of these things than I do, writes that adding cold water "kills the steam pressure". The pamphlet that comes with my 504 suggests using the feed pump "little and often", which would minimise the effect, if not eradicate it. I do not know how badly that steam pressure would be affected by using the feed pump with cold water in this way.

The only other alternative is to heat the feed water somehow. I am not sure how one would best go about doing this; Ron, any ideas? Two possibilities that spring to my mind are: (1) putting a small ceramic gas burner underneath the feed water tank, and running it on a low setting; and (2) running the pipe between the feed pump and the water inlet valve through the firebox. I do not know how well that the last idea would work: it would, I imagine, create a sort of flash boiler inside the pipe: as soon as the pressure in the pipe would exceed the pressure in the boiler, the pressures of the two would equalise through steam from the pipe passing into the boiler through the check valve. However, the pipe may very well run dry, I imagine, in which case it might melt, although that might be avoided with sufficiently frequent use of the pump. Or am I getting something wrong somewhere? Are there any other good ways of preheating feed water?

Edit: It occurs to me that whether the pipe would act as a flash boiler and potentially run dry would depend on what side of the part that passes through the firebox the pump was located: if the pump was between the tank and the hot section of the pipe, then, since the pump would prevent water/steam returning down the pipe, it would indeed have the undesirable flash boiler effect. However, if the pump was located at the other end, between the hot section and the check valve, then, as soon as the water in the hot section started to heat, it would just convect and exchange with colder water in the feed tank (especially if the pipe went downwards from the tank to the hot section), warming the water in the feed tank, which would be a somewhat more satisfactory solution. Or have I got that wrong...?

Incidentally, Lancelot, what were you planning to run from your 504? :-)

[lancelot]

Hello all,
some immensely useful information, for which I thank you...the point of the position of safety valve and outlet valve is interesting as I have seen models with them located the other way round...I intend to run the 10v, the score and the james coombes from the 504... the reason for asking about the pump and reservoir is that I may at a later date convert to Gas burner.
All the best for now,
John.

[jamespetts]

Shall be interested in seeing any photographs of you running those engines from that boiler :-) Very best wishes for it all...

[ron]

Hi James
It is probably a matter of relative values but 65 psi is VERY low pressure steam, you will have no problems with olives either soft soldered or silver soldered provided that it's done properly. I have even used neoprene or silicon tubing held on with wire ties for temporary set ups without too much drama ie it only blew off once and it was easy enough to shut the valve and refit the pipe [asbestos fingers help!]
I think I might be causing a bit of confusion here, I should really call them pipe cones rather than olives, cones are solder fittings, olives are compression fittings.
In industrial/commercial steam plant high pressure steam is between 650 and 900 psi, that gets a bit more exciting if something blows!
You are correct about the safety valve/outlet valve positions if you have them the wrong way round you will get saturated steam rather than superheated steam, although calling it a superheater is a bit optimistic I think, I look on it more as a steam dryer.
I will be very interested in how effective the Kaowool is, because as I posted before the asbestos millboard is limited.
Ron
PS Just noticed your other thread about the gas burner, Forrest can supply all you need regarding jets, piping etc and give good advice, I bought a 5"X2" ceramic burner from them, if I remember right there was about a month's waiting time when I bought mine and I had to chase them up.

[lancelot]

Hello James,
you might want to investigate the possible health risk factors using your proposed insulating material...an Australian site has declared it as a potential hazardous material...

www.dfcceramics.com.au/images/msds-kaowool-blanket.pdf

(the letters in ''kaowool'' were in bold font so you might not be able to open site)
All the best for now,
John.

PS. it works...

[lancelot]

Hello folks,
in the process of sorting out the fittings and pipework to plumb this lot in to the boiler, just discovered that G.L.R.fittings and Stuart Turner bits DO NOT MIX >:(I am going to have to run up a few fittings by the look of it ...Stuarts new sight glass assembleys no longer have the drain cocks... used ''Spurleys'' Brians...method of lining the fittings for the glass, little room for error in alignment, broke one already , lucky I have a good supply...regarding the Asbestos lining, keeping it in situ but thinking of spraying it with black Exhaust manifold laquer? to stabilise any dust.
Not having run these engines yet on steam would I have to give each individual engine its own direct steam supply from the boiler or perhaps DAFT question could one run on the exhaust steam of the other?
P/S...Ron you mentioned ''an adaptor'' to run the exhaust gas up the chimney, please enlarge on...
Just off the phone with Stuarts who very kindly gave me the drawing dimensions for the correct pipe cone 1/4 pipe to the boiler main steam outlet valve ...completely different from other suppliers sizes.
All the best for now,
John.