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Post by Roger on Dec 5, 2020 8:15:33 GMT
Hi Roger, re the boiler treatment...I just had a quick look at the link Chris posted.....Looks like TS is the one for you as it would seem to be spec'd for steel. I love the way of figuring out if you a short, just right or over dosed....short the sightglass will be lager coloured, just right bitter ale, too much Guinness!! Its going to be real tough having to open bottles of beer to use as a colour reference, I mean what to do with an open bottle...guess you'll figure that out! They also recommend blowing the boiler down & storing dry if out of service for awhile On the water front...do you have a dehumidifier or as we have just got a condensing clothes drier, both are a great source of soft water I hope you don't have Elves in your shop those reamers would make great javelins! Cheers Kerrin Hi Kerrin, I'll have to get some of that on order. That's a clever way of checking the dosage, although I'm not a drinker of any kind, so those bottles can stay closed. I don't have a dehumidifier, but I do have some Distilled water, so that might be worth using. I'll watch out for Elves!
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Post by Roger on Dec 5, 2020 9:21:13 GMT
Hi Malcolm beat me to it. There are two issues, one is that in this day and age a pressure gauge not designed for steam could have plastic parts in it which might not like the temperature. The other, which would apply to most gauges, is that thermal expansion of the bourdon tube will give you an inaccurate reading. I would use a siphon tube personally. Regards Paul But isn’t the steam at the same temperature as the water anyway, more or less? Until in the absence of a syphon, it arrives at somewhere cooler (like the inside of the Bourdon tube) where it condenses anyway?? Just asking... Gary Hi Gary, I too wonder how hot the gauge will actually get. My guess is it won't matter much anyway. I can see that if you have a decent length of pipe then it makes sense to put the 'U' shape such that the water doesn't collect in the gauge. How much difference it would make being full of water or empty is open to debate. It's the length of pipe that insulates it mostly from the heat in my opinion. Anyway, I'm not overly bothered about it, I think it will be fine until proven otherwise. I can change it if there's a problem. For the moment it's just convenient to attach the gauge like that.
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Post by delaplume on Dec 5, 2020 10:42:45 GMT
Hello all,
Three books that I used for reference when designing my Great Bear boiler which might be of interest}--------
1) "The Design, Construction, and Working of LOCOMOTIVE BOILERS"..... an engineering appraisal by Alan J. Haigh, C.Eng M.I.Mech.E." and published by}--Xpress Publishing... ISBN 978-1-901056-39-6
2) "Maintenance of Locomotive Boilers"...by Allan Garraway via The Heritage Railway Association = ISBN 0-7110-2746-3
3) "Model Locomotive Boilers" by Martin Evans....Published by MAP Technical Publication........ ( Pre--ISBN )
Alan
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mbrown
Elder Statesman
Posts: 1,765
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Post by mbrown on Dec 5, 2020 13:22:20 GMT
The water in the syphon will be condensed steam, and being static in a small tube, the temperature drop between the boiler and the gauge would be quite considerable - water being a poor conductor of heat.
On a "full size" narrow gauge loco, I can keep my hand on the gauge end of the pressure gauge syphon tube when at full boiler pressure, but other stem pipes would give me a nasty burn (I have the scars..)
Malcolm
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Post by Roger on Dec 5, 2020 18:05:01 GMT
The water in the syphon will be condensed steam, and being static in a small tube, the temperature drop between the boiler and the gauge would be quite considerable - water being a poor conductor of heat. On a "full size" narrow gauge loco, I can keep my hand on the gauge end of the pressure gauge syphon tube when at full boiler pressure, but other stem pipes would give me a nasty burn (I have the scars..) Malcolm Hi Malcolm, Surely the reason you get burnt on the other ones is that there's flow through them? It would be interesting to see how hot the gauge would be if the syphon wasn't there.
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mbrown
Elder Statesman
Posts: 1,765
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Post by mbrown on Dec 5, 2020 19:24:44 GMT
It is actually surprising how hot steam pipes get even when there is no flow through them - for instance, injector steam pipes when the injector is off.
But the only way to tell is experiment and I am sure you'll find the answer!
Malcolm
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Post by Roger on Dec 5, 2020 22:28:25 GMT
This is the setup for getting the Stop Collar in the right place on the reamer. The RH piece has a 1.6mm reamed gauge hole in it. The coller and the gauge piece were held against the 14mm Slip Gauge while I slid the reamer in until it stopped. There's an M2.5 grub screw locking the collar in place. So now I know precisely where the 1.6mm cross section lies relative to the face of the stop. Using the CAD model, it's a simple matter to draw where the 1.6mm section is and find the distance that is from the end of the cone body. As it happens, it's below the surface on the Condensing Cone end and above the surface on the Delivery Cone end. All that's required to set it up on the Lathe is to use a 25mm Slip gauge between the end of the Cone and the Stop Collar to set the Tailstock DRO to zero. Once that's been done, the depth is 25-14 plus the depth for the Condensing end and 25-14 minus the depth for the Delivery end. 20201205_132118 by Roger Froud, on Flickr I'm going to need a way to hold the cones in the Lathe while I ream the holes after drilling the cross holes. That's what this split sleeve is for, it will just protect the narrow lands of the O-ring lands from being damaged by the chuck jaws. 20201205_220226 by Roger Froud, on Flickr 20201205_220837 by Roger Froud, on Flickr This is the bottom half of the control box which is in ColorFabb HT which is good for well over 100C working temperature. If it gets hotter than that, we really have a problem. This was paused near the end of the print for four hex nuts to be dropped into pockets before resuming. This is such an easy and convenient way to add metal threads to parts. 20201205_103336 by Roger Froud, on Flickr Ok, the finish isn't exactly great, I think the bed needs a bit more of a clean than I gave it. Still, it's plenty good enough for what it is. 20201205_211256 by Roger Froud, on Flickr I've left plenty of room for air to flow around the circuit and to make it easier to wire up. There's no real size constraint so it seemed sensible to be generous with the dimensions. 20201205_222530 by Roger Froud, on Flickr
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Post by jon38r80 on Dec 6, 2020 13:27:59 GMT
Nice to be able to make your own project box to the size you want. Its always a pain trying to find a suitable ready made one, the dimensions are never quite right in at least one axis. The finish looks fine, the plastic ones you buy are never that brilliant unless you pay a lot, they have moulding ridges and edge flash that always need cleaning off. Painted cast metal ones always look good but the price makes them unattractive. I wondered what your material cost was against buying a commercial one of a similar size? thats if you could buy one in a suitable heat resistant plastic.
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Post by Roger on Dec 6, 2020 14:03:34 GMT
Nice to be able to make your own project box to the size you want. Its always a pain trying to find a suitable ready made one, the dimensions are never quite right in at least one axis. The finish looks fine, the plastic ones you buy are never that brilliant unless you pay a lot, they have moulding ridges and edge flash that always need cleaning off. Painted cast metal ones always look good but the price makes them unattractive. I wondered what your material cost was against buying a commercial one of a similar size? thats if you could buy one in a suitable heat resistant plastic. Hi Jon, I know exactly what you mean, they're never the size you want. The cost works out to about £4 in this material. Most reels cost around £30, and that goes a long way because most things aren't solid.
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Post by Roger on Dec 6, 2020 21:18:54 GMT
This is the element cover to stop me getting electrocuted and secure the cables. 20201206_090512 by Roger Froud, on Flickr The end doesn't really need to be hexagonal, but it provides a more robust end and it's trivial to do, so why not. The centre post reaches to the face of the threaded boss on the element so when the thread is tightened it doesn't try to pull the end of the cover out of shape. 20201206_090542 by Roger Froud, on Flickr It's probably longer than it needs to be, but it will make wiring it up and assembling it easier. 20201206_090644 by Roger Froud, on Flickr The two holes are printed M12, they just need a tap running through them to tidy them up. I've got the glands on order. It's a really nice fit on the face of the element, and I happened to have a piece of M4 threaded rod that was just long enough. 20201206_154348 by Roger Froud, on Flickr You can see from this shot of the element that the terminals stand out a fair way, and the crimps are pretty long too. 20201105_213409 by Roger Froud, on Flickr I realised that the large glands I've got for the control box were missing the lock nuts, so I've 3D printed two of those. They're Pg9 size which I happen to have a tap for, which is handy because they were a bit tight. Heaven knows why we need yet another 'standard' for conduits when a Metric diameter, form and pitch would have been perfectly satisfactory. This could easily have been M15 x 1.5 (fine) which is already a preferred size. 20201206_205326 by Roger Froud, on Flickr
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Post by andyhigham on Dec 6, 2020 21:38:20 GMT
PG is the German standard. Every one else (except the USA) use metric 1.5mm pitch
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Post by chris vine on Dec 6, 2020 21:39:20 GMT
Hi Roger and others, Re steam pipes getting hot.
The trouble with steam is that it condenses. So, even if there is a dead end to a pipe which is connected to a boiler then steam will go up the pipe, condense on the (slightly) cooler pipe a few inches from the boiler, and then the condensate runs back down the pipe to be replaced by more (hot) steam.
This is why there is such a high rate of heat transfer. if it was just a gas, then it would be a different kettle of fish!
The siphon means that some water gets trapped and essentially blocks this flow and return of steam and returning water.
If you don't believe this, then try shutting off the top valve on a water gauge when it is in steam. The water level almost immediately rises to the top of the glass as the steam condenses. A restriction in the top passage on a water gauge can cause a false high reading. I don't know how small the restriction needs to be, so maybe an experiment for me next time Bongo is in steam...
Chris.
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Post by Doug on Dec 7, 2020 7:54:42 GMT
Hi roger the cover for the element, is that 3D print if so it will most likely melt as it goes all floppy at even slightest temperatures you may need to add an insulated gasket between the element body and the cover 👍🏻
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Post by Roger on Dec 7, 2020 9:05:08 GMT
Hi roger the cover for the element, is that 3D print if so it will most likely melt as it goes all floppy at even slightest temperatures you may need to add an insulated gasket between the element body and the cover 👍🏻 Hi Doug, I'm hoping it's not going to be a problem. The maximum boiler temperature is 166C, and the melting point of the plastic is 260C. You wouldn't get away with it using PLA, but I might just with PETG. I'll give it a try and see if I need to do anything. It's easy enough to print another one if its an issue.
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Gary L
Elder Statesman
Posts: 1,208
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Post by Gary L on Dec 8, 2020 12:38:50 GMT
I found this interesting photo in a book I am reading: 'Railway Nostalgia Around Warwickshire' by D Hibbs, published 1993. The photo (by the local paper) hasn't found its way onto the 1501 preservation society's website, but it shows that when the three 15xxs were sold to the NCB they were in pretty presentable condition (or at least 1509 was). It shows clearly that the safety valve cover was bare brass, not painted over. The top lamp bracket has been cut off short, but I don't suppose the NCB had any use for those. The BR logo has been removed or painted over, as might be expected. Interesting that the cast-iron smokebox number and shed plates have been removed but not the brass cabside number plate. Hope this is of interest Gary
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Post by Roger on Dec 8, 2020 16:39:27 GMT
I found this interesting photo in a book I am reading: 'Railway Nostalgia Around Warwickshire' by D Hibbs, published 1993. The photo (by the local paper) hasn't found its way onto the 1501 preservation society's website, but it shows that when the three 15xxs were sold to the NCB they were in pretty presentable condition (or at least 1509 was). It shows clearly that the safety valve cover was bare brass, not painted over. The top lamp bracket has been cut off short, but I don't suppose the NCB had any use for those. The BR logo has been removed or painted over, as might be expected. Interesting that the cast-iron smokebox number and shed plates have been removed but not the brass cabside number plate. Hope this is of interest Gary Thanks for that Gary, what a cracking photo. I've added that to the archive.
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mbrown
Elder Statesman
Posts: 1,765
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Post by mbrown on Dec 8, 2020 17:55:43 GMT
They have also removed the vacuum brake gear (or at least the external piping) and steam heat. Not needed at the NCB!
Malcolm
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Post by Roger on Dec 8, 2020 22:06:31 GMT
A few of the electrical parts arrived today, so this now has a plug and the wiring is complete with the exception of the two power connections to the element. I can't finish that until the high current Silicone wire arrives. The earth connection goes to a lug which will be attached with an M4 bolt to the boiler foot. 20201208_215919 by Roger Froud, on Flickr
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Gary L
Elder Statesman
Posts: 1,208
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Post by Gary L on Dec 8, 2020 22:57:07 GMT
They have also removed the vacuum brake gear (or at least the external piping) and steam heat. Not needed at the NCB! Malcolm So they have! And even more interesting, there are no visible scars on the buffer beam, so this loco has been specially ‘titivated’ for the new buyer! Gary
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Post by delaplume on Dec 8, 2020 23:21:19 GMT
Wasn't that also mentioned on their website ??............I seem to remember re-fitting those items was one of the first things that they had to do at the SVR... Great photo Gary---- not bad for a 1963 newspaper article, eh ??............The tractor shows "Sunter Bros." Heavy Haulage....Here's their history}- ---- tractors.fandom.com/wiki/Sunters ------ Sorry Roger---- back on-piste now...
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