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Post by builder01 on Oct 9, 2020 10:10:18 GMT
If you are concerned about the Viton balls floating, just drop one in a cup of water and see what happens. Mine are very dense and sink right to the bottom when I gave them the water test. Even if they did float, they should be captured close enough to the seat that the water flow should force them into place. There is probably something else going on.
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Post by builder01 on Sept 19, 2020 17:31:28 GMT
I would guess that setting any plastic or rubber on fire would release gas that would not be good for you. Other than the coal, do not set your loco on fire!
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Post by builder01 on Sept 19, 2020 15:50:40 GMT
Yes, my straps and "hinge tubes" are made from one solid piece. In the photo, I have not rounded or shaped anything. You can shape the tubes after to make them look more round.
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Post by builder01 on Sept 19, 2020 15:35:42 GMT
I did a little research on Viton, and it is true that the older types of Viton are not recommended for hot water or steam. The newer types have excellent qualities for use with steam. This is probably why McMaster-Carr lists Viton as good for use with steam as they are selling the most recent type of Viton balls.
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Post by builder01 on Sept 19, 2020 15:22:42 GMT
If Viton should not be used for steam, I don't understand why the McMaster-Carr says it's okay. At any rate, there should only be cold water in an axle pump or hand pump.
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Post by builder01 on Sept 19, 2020 14:36:34 GMT
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Post by builder01 on Sept 19, 2020 12:43:37 GMT
Mine are not viton, but nitrile from maccmodels.co.uk There is a thread here on another forum about this subject that might be of interest....see references to seat design & ball sizes etc. Cheers Don Nitrile, or, Buna-N will work okay, but, Viton has a much higher temperature specification.
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Post by builder01 on Sept 18, 2020 23:04:03 GMT
I get my Viton balls from McMaster-Carr, a supplier in the U.S. I am sure there is someplace in the U.K. that can supply them. They are not exactly cheap, they are usually sold by the "each". The good news is that they work and can be an exact replacement for a stainless ball. I replaced all the stainless balls in my hand pump and axle pump and have never looked back. The one in my injector clack has alowed my injector to work 100% of the time. The slightest leak here, and the injector will heat up and become useless. Because the injector clack ball really takes abuse from the heat an pressure, I replace it very year and it always works.
One place that I had to keep stainless balls is in my steam operated feed water pump. The balls are, of course, on the clacks on the water side of the pump. The pressure delivered by this little positive displacement pump can be quite high. If these balls are "elastic" in any way, you might force a ball past it's seat! Don't ask me how I know! Also, a little leak with a metal ball here is not a problem in this instance. I have never had a ball stick in the pump, maybe they break free when it starts up, I don't really know. It just works!
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Post by builder01 on Sept 18, 2020 22:38:22 GMT
So, if the metal ball is not on the metal seat when the water evaporates, where does the lime scale go? Is is evenly distributed all over the inside of the valve and the outside of the ball? It seems like the lime scale will still be there if the ball is on the seat or not. Will the ball be able to re-seat with lime scale on the seat?
I use hard viton balls in both my hand pump and axle pump. These seal even if the seat is not perfect as they are slightly elastic, they seem to not stick either. I also use a viton ball on the clack between the injector and the boiler.
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Post by builder01 on Sept 18, 2020 2:17:43 GMT
Here's how I did it. Quick and effective. The hinge bracket and hinge straps can be shaped more if you feel the need. These are all made from stainless steel. Nothing soldered, all fastened with screws. DSCN1395 by Builder16, on Flickr
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Post by builder01 on Sept 17, 2020 20:05:25 GMT
For me, it is certainly the destination, not the journey. I find running my loco much more satisfying than building it. In fact, building is rather tedious and sometime quite boring for me. I got my loco running under it's own steam in 23 months, another 18 to finish the plate work. It would have taken less time for the plate work if I had taken some of my steaming time to do it! I steam my loco as often as I can. The winter closes down my club track and it seems like an eternity to get back to running!
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Post by builder01 on Sept 17, 2020 13:40:08 GMT
The folks that seem to take forever, or never finish a loco, always seem to say "it's the journey, not the destination".
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Post by builder01 on Sept 3, 2020 12:27:24 GMT
So, for all practical purposes, nitrile does last forever. I've got 'O' rings that are decades old in my stock, and they're just the same as they were when they were made as far as I can tell. Actually, nitrile O rings have a shelf life of 15 years, they do not last forever. Like any natural product, they will degrade. Shelf life of Viton and FLAS is infinite. So, if you have decades old nitrile O rings, you may want to toss them. This is from www.oringsusa.com/html/shelf_life.html
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Post by builder01 on Sept 2, 2020 22:31:44 GMT
I wonder where the little piece of O ring will go when it breaks off after a few thousand cycles? Why do you think it will break? The displacement is only about 0.2mm and Nitrile doesn't suffer from fatigue as far as I can tell, and is impervious to water. What's the failure mechanism you're worried about? I think it will break because of what it is made of. There must be a finite number of cycles that can happen before it breaks. Time will tell. Is there much track record of folks using a piece of an O ring for a spring? Does it simply last forever? I'm just thinking what will happen in the long run as I always consider a material like this as a consumable.
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Post by builder01 on Sept 1, 2020 23:54:53 GMT
Can I point you to my idea of simply modifying the inlet valves on hand and axle pumps so that a little piece of 'O' ring (or a very light spring) lifts the ball very slightly off the seat? That way, they can never get stuck! It's such a simple solution, I'm staggered that it wasn't thought of years ago and implemented universally since this is a recurrent theme. I wonder where the little piece of O ring will go when it breaks off after a few thousand cycles?
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Post by builder01 on Sept 1, 2020 11:57:28 GMT
I put my hand pump axle pump in series solely for the purpose of being able to prime the axle pump. For me, stuck check balls has not ever been an issue, but, a simple way to free them would be a bonus.
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Post by builder01 on Sept 1, 2020 0:23:21 GMT
Greetings, for many years, I have used the hand pump in series with the axle pump, feeding in to one clack. If you suffer from "stuck balls", a few stokes of the hand pump will clear them. In use the axle pump sucks water through the hand pump, lifting the valves, and keeping them clean. regards Brian This is exactly how I have my hand pump and axle pump piped. It works quite well. I use the hand pump to prime the axle pump. They are in series and both feed into the same boiler clack. This scheme was suggested to me by a friend with much more experience than I.
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Post by builder01 on Jun 23, 2020 10:06:57 GMT
Thank you for taking the time to learn about adding the images. Things look great! I wish all of the build threads posted had images included instead of just a link.
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Post by builder01 on Jun 19, 2020 10:57:56 GMT
I wonder why this was posted in the general chat for Simplex?? I think I may have selected the wrong "General Chat" perhaps ??.............in any event it wasn't intentional... Okay, I understand.
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Post by builder01 on Jun 19, 2020 1:18:54 GMT
Where else? Well, probably in the main General Chat area versus the specific general chat area dedicated to Simplex. The video will get many more views if posted in the main General Chat area. Great video, but, a bit hidden here.
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