# PTFE Plug for Accucraft loco



## Chris Scott (Jan 2, 2008)

Could an Accucraft loco water filler plug be made from PTFE and work?

Could a Goodall ?


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## JEFF RUNGE (Jan 2, 2008)

Based on what I see here I don't think so. http://www.boedeker.com/teflon_p.htm


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## Chris Scott (Jan 2, 2008)

Jeff;
What spec is a problem? Boiler temperature isn't near PTFE operating temp of 500-600+ degrees F.


Looked a bit further; McMaster-Carr

Metric and English Threaded Rod; Materials;
Length tolerance: +/- 1.58mmMay also be available in Nylon, PVC, Polypropylene, 
Phenolic, PTFE, G10, Kel-FÂ®, Delrin/Acetal, Neoprene, Mylar, Glass-Filled Nylon, 
Peek, CPVC, ABS, PVDF / Kynar, Isoplast, Polycarbonate, Polyethylene, or UltemÂ® 

Metric Thread; 3, 4, 5, 6, 8 mm 
English Threads; 440, 632, 832, 1024, 1032, 1-8, 1/4-20, 5/16-1, 3/8-16, 1/2-13, 5/8-11, 3/4-10, 7/8-9



Would have to put a cap on the threaded rod. And I don't suppose the filler cap thread is whole number metric 5,0mm vs 5,5mm. 
So you would have to mill the cap, right?


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## Phippsburg Eric (Jan 10, 2008)

Chris-- 

I dont think the temperature or pressure are really a problem, but i don't think that the threads would hold reliably for any extended use. plastic threads do not have the holding power of metal threads. you could probably use a metal sleeve with the working threads internally threaded with course threads to hold the PTFE (Teflon) 

I think the ruby and such use a 10mm dia 1 thread/mm if memory serves.


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## Chris Scott (Jan 2, 2008)

Posted By Phippsburg Eric on 11 Aug 2013 07:24 PM 
Chris-- 

I dont think the temperature or pressure are really a problem, but i don't think that the threads would hold reliably for any extended use. plastic threads do not have the holding power of metal threads. you could probably use a metal sleeve with the working threads internally threaded with course threads to hold the PTFE (Teflon) 

I think the ruby and such use a 10mm dia 1 thread/mm if memory serves. 

Tapered thread ?

Loctite ?

Both ?


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## steveciambrone (Jan 2, 2008)

Why? 

Why do you want to use PTFE? Why not use the original brass one? 

Steve


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## JEFF RUNGE (Jan 2, 2008)

Chris, the opening statement under "GENERAL PROPERTIES" ":Mechanical properties of Teflon® are low compared to other plastics," This statement makes sounds like it may not be a good choice.


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## Chris Scott (Jan 2, 2008)

Posted By steveciambrone on 11 Aug 2013 08:37 PM 
Why? 

Why do you want to use PTFE? Why not use the original brass one? 

Steve 


I think the water fill plug can be made into a probe to detect both low and high water levels. Brass plug is too thick brass to drill small holes, or at least for experiments. PTFE first thing that came to mind. I can order a few plugs made for not much online. Just wanted to tap the brain trust here.


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## Greg Elmassian (Jan 3, 2008)

Ordinary plastic would not be strong enough, and teflon is softer, even less suitable. 

you can drill small holes in brass even thick brass. 

Greg


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## Charles (Jan 2, 2008)

Water fill plug would need to be durable in that if there is no other way to put water into the boiler it will be frequently removed. Given that brass would be better than plastic. Secondly, some fill plugs are not in the cab of locomotives. Lastly, how big will the probe be relative to the fill plug itself regarding "small" hole to drill?


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## Phippsburg Eric (Jan 10, 2008)

I think a teflon sleeve around a probe could be fitted to a brass plug and would be a very reasonable way to solve the problem. Perhaps even the best way! The stock plug is certainly big enough for a 3 or 4mm 1/8-5/32" drilled hole which could be big enough for a teflon sleeve on a 1/16" metal probe. the sleeve should be a press fit (with the probe in place into the drilled hole and should have a shoulder to prevent it from being extruded out of the plug by steam pressure.


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## Chris Scott (Jan 2, 2008)

Three methods for low/high water detector. First, and the one I'm going to try, uses three insulated wires. Second foto is using radar. I like the idea but like me it's impractical. Third foto is a float approach. Typically the float is a magnet. In Gauge 1 the float would be really small, again impractical. 


Eric; I can see another advantage to the PTFE plug in the brass cap. A lot easier to make vs machining the whole plug from PTFE. 

Thanks all for the suggestions. Keep ya'll posted. Chris



*Examples of Water Level Detection;*

*Closed/Open Circuit; *











*Radar Type *










*Float*


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## Bob in Mich (Mar 8, 2008)

Christ,I know that Last Sat was Your Birthday (Happy Birthday) But You are going out of control. 
Happy Steaming I hope to see You in Diamondhead 
Bob


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## Chris Scott (Jan 2, 2008)

Bob; 
You know how you can tell who your true friends are? They're the ones who remember your birthday, anyone else wouldn't dare. 
Thanks. 
Chris


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## Bob in Mich (Mar 8, 2008)

Chris,You will always be a Close and best frend,only a few people can say that.And they know who thay Are.Some in N.J.,Some in Pa.Some in Ohio,Lot in Michigan,Some in TEXAS,Some in Ara,And aLot in Sunnney Calf. To all My Great USMC Great frends God bless You all 
Regards and Happy Steaming 
Bob


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## lotsasteam (Jan 3, 2008)

How about using Acetal ? i do have a thermo injection unit ( 1 inch max diameter pattern) to make Flexite partials! If i can help out in in a pre machining casting let me know! 

Manfred


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## Pete Thornton (Jan 2, 2008)

Three methods for low/high water detector. 
Chris, 
I just got one of Bill Ford's WLDS and he doesn't use any ot those methods - so there are Four ! His system, as far as I can see, uses a probe in the water to conduct and inform the WLDS that there is a path. When the probe comes out of the water, even in steam, it doesn't conduct. You can test it using your finger's conductivity, so it doesn't use much power to see the circuit. 

And his probe is mounted in a brass bush with a teflon sleeve to insulate it. Would you like a photo - I don't think Bill is planning to make any more!


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## Greg Elmassian (Jan 3, 2008)

that's the first of 3 above


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## Chris Scott (Jan 2, 2008)

Posted By Pete Thornton on 13 Aug 2013 05:29 PM 
Three methods for low/high water detector. 
Chris, 
I just got one of Bill Ford's WLDS and he doesn't use any ot those methods - so there are Four ! His system, as far as I can see, uses a probe in the water to conduct and inform the WLDS that there is a path. When the probe comes out of the water, even in steam, it doesn't conduct. You can test it using your finger's conductivity, so it doesn't use much power to see the circuit. 

And his probe is mounted in a brass bush with a teflon sleeve to insulate it. Would you like a photo - I don't think Bill is planning to make any more! 
Posted By Greg Elmassian on 13 Aug 2013 09:37 PM 
that's the first of 3 above


I believe Bill's probe uses RF so it does have two elements. They seem to be encased in what I think is a cosmetic sheath for stealth. But I don't understand the mechanics of an RF design so that's a wild guess. The first foto above you can think of nakedly exposed elements or contacts. I don't see any reason they should need or have to be other than exposed. Maybe make them prettier if desired. 

Bill made three variations or models of his filler plug probe. I have two of them - I have not used them - one of those bench queen projects we all have a million of. All Bill's probes detects only low level not high water level. The 3 fotos posted are 3 methods and products for detecting low AND high water level; pump on pump off for our purposes. Bill's WLDS detects low water level only, turns pump on & red led. Pump is shut off via a timer. User sets the timer by trial and error experiments. Not an acceptable method/approach to my mind.

So there are 3 low/high methods (the 3 fotos above) and 1 low level detection only method, Bill's WLDS. There are more than three methods for low/high if you dig into it. I just picked the 3 simplest or most obvious conceptually. But simplest not necessarily for a G1 steamer (i.e., radar.) 

I've never understood Bill's approach of not detecting both levels, in addition to being totally against drilling/taping the boiler without a bushing as he suggests. Notwithstanding the safety issues with Bill's probe-to-boiler method, There are problems of HOW exactly do you drill the backhead and clean up afterwards. Ideally(?) I suppose you could drill the boiler and tap the hole while the loco is assembled. Maybe on a Ruby but few if any others. On a Gauge 1 (1:32) you would have to tear down the entire loco. Beyond that there is the mess. And if you did, say, manage to just remove all the backhead plumbing and mount the plug, how do you get the drill and tap shavings out of the boiler? Or, do you just leave them in the boiler? Too long ago since I read Bill's instructions so I do not remember if or how he suggested solving the debri problem. The debri simply cannot be left in the boiler, period. It will foul something up. If for no other reason than you might think it wont. Murphy's law.

As for Bill's use of a timer, that seems problematic on a number of levels (no pun intended.) Ideally all things work as planned and the right amount of water is pumped into the boiler and the pump shuts off. But I can think of a number of scenarios where a problem would arise and things go wrong. I dislike uncertainty, of course live steam and certainty is an oxymoron. 

Why build a water level detection device for only low level? Which is why I have even more wonder at why, when Bill came up with the water fill plug probe he did not include high water level detection. With a boiler mounted probe for low/high level detection takes 2 probes, 2 holes, 2 bushings. With the water fill plug, well ...


When WLDS came up this time, as the subject does periodically, I wondered what's out there... I rubbed my magic Google lamp and... I found a number of miniature liquid level detection devices most for both levels. The one I really wanted to show a foto of I could not find again. It had three dangles(?) 2 the same length and one short. But foto #1 got the principle across, although it is, I think, fundamentally incorrect. Two of the dangles(?) have to be the same length, long, the third short, or it will not work. 

I think Bill's WLDS is the only one that does. All the others depend on some small level of contaminant introduced into the distilled water so the water becomes conductive. Small level as in enough to allow for conductivity but not enough to damage the boiler even in the forever timeframe. 

Afterthought... I forgot not all WLDS things are used to turn a water pump on/off. Some, maybe most, only use it as a safety measure to trigger an red light so one stops soon and adds water. But I did not want to return to the above and edit it all for just safety.


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## Chris Scott (Jan 2, 2008)

Posted By lotsasteam on 13 Aug 2013 01:24 PM 
How about using Acetal ? i do have a thermo injection unit ( 1 inch max diameter pattern) to make Flexite partials! If i can help out in in a pre machining casting let me know! 

Manfred 
Manfred;
Thank you for the offer.


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## Semper Vaporo (Jan 2, 2008)

Posted By Chris Scott on 14 Aug 2013 03:24 AM 
Posted By Pete Thornton on 13 Aug 2013 05:29 PM 
Three methods for low/high water detector. 
Chris, 
I just got one of Bill Ford's WLDS and he doesn't use any ot those methods - so there are Four ! His system, as far as I can see, uses a probe in the water to conduct and inform the WLDS that there is a path. When the probe comes out of the water, even in steam, it doesn't conduct. You can test it using your finger's conductivity, so it doesn't use much power to see the circuit. 

And his probe is mounted in a brass bush with a teflon sleeve to insulate it. Would you like a photo - I don't think Bill is planning to make any more! 
Posted By Greg Elmassian on 13 Aug 2013 09:37 PM 
that's the first of 3 above


I believe Bill's probe uses RF so it does have two elements. They seem to be encased in what I think is a cosmetic sheath for stealth. But I don't understand the mechanics of an RF design so that's a wild guess. The first foto above you can think of nakedly exposed elements or contacts. I don't see any reason they should need or have to be other than exposed. Maybe make them prettier if desired. 

Bill made three variations or models of his filler plug probe. I have two of them - I have not used them - one of those bench queen projects we all have a million of. All Bill's probes detects only low level not high water level. The 3 fotos posted are 3 methods and products for detecting low AND high water level; pump on pump off for our purposes. Bill's WLDS detects low water level only, turns pump on & red led. Pump is shut off via a timer. User sets the timer by trial and error experiments. Not an acceptable method/approach to my mind.

So there are 3 low/high methods (the 3 fotos above) and 1 low level detection only method, Bill's WLDS. There are more than three methods for low/high if you dig into it. I just picked the 3 simplest or most obvious conceptually. But simplest not necessarily for a G1 steamer (i.e., radar.) 

I've never understood Bill's approach of not detecting both levels, in addition to being totally against drilling/taping the boiler without a bushing as he suggests. Notwithstanding the safety issues with Bill's probe-to-boiler method, There are problems of HOW exactly do you drill the backhead and clean up afterwards. Ideally(?) I suppose you could drill the boiler and tap the hole while the loco is assembled. Maybe on a Ruby but few if any others. On a Gauge 1 (1:32) you would have to tear down the entire loco. Beyond that there is the mess. And if you did, say, manage to just remove all the backhead plumbing and mount the plug, how do you get the drill and tap shavings out of the boiler? Or, do you just leave them in the boiler? Too long ago since I read Bill's instructions so I do not remember if or how he suggested solving the debri problem. The debri simply cannot be left in the boiler, period. It will foul something up. If for no other reason than you might think it wont. Murphy's law.

As for Bill's use of a timer, that seems problematic on a number of levels (no pun intended.) Ideally all things work as planned and the right amount of water is pumped into the boiler and the pump shuts off. But I can think of a number of scenarios where a problem would arise and things go wrong. I dislike uncertainty, of course live steam and certainty is an oxymoron. 

Why build a water level detection device for only low level? Which is why I have even more wonder at why, when Bill came up with the water fill plug probe he did not include high water level detection. With a boiler mounted probe for low/high level detection takes 2 probes, 2 holes, 2 bushings. With the water fill plug, well ...


When WLDS came up this time, as the subject does periodically, I wondered what's out there... I rubbed my magic Google lamp and... I found a number of miniature liquid level detection devices most for both levels. The one I really wanted to show a foto of I could not find again. It had three dangles(?) 2 the same length and one short. But foto #1 got the principle across, although it is, I think, fundamentally incorrect. Two of the dangles(?) have to be the same length, long, the third short, or it will not work. 

I think Bill's WLDS is the only one that does. All the others depend on some small level of contaminant introduced into the distilled water so the water becomes conductive. Small level as in enough to allow for conductivity but not enough to damage the boiler even in the forever timeframe. 

Afterthought... I forgot not all WLDS things are used to turn a water pump on/off. Some, maybe most, only use it as a safety measure to trigger an red light so one stops soon and adds water. But I did not want to return to the above and edit it all for just safety. 








Let me jump to Bill''s defense, and, No, I don't know him nor do I have his product on either of my engines.

1st lets follow a scenario of the cycle of water in the boiler from low water to replenishment. The engine is running and consuming steam, so the water level in the boiler is dropping. At some point the WLDS indicates that the water level is in need of replenishment, so it turns on the pump, which runs for some period of time. That period needs to be LESS THAN that necessary to refill the boiler. YES! *LESS THAN! * You do NOT need to immediately run the pump until the boiler is full. Just for giggles, let's say it runs for 1 second and manages to make around 3 strokes of the pump ram and shoves in 3 pumps-full of water. 

Is that enough? 

Who cares? 

If the pump then shuts off, and the water level is back to acceptable, then okiedoakie! Leave the pump off and wait for the next time.

If the pump shuts off and the level is not acceptable, then the circuit will restart the pump (or possibly not even let it get stopped, but just reset the timer to zero and let it time out again) and more water will be pumped in for one more timer cycle.

Is it enough now?

WHO CARES!?! If it takes 10 passes through the cycle of start the pump and run it a few pumps-full, then okay, it took 10 passes. SO WHAT? The boiler eventually gets enough water to cover the low water detector and it quits calling for water to be added.

Now, let's consider a circuit that detects when the boiler level is above the "required" level. What is it going to do? There will be no signal to turn the pump on because the low level detector won't be detecting low level, so what is left to do? Open a blow down valve to blow out the excess? WHAT FOR? Why waste the excess water?

If you are using the low level detector to turn the pump on and the high level detector to turn the pump off, then you might run the pump for, oh, let's guess, 12 seconds once per minute, or if you use a timer to shut it off after 1 second, then it will run for 1 second, every 5 seconds for that same minute. Same amount of water being consumed (as steam) from the boiler being replenished by the automatic systems, but in one scenario you have one huge slug of water being injected into the boiler all at once that will chill the boiler more in one portion of the minute, and the other system injecting 1/12 that amount at a time over the whole 1 minute, thus reducing the load on the fire to reheat the whole slug all at once.


The same holds true for whether you are using an electric pump to move the water or a solenoid to open/close a bypass valve from an always actuating (while the engine is in motion) axle pump. Small amounts of water added to the boiler is better for the integrity of the boiler (less thermal shock) and operation will be smoother (less need to adjust the throttle to maintain speed due to the loss of steam pressure from the large amount of cold water being injected all at once vs small amounts continuously).



One more thing... I note that for the dual level detection system, there are THREE wires. WHY? All you need is TWO. The 3rd connection is the boiler shell itself and the contact points are the boiler water touching each of the wires (the high and low ones) in the plug.



Like Columbo, I have just one more thing...

The "Radar" detection method. Have you ever looked at the surface of boiling water? It is NOT a smooth surface for reflecting any sort of Electromagnetic Wave at any frequency and enable one to detect what the "true" level is. It would have to be some sort of average of the level over time and I fear the uncertainty of that statistical average would be way outside of the parameters of keeping the crown-sheet covered in a boiler and not prime the cylinders due to overfilling the boiler in the process. "Radar" might work for a stationary container of liquid, but not a *boiler* _moving_ on rails.




As for debris in the boiler from drilling and tapping a hole for a detector. It has been pointed out MANY times that doing so is NOT NECESSARY on any of the boilers, as they all have a fill port or other pre-existing bushed hole that can have the plug replaced with the detection device and thus there is no debris to worry about. But for those that do decide to drill a hole and thread it, Bill presented the calculations in an article in "Steam in the Garden" magazine that indicated that, given the hole size and the thickness of the backhead where the hole would be drilled and the recommended thread pitch, there is enough metal to produce a proper and safe seal against the pressure. And any debris that might get left in the boiler is HEAVIER than water or steam and will not FLOAT to the top where it might get picked up into the dry pipe and travel to anyplace where it would cause a problem. Granted, it looks sloppy and unprofessional to leave such debris in the boiler, but there is very little chance of it being a problem.


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## Pete Thornton (Jan 2, 2008)

Why build a water level detection device for only low level? 
I forgot not all WLDS things are used to turn a water pump on/off 

Chris, 
You got it. I do not have an electric water pump or an axle pump, so all my pumping is by hand. The EBT #12 I have has a terribly inaccurate water gauge, so I added the WLDS to see if it helps me become a better hand-pumper. 
Here's the probe on the cab of #12:


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## Chris Scott (Jan 2, 2008)

Posted By Semper Vaporo on 14 Aug 2013 09:03 AM 
Let me jump to Bill''s defense, and, No, I don't know him nor do I have his product on either of my engines. 



You've got excellent observations and conclusions. We differ. That’s life.


































































The three photos are of probes generic to any liquid storage tank for detecting levels. Water is only one application. One I left out was a toilet tank type. But they are used for level detection more analog than digital.


If you Google “low high liquid level detectors”, then select the “images” link above the links list. The types of devices is near infinite. I picked 3 felt to be representative.


Radar in a boiler was supposed to be humor. But to be obstinate (or a ****, opinions differ) I’m sure with radar a high data sampling rate could accurately determine the liquid level. 


Far more than here the topic of WLDS has been covered over the years on the G1MRA yahoo forum and in the G1MRA Newsletter and Journal. In fact G1MRA has fostered quite a number of different designs for probes and electronics with photos and schematics posted and published over the years, which I think is going on more than 12-14 years. 


A key part of the criticism was a boiler without a bush would be rejected out of hand and not allowed to steam at any G1MRA sponsored event. Boiler test/certification is required, I believe, prior to running at any G1MRA GTG or show. Bill’s test results have, in the main, been unconvincing and with long technical debates.


Originally one of the criticisms was the coarseness of the thread versus the boiler thickness. The results, it was said, is just one plus complete thread to hold the probe fast. The suggestion made, a finer thread would have meant more bite, an improvement but still not acceptable.


Odd man out, I don’t think of a boiler as part of circuit unless I’m reminded. Thanks.


Truth be told the means are the same, time. Bill’s uses a timer controlled by a electronic clock. A low/high probe uses time via the difference in length between the low and high probe. With time and patience and driven by critics the times can be made near equal. Important to call attention to what high level means. It means whatever the user wants depending on any variable(s), pump cycle, boiler pressure, etc. 


As far as using an existing bushing on the boiler, maybe. I think the one Bill most often mentioned was/is the the lower water gauge bush since with WLDS the water gauge is no longer needed. Below is an example I posted in 2008, or so, of the problem that can come up. The fitting is well below the top of the flue on an Accucraft 3-cylinder Shay. With others it might work, but there are some caveats. 


I think there is nothing left of this already dead horse. Can we just agree to disagree ?


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## lotsasteam (Jan 3, 2008)

http://dampfforum.info/viewtopic.php?f=26&t=2995 

Here is a complete write up with electronics +pics how to build a sensor/electronic for a servo water pump! i could not find a english translation! 

Manfred


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## Chris Scott (Jan 2, 2008)

Manfred,
Thanks. Now I finally have an incentive to learn German. Wish it had come sooner then I would have understood what my father was yelling at me.


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