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Post by andrew7931 on Aug 27, 2015 20:49:55 GMT
Hi
I have been trying to hydraulic my Doris and there is water getting to the cylinders so to me that' the regulator is leaking so I have shut it and it's still leaking so I took off the regulator dome and it's like a sliding brass block that moves from side to side but only moves about 1/4" so why is it still leaking I don't know much about the black 5 thought that lbsc just used a disk metherd of regulator. Thanks
Andrew
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Post by Deleted on Aug 27, 2015 21:06:18 GMT
Hi Andrew
That is a common regulator design for LBSC, the valve shouldn't be brass though, it should be copper or I guess Bronze would do the job too. You may be able to stop it leaking by removing the valve and lapping it until dead flat...you may need to do likewise to the regulator body too.If it is the valve leaking due to poor surface you should be able to test this by putting a smear of oil between the valve and body, if it seals better with oil then you'll know that you just need to lap the two surfaces to get it to seal properly...Take the valve out and rub it over some fine wet&dry that's fixed to a piece of glass, use some oil as lubricant, this should lap the valve in nicely, your aim is to get it dead flat with no scores at all. The regulator body itself may not be so easy to do but basically it needs the same treatment...
Pete
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jma1009
Elder Statesman
Posts: 5,900
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Post by jma1009 on Aug 27, 2015 21:23:05 GMT
hi andrew,
ive never been able to get a regulator valve to seat ok for a hydraulic test so i blank off the steam pipes from the superheaters (which also tests the superheaters).
there are all sorts of wheezes and dodges to get a better fit. some are very difficult to achieve once the regulator is installed in the boiler. brass is quite ok for a regulator valve. but the face of both valve and body can be checked with engineers blue moving the valve only the direction it moves in service, and can be lapped in with brasso but dont let the brasso dry out. it is a laborious awkward job on a regulator already fitted. then before the hydraulic test add a dollop of thick steam oil onto the seat of the valve and work the valve back and forwards a few times with a downwards pressure before putting the inner dome back on.
make up some blanking plugs for the steam pipes. you will probably have to remove the smokebox for this.
of more concern is the fit of the piston valves - the above problems pail into insignificance compared to the piston valves.
Brian (runner42) has a very nice Doris he is completing.
cheers,
julian
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Post by runner42 on Aug 28, 2015 0:24:45 GMT
Hi Andrew,
I fully endorse Julian's advice if you have a regulator that is leaking due to poor contact between the body and valve. But before you go to that extent it's appropriate to point out that the regulator is designed to operate on a steam pressure differential to keep the valve in contact with the body, if somehow you are in the hydraulic test not providing that pressure differential then the valve is going to leak. Also the ideal position for the boiler is to be upright just in case the valve becomes displaced. Make sure that the regulator is shut when the lever is set to the closed position. There maybe end stops fitted to the regulator and these may be causing the valve to not fully cover the opening in the valve body. There is a V cut in the leading edge of the opening on the valve body which is a slow start if this is exposed in any way it's going to leak. Unfortunately this cannot be checked by looking at the valve in position because the operating mechanism is obscuring the valve opening, it has to be removed from the boiler.
Why are you undertaking an hydraulic test? Did the regulator operate correctly on steam prior to this, if so seal off the boiler as Julian has suggested?
I have other comments that may be pertinent but it's best that you take one step at a time and post your findings.
Brian |
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Post by andrew7931 on Aug 28, 2015 7:57:54 GMT
Hi guys thanks for your input I have never steamed it as I have just got it . On closer inspection I can say that it has not seen a fire as the front tube plate and smoke box are like new also when the water was leaking out of the cylinders the water was not covering the sliding valve in the regulator dome when I shut the regulator one way or the other it makes no diffrence so am I right in thinking that it is leaking somewhere else on the regulator  On looking in the steam dome I can see the regulator rod coming from the backhead to a rectangle shaped brass block that is screwed in place and then there the sliding valve on top of that which the regulator rod moves it open and shut could it be leaking under the brass block ? Thanks Andrew |
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Post by Shawki Shlemon on Aug 28, 2015 8:07:30 GMT
I always do what Julian says , and this has an advantage of checking the S heater for leaks too at the same time by keeping the regulator fully open . Slightly leaking regulators is good to cool the S. heater while steaming and at idle , ensure drain cocks are open .
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Post by runner42 on Aug 28, 2015 8:30:18 GMT
An aside you should fill the boiler completely when undertaking an hydraulic test, it appears that you filled it only to show water in the water gauge???
If that is so and water is leaking into the cylinders it must be leaking into the regulator body due to hole somewhere or into the threaded pipe that feeds the steam output to the superheater areas marked in red.
Brian
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Post by andrew7931 on Aug 28, 2015 9:32:35 GMT
Thanks runner42
Yes that is my thinking I was filling it till the water started to come out of the cylinders so I could determine were abouts on the regulator it could be coming from will I be able to take the regulator assembly out to fix it ? Also the valve on top when I move the regulator the valve dos move but I see no hole/v shaped grove for the steam to go in on top when looking down on it is this right ?
Thanks Andrew
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Aug 28, 2015 10:54:02 GMT
Hi Andrew,
Have you asked your boiler inspector about this? If there are no certificates he may require the boiler to be removed from the frames, and whilst a pain in one sense, you would be able to carry out some types of work more easily.
Pete.
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Post by andrew7931 on Aug 28, 2015 19:13:40 GMT
Hi I think that taking the boiler out would be a good way forward can I take the regulator out of the boiler to see if I can find the leak ??
Thanks
Andrew
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Post by runner42 on Aug 29, 2015 5:45:13 GMT
Thanks runner42 Yes that is my thinking I was filling it till the water started to come out of the cylinders so I could determine were abouts on the regulator it could be coming from will I be able to take the regulator assembly out to fix it ? Also the valve on top when I move the regulator the valve dos move but I see no hole/v shaped grove for the steam to go in on top when looking down on it is this right ? Thanks Andrew The V shaped cut-out is on the regulator body so this is not seen because the cross member of the actuating mechanism is obscuring the cut out in the valve, which if removed the V shaped cut-out can be seen through the cut out in the valve. To remove the regulator you have to remove the boiler from the locomotive else remove the smokebox.
Brian
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Post by andrew7931 on Aug 29, 2015 8:33:47 GMT
Hi Brian
What is the best way of getting the regulator out one I have took the boiler out off the frames I just hope I can repair it any help will be very welcome
Thanks
Andrew
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jma1009
Elder Statesman
Posts: 5,900
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Post by jma1009 on Aug 29, 2015 9:30:37 GMT
hi andrew,
brian has supplied the drawing above and it needs careful study if you are not familiar with the LBSC method of regulator steam pipe assembly and parts being screwed into the plates without silver soldered bushes.
look carefully at what kind of sealant has been used. if it looks like loctite adhesive rather than some form of liquid gasket sealant then you are going to have fun and games.
remove smokebox, and very carefully undo the screws holding the wet header to the part that screws into the smokebox tubeplate. you dont want a screw shearing off.
be very careful when removing the part that screws into the smokebox tubeplate that the regulator steam pipe screws into at the same time. you dont want any stripped threads in the copper or the regulator steam pipe. you will probably have to use molegrips on this part to unscrew it.
the regulator steam pipe may unscrew from the regulator body during the above. put a long length of rod in this tube - you dont want it falling down inside the boiler where it will be impossible to recover. if is doesnt unscrew from the regulator body as part of the above it can be removed separately using a rat tailed file. dont let the regulator body fall into the boiler.
a common fault with the LBSC arrangement is bad threads on the regulator steam pipe if made of copper or of too thin a wall thickness, or the pipe being the wrong length or the threaded sections being the wrong length.
i would not remove any of the above unless you are absolutely sure the regulator assembly is leaking other than via the valve and portface, and you have all the taps and dies and material to make replacement parts if required. thickwall copper tube for the regulator steam pipe is particularly difficult to get these days.
cheers,
julian
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Post by andrew7931 on Aug 29, 2015 12:42:17 GMT
Hi jma
Well as you say it's sounds a tricky job to undertake but I cannot think what else it could be as the water was not up to the sliding valve in the dome when it started to leak. do you have any other ideas of what it may be ?
Thanks
Andrew
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jma1009
Elder Statesman
Posts: 5,900
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Post by jma1009 on Aug 29, 2015 15:52:26 GMT
hi andrew,
it sounds very much like it is those internal joints that are the problem.
before you remove the regulator assembly, can i suggest you blank off the wet header orsteam pipes and do a proper dummy run boiler test before submitting first to your club boiler inspector. that way you will then know if there are other problems with the boiler.
cheers,
julian
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Post by andrew7931 on Aug 29, 2015 22:02:01 GMT
Hi Julian I think so too I will get the smoke box off and blank off the wet header like you said and see were that takes me
Thanks
Andrew
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Post by runner42 on Aug 29, 2015 22:57:07 GMT
It appears that your in very good hands with Julian's advice, particularly undertaking a hydraulic test before proceeding further. One thing of particular importance is that the copper tube if thin walled doesn't have sufficient metal to take a thread and will produce problems when assembling it and can split if the alignment of the regulator body or smokebox bush is slightly off and stress is placed on the thread. I overcame this very problem by producing two terminations made of bronze or gunmetal having a good wall thickness silver soldered to the tube.
The removal of the regulator may be straightforward because it appears to be un-steamed but that's a dialogue for the future.
Brian |
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greensands
Part of the e-furniture
Building a Don Young 5" Black Five
Posts: 409
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Post by greensands on Aug 30, 2015 9:05:01 GMT
Julian - which particular type/grade of liquid gasket sealant would you recommend for this type of application? - Reg
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jma1009
Elder Statesman
Posts: 5,900
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Post by jma1009 on Aug 30, 2015 12:38:40 GMT
hi Reg,
i used Red Hermatite for years and years but it is no longer available and the 'new' replacement isnt anywhere near so good.
so for the last 2 locos ive used expensive Pro Seal 'copper XS hi temp HTV silicone instant gasket' obtainable from most car part shops. you mustnt tighten it up until it has 'set'.
ive tried Hylomar 'Univeral Blue' gasket and jointing compound but didnt get on with it as it is non-setting.
cheers,
julian
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Post by andrew7931 on Sept 1, 2015 11:33:48 GMT
Thanks to you all for your valuable information I will up date when I have got any further on with the boiler test
Thanks
Andrew
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On looking in the steam dome I can see the regulator rod coming from the backhead to a rectangle shaped brass block that is screwed in place and then there the sliding valve on top of that which the regulator rod moves it open and shut could it be leaking under the brass block ? 
