Dave H
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Posts: 91
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Post by Dave H on Mar 22, 2013 14:00:11 GMT
Good day gentlemen, this is my first post here as new to this forum and new to the hobby. I have recently purchased a semi complete 3.5 inch LBSC Princess Marina. It has had two Hydraulic tests in the past, (the second one is still valid but apparently due to the new regs useless) but has never been steamed. At my local Club who will carry out this new test, (to check all of the fittings as well as the boiler, 120 PSI for 80PSI working) I have been advised to seal off between the dry header and the cylinder feed pipes to discount a slightly leaky regulator, (it leaks on compressed air and I am hoping that once in steam, the expansion due to heat will help seal it, time will tell, but for now I need to discount it for the test). My question is, (picture of the joint in question attached) will I need a small copper disc inserted in the joint, or will a rubber disc, ie a tap washer, hold the pressure, (120 PSI) it was suggested to put a ball bearing or Viton ball in there, but there is not enough give in the pipework to allow that. I also don't want to risk the thread on the header with too much stress for obvious reasons! Any advice would be welcome regarding this, the first of many problems that I envisage in getting this locomotive up and running. Regards Dave  Attachments:
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Post by Deleted on Mar 22, 2013 14:38:34 GMT
It has had two Hydraulic tests in the past, (the second one is still valid but apparently due to the new regs useless) I can't see why you can't have a steam test under the new regs, whilst still using your existing hydraulic certificate for its remaining period of validity. |
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Dave H
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Posts: 91
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Post by Dave H on Mar 22, 2013 14:45:20 GMT
That would be the ideal, but if I want to run at the Club I have to abide by their rules, understandable.
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Post by fostergp6nhp on Mar 22, 2013 16:23:23 GMT
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Post by ejparrott on Mar 22, 2013 16:32:29 GMT
Current valid hydraulic certs remain valid until they expire. Your club has no right to demand another hydraulic.
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Dave H
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Posts: 91
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Post by Dave H on Mar 22, 2013 18:59:31 GMT
While I appreciate your comments and indignation on my behalf chaps, at the end of the day if I want to belong to this particular club and run on their track I have to toe the line on their requests. I did think it a little harsh that a new test was needed as my current hydraulic runs until Jan 2016, but with this new and as far as I can ascertain, not particularly well thought out series of changes, everyone seems confused by them and are, "covering their arse's" so to speak, understandable I guess. Boiler examiners/testers are to all intents and purposes only hobbyists after all, who needs to get embroiled in litigation in this day and age because of a misenterperatation in the regulations, not me that's for sure! I have no doubts that this goes for the rest of the kingdom as well. Anyway, needs as needs must, I don't want to ruffle any feathers there or on here, (this is my first post after all!) So, back to the question and back on topic, would a rubber, or that type of soft material, seal the joint in question to 120 PSI?. Dave, the fence sitting sort of guy.  |
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Post by fostergp6nhp on Mar 22, 2013 19:25:35 GMT
What about a piece of rubber under the regulator puck? Is the smokebox joint a flat face or the more usual conical face?
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Dave H
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Posts: 91
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Post by Dave H on Mar 22, 2013 19:37:58 GMT
The new rules say that the Superheaters need testing on the hydraulic test, that means sealing off after them, (my joint in the smokebox prior to the split to the cylinders) if I read your suggestion correctly, then this would seal things off before the superheaters, correct? I am a novice here after all, but hey, many thanks for the consideration, I am here to learn. ;D
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Post by Deleted on Mar 22, 2013 20:07:25 GMT
Hello chaps----------- I've not been privy to these proposals yet so am responding ONLY to what's being posted on here...... Can't the superheaters be tested separately ?? Do they HAVE to be assembled on the boiler ??- After all it's the mechanical integrity that's undergoing test so pre-assembled must surely be better if only from the visual-inspecting point of view ?? Just a thought ---------------  |
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uuu
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Post by uuu on Mar 22, 2013 20:27:36 GMT
Yes, I would think that a bit of rubber would do the trick just fine.
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Dave H
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Post by Dave H on Mar 22, 2013 20:29:51 GMT
As far as I can understand it is about mechanical integrity of the conglomerate of parts as a whole, sensible? obviously, a pain in the Jack Jones? indisputable!.
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Dave H
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Post by Dave H on Mar 22, 2013 20:31:27 GMT
Many thanks UUU. |
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uuu
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Post by uuu on Mar 22, 2013 20:43:37 GMT
I would think that a new test is a very sensible thing to do. You haven't witnessed the previous tests. While you take comfort from the existing certificates, they are just bits of paper. When you've seen the boiler at pressure yourself, and have had a competent person that you trust give it an examination, then this will validate your purchase, and you'll feel much more confident when you steam the boiler for the first time.
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Post by Deleted on Mar 22, 2013 21:00:09 GMT
As far as I can understand it is about mechanical integrity of the conglomerate of parts as a whole, sensible? obviously, a pain in the Jack Jones? indisputable!. ---------------------------------------------------------- Yes, I suppose so --- especially in the smaller gauges... It is an extension of the main pressure vessel after all....May I just go off-topic a tad ?? Have a look at the photo you posted...The petticoat pipe seems to be slightly out of line to me...Good luck with the finish-build..... |
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Dave H
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Post by Dave H on Mar 22, 2013 22:00:02 GMT
Ha! I knew someone would notice that, I only saw it myself on taking the photo earlier today, suffice to say that it is on the, "to rectify" list.
Quite correct in your thinking UUU, it will make for a more confident first steam and as you say, the certificates I have are only bits of paper that I have no knowledge about, (and seeing as I am encountering more and more little, "incorrectnesses" ie, the petticoat pipe, it is best to be sure of the pressure side of things at least.
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jma1009
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Post by jma1009 on Mar 23, 2013 0:40:02 GMT
hi dave,
an annealed copper disc plus an ordinary 0 ring, or a copper disc plus a circular piece of rubber will do fine.
i would do the test at home first using the tender hand pump. make sure all the air is out of the boiler and only pump it up to the limit of your pressure gauge unless you have a bigger gauge.
you need to make plugs up to blank off the safety valve bushes after removing the safety valves. keep the plugs handy for the official test.
nothing worse than having an unprepared boiler to test if your a club boiler inspector...they havent got all day to faff about blanking bits off for you and curing minor leaks on fittings etc.. the boiler inspector will i'm sure appreciate it if you prepare the boiler for the test first!
what club is it??
cheers,
julian
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Dave H
Involved Member
Posts: 91
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Post by Dave H on Mar 23, 2013 9:34:50 GMT
Yep, that is the intention Julian, I have blanking plugs, (and one with a quarter by 40 tpi me adapter to fit the clubs test rig) so as suggested by one of the potential testers I will take it up to 100 PSI on the tender pump first and attend to any weeps I find. I also intend to give it a 20/30 PSI compressed air test with the soapy water paint brush first, (as suggested by one of the clubs testers, an idea I had already had) so when it finally does get the official test it should breeze through.
On the subject of the petticoat pipe problem, I had a run around the Locomotive with a torch last night and found lots of gaps around the smokebox area, so a lot of remedial work needed there. Considering the problems and unsatisfactory aspects of some of the construction I have found so far, (ash-pan/grate too small, numerous unions still loose etc) it looks like my purchase is not as far down the road to completion as I first hoped, an even better reason to ignore any past certification. I did manage to contact the original builders (two, the second was very unkind about the first!) but neither were very helpful or forthcoming about aspects of the Loco, both grumpy old men to be honest!
I think that the best way forwards for me is to treat it as a complete renovation/build and work through Curly's book from the start, that way it is, "my" Locomotive and I will know all of its nuances, (I would and do the same with Motorcycles) Ce-st La Vie as our friends across the Channel would say.
As to the Club? all I will say is they are a bunch of very friendly, knowledgeable and welcoming Gentlemen, it is a pleasure to have made their acquaintance. ;D
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Post by ejparrott on Mar 23, 2013 9:37:10 GMT
On commercial boilers, the test code does state, article 8.2 "Certs supplied by comm. boiler makers can only be regarded as shell test..lah de dah..must undergo further 1.5x hydraulic test". Fine. You says its had two tests (and we don't know if its a commercial boiler anyway?), we assume the latter at least is a blue book model eng test. I can't now find the note about accepting old certs.
Article 10.7 states that superheaters are to be fitted "..recommendded...given an intial 2xWP test...". 10.8 state "..repeat tests....boiler shall (shall=mandatory) be fitted working components..." but does no include the superheater. 10.9 states "If practical, the superheater should be included in the repeat pressure test... For superheaters the Boiler Inspector shall (Mandatory) assess the testing requirements on an individual bassis.....". To me, as an inspector, it is not practical to test the superheater once fitted, so its noted on the WSE that it can't be tested. I will however be looking for new superheaters to be tested on new engines, or refits where old ones have died.
Anyway, my Lilla used to leak at the regulator regualy, the solution was a disk of 2mm rubber clamped between the working face and the disk. We've since modified the disk and it now seals anyway.
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Dave H
Involved Member
Posts: 91
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Post by Dave H on Mar 23, 2013 10:04:13 GMT
It is a non commercial copper boiler with a blue book certificate, (Southern Fed). It has it's ID stamped on the backhead by the original testing club.
The first test was at 2 x WP prior to fitting to the frames, the second at 1.5 x WP cladding off, I hope I don't have to remove the Superheater, but as I have said, with the little things I have found, including the leaky Regulator, anything is possible!
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Post by Deleted on Mar 24, 2013 21:52:29 GMT
Hello Chaps---------- DAVE H, I agree entirely with both your chosen line of approach for this model (ie treat it as a renovation from now on) and your "observations" within the larger Model Engineering fraternity }--- a} yes, you will encounter some grumpy old men--but not that many, and b}--Discretion is the better part of valour..PS I run a pair of Enfield 500cc Bullets as well so appreciate your comments there...
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