Discussion in 'Steam Traction' started by yec2521, Jan 18, 2010.
Have you tried South coast Steam? Not saying that they can provide but it is as good a starting point as anywhere? They seem to do most loco fittings.
Re: Safety Valves
Our group has a set of drawings for Ross 2 1/2" safety valves, as fitted to our 8F. Any good 2 U ? P.M me with your address and i'll see if we can get you a copy posted !
48624 society. (Nutter)
I would also recommend South Coast Steam. Usually very quick supply. See here for contact details.
I am not connected with the company but we have frequently bought from them.
we have been in touch with south coast steam but they wanted us to send them the drawings so not a good lead. thanks simon will be in touch cheers.
if anyone wants to contact me my phone numbers are 07980 156 022 or 01246 206088. time really is of the utmost importance here
As simon said,we have a set of drawings for these,we also have two spare castings which we may be able to sell.The rest of the castings i'm fairly sure came from Swindon Historic Castings.
I see from your phone number you're in the Chesterfield area,it might be worth your while popping over to Rowsley on Saturday when there will be a number of the 8f group around.
hey cheers for the info yeah i'll try and get across on saturday. could you let me have your phone number so i can contact you on sat or at some point to artrange meeting up. cheers. richard
Don't want to spoil the party but, if the Ross valves are for the Stanier 8F I'd think that they are the wrong type of valve, even if they are the same nominal size. Those fitted to Stanier locos were of a much squatter variety than those fitted to 'industrials'. Be pleased to find that I'm wrong, though!
I'm no expert on this sort of thing, but aren't safety valves sized to suit the boiler? An 8F would have a greater working pressure than an industrial and a much greater evaporative capacity, so I'd have thoughts it would require valves of greater cross sectional area.
i'm not entirely sure on this. i'd thought that as long as they were the correct type and set for the required working pressure whether thats 250 psi for a mainline loco or 180 psi for an industrial etc etc then it would not matter. i know that we could make an adaptor flange if the valve seat diameter was different.
If the cross-sectional area of the valve is too large than the valve will open and shut rapidly ("chatter") and soon self-destruct. Conversely, if the area is too small, then bye bye boiler. An 8F valve would be way oversized I'd think.
This is not something you want to mess with in the hope of getting it right. I can't see you getting it passed the boiler inspector unless you have some documentation proving the valves are correctly sized before you light the blue touch paper. If you can't find any drawings or other records of the original valves, then you ought at least to now the rated evaporation capacity of the boiler, or failing that the surface area. Then you could look for similar boilers and go from there.
got another iron in the fire. contacted hunslet and they're checking their archives for the required safety valve drawing and can probably do the machining as well but again if anyone has any drawings they can loan us or a set of valves for sale please get in touch
You could also try tyseley loco works, as i understand they have made Quite a lot of safety valves of different sizes for hunslet steam at the farm.... They may just be able to help?
cheers for that 603 will try it.
Normal industrial Ross pops usually only have 4 hole flanges. A standard LMS pop valve would be way too big and the flange drillings would be totally wrong.
Like 603, I believe Tyseley Loco Works has made most of the safety valves for Hunslet Steam, one of Hunslet's guys has said so at one of their open days.
Most of the Ross pop's that I have are screwed so the flange is irrelevant. that's just an alternative fixing. I've nothing larger than 2", though. I've two schematics for a 2½" valve, one gives a height of 11" and the other gives a height of 6¼" They are like chalk and cheese. The drawings are NOT suitable for manufacture. You really need a lot more information before you specify the valve that you want. Valve size is usually associated with grate area and 2 x 2½" valves are associated with a grate area of 27-30 sq ft for a standard Ross valve. High lift valves are different. However, you really need to know the evaporative capacity of the boiler and go from there. You can't afford to get it wrong.....
Just an idea:
Your group's loco is 2521 of 1952
Quainton has loco 2498 of 1951 (Chislet)
The locos appear to be of identical design. On the assumption that the boilers are identical, could your group borrow the valves from Quainton to have a new set copied, or perhaps Quainton has the drawing you need?
Definately worth asking...
AFAIK, this is out of copyright, but it came from Google books (Locomotive Management - Cleaning, Driving and Maintenance
By T. Hodgson).
It's not a drawing from which you could make anything, but I think there are some observations you can gather from it. The main one is that you're probably going to need castings made, but also the obvious spring. In the world of models, it's common to be a bit experimental with springs, but here you can't afford that.
I hope you figure it out, and that this helps somehow.
If you load up the larger image, you can print off a copy to paper. Certainly if you had no other information, you would be able to design something functional from this. There were many different types of pop valve, so it's not clear if this is the type that is historically correct for your locomotive. Most significantly, I suspect it's not, if your engine is a J94.
If you search for pictures of the MHR J94 conversion you can see that the valves are much taller. They can be seen because the engine has no saddle tank.
cheers people. yeah ghost i have been in touch with the owners of chislet but they are reluctant to lend us the safety valves they have which is understandable as they dont want them lost or damaged which we wouldnt obviously intend to do but we are complete strangers so i can understand their reluctance. and cheers streuth for the picture it should come in handy. cheers people. keep coming forwards if you have anymore information
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