Talk:Reed water tube boiler

Andy Dingley, about [https://en.wikipedia.org/w/index.php?title=Reed_water_tube_boiler&diff=818326138&oldid=818325110 this edit] – I wouldn't dispute the idea that the steam dome was principally where the steam was collected, but I'm confused by the idea that it was only rarely where the steam leaves the boiler. From Steam dome, this, as I understand it, is evidently the case. And, per [https://web.archive.org/web/20170214153537/http://www.gracesguide.co.uk/images/3/32/Er18960214.pdf this source] (p. 172), it seems to me strongly implied: "In the upper chamber and dome a simple but effective form of separator is fitted, which ensured freedom from priming even at the highest rates of evaporation." To me, that says that it was from the dome that steam was fed to the engines. I'm hampered in this by a severe lack of detailed sources, but would you object to a change of wording to incorporate both your meaning and mine? For example, "Steam was collected inside a dome on top of the top chamber, from which it was fed to the engines ..."? Cheers. Nortonius (talk) 23:54, 2 January 2018 (UTC)

• The point is, why is there a dome there at all, and what is its primary purpose?

: The dome is there to provide a high point, above undisturbed water, in order to collect dry steam with minimal risk of carryover and priming. Steam is taken from there, but it's far from a given that this is where the pipework to the stop valve leaves the boiler's main shell. It was at one time, but as boilers became larger relative to the space they fitted into, it was more usual to take an internal pipe from inside the dome and lead it out through a more accessible piece of the steam drum.

: For steam locomotives, it's usual to place the regulator itself inside the dome, but of course that's not relevant to ships.

: I've no strong feelings about wording, but I think that the collection aspect should still appear first. Also is it worth mentioning that it goes to the stop valve, rather than directly to the engine? Andy Dingley (talk) 01:33, 3 January 2018 (UTC)

::Ok – you are aware that there's no superheating of steam in this boiler? To that extent, I'm only interested in the fact that it appears that in this boiler, steam passed out of the confines of the boiler via the dome. I'd taken the interposition of a stop valve or regulator as a given, and probably felt that it was more relevant to the operation of the engines; so I'll happily add a word or two about that. Cheers. Nortonius (talk) 03:55, 3 January 2018 (UTC)

::: Who mentioned superheating? Andy Dingley (talk) 11:21, 3 January 2018 (UTC)

::::I'm sorry? I was just wondering where else steam might "leave" a boiler other than via the dome – I guessed that superheated steam might take a different route. But it's really no matter! Happy New Year. Nortonius (talk) 11:54, 3 January 2018 (UTC)

::::: It leaves via the dome, but that doesn't imply that the dome has a steam pipe sticking out of the side of it. This was done for some destroyer-size boilers, but not AFAIK for the Reed. It was also very rare for steam locos - the few that do show it are quite distinctive, as they have a massive Y-shaped pipe that other locos don't.

::::: Superheater supplies on firetube boilers were routed internally from the dome or collector to an internal header in the smokebox or combustion chamber, then through the superheater elements. On watertube boilers for ships though, they usually emerged from the boiler drum and casing, then back in to a rather separate set of elements, somewhere in the flue or nestled in the tube bank. You can clearly see them from the outside as two distinct sections. Andy Dingley (talk) 12:32, 3 January 2018 (UTC)

::::::Understood, and yes, there's the problem: I haven't seen a single description or diagram of a Reed water tube boiler that shows the relevant arrangement, nor how feedwater entered the boiler, for that matter. The Science Museum in London has an excellent cutaway model that used to be reasonably well illustrated on the web, but they've updated their online format so the photos are gone, and the only snapshot at archive.org doesn't show them either. Although I'm sure it once did. And the only relevant detail that I would swear to is that there was no superheating. Anyway, I have no source. Hence my reluctance to say anything about steam leaving the boiler other than via the dome, which is where it was collected. If you know of a source, on the other hand ... Cheers. Nortonius (talk) 12:46, 3 January 2018 (UTC)