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Added "Applications" and some definitions[edit]

I added an applications section with a brief overview since the article seemed to jump right into types of boilers without really describing what they do. I also created some definitions and added a few boiler accessories. --johntindale (talk) 22:29, 9 May 2008 (UTC)

Counterintuitive Statement re Superheaters[edit]

In the section on superheaters, the article currently says:

It is important to note that while the temperature of the steam in the superheater is raised, the pressure of the steam is not.

This doesn't make sense to me. If the temperature of the steam is raised, shouldn't the pressure in the system increase? Or is the case of an open system where the steam can freely exit the superheater as fast as it wants taken on premise? (I.e., you're increasing the V term in PV=nRT rather than the P term...) If this is the case, I think it should be clarified, because at first glance it just seems rather counterintuitive; if the temperature is increased, either the volume or the pressure is going to increase (and unless the outlet is just to the atmosphere with no flow resistance, increasing the volume is going to increase the pressure at least to some degree). I'm not saying the statement is necessarily wrong, but just that it's confusing, and perhaps someone with better background in the area could explain it more thoroughly. –Kadin2048 05:36, 15 November 2007 (UTC)

I have just modified the paragraphs on the different types of boiler which were hopelessly confused. Went on to the superheated steam section, and quite frankly, not only do I find it "counterintuitive" as you do, but think it is drivel (and I am not in the habit of using such strong terms in WP). I don't know how far a statement such as: "This provides steam at much higher temperature, and can decrease the overall thermal efficiency of the steam plant due to the fact that the higher steam temperature requires a higher flue gas exhaust temperature." reflects accepted textbook wisdom, which is why I hesitate to alter it for fear of being accused of POV because my take on the subject is personal, but if it can be of any help, here it is for what it is worth. — Saturated steam is so called because it still has a large proportion of water in suspension. Water can't expand so it has to go through the engine along with the steam without contributing to work output. This wastes water and fuel burnt to try to boil it; furthermore this also prevents you from using the steam expansively because as it expands the temperature drops and the steam condenses, so even more water will be present in the steam - even more waste. The heat source in any boiler only serves to produce steam. But if you recuperate residual heat after "creaming off" the steam, to dry it; this means that for a given output, less steam will be used, less water will need to be boiled and fuel consumption will fall, or conversely you can obtain greater power output for a given amount of fuel and water. This has been experienced time and time again in the railway world. Turning the suspended water into steam may produce a marginal increase in pressure but one never hears about it so it's probably hardly discernible, however what will be discernable is that use of dry steam in the engine will mean that a much higher percentage of the steam produced by boiling the water can do work, because it is now pretty well all steam (if it were all steam, it would be supercritical). IMO the engine part or turbine of a steam unit is not a heat engine, but works by pressure-differential (the proof is that it can run on cold compressed air). However the steam circuit demands that temperature be maintained above a certain level, at least until it exhausts from the engine when any remaining heat can be recovered if wished to heat the feed water so that less heat will be required to bring it to the boil. The boiler itself on the other hand relies on a heat gradient in the generally accepted sense.--John of Paris 16:31, 15 November 2007 (UTC)
Added an explanation of the original question, with source. "Drivel" (see above) not dealt with: too difficult, sorry. I look forward to some rationalisation of this confusing section from a more knowledgeable editor. ---- Old Moonraker (talk) 16:55, 16 November 2007 (UTC)
So do I. As stated above I am not given to using words like "drivel" and rather regret it today. Your source and quote are welcome and I hope it will stimulate others to come and join us. I don't know what the temperature values refer to, surely not steam temperatures, - not in a locomotive boiler as illustrated anyway. If it's flue temperature as seems to be meant, that completely contradicts the statement I was contesting - transferring some of that heat to the steam must increase efficiency, otherwise the heat would surely just go out of the chimney with a saturated boiler.---- John of Paris (talk) 21:45, 16 November 2007 (UTC)
Afterthought: This picture shows the boiler pressure gauge (right) and the steam chest pressure gauge (left) of a superheated locomotive. The scales are the same, both showing an operating pressure of 280 psi. --Old Moonraker (talk) 06:41, 17 November 2007 (UTC)
Right! and before Chapelon's time there was considerable pressure drop between boiler and steam chest (That certainly decreased thermal efficiency). - and I've still not got over and am appalled by this notion of a superheater decreasing thermal efficiency. Perhaps the editor who put it in could elaborate.--John of Paris (talk) 08:35, 17 November 2007 (UTC)

Regarding the original question by Kadin2048: The equation PV=nRT is only approximately valid for steam below the critical point but can be used to illustrate what happens.
Two processes take place in the superheater tubes:
1. The temperature of the steam is raised. As the system is more-or-less open, the pressure remains constant. So the steam expands and V increases. The extra energy is contained in the higher volume: it can push a wider piston at the same pressure with the same mass of steam.
2. The flow of steam through the narrow and curved superheater tubes causes a pressure drop, due to flow friction.
Just a small but important detail: The engine working on superheated steam is not the same with the one running on the same mass flowrate of saturated steam: in addition to the superheter it has wider steam pipes and cylinders to accomodate the larger volume of steam.
Sv1xv (talk) 18:56, 14 May 2008 (UTC)


Should this article be merged with steam generator? —Mulad (talk) 20:20, Jun 16, 2005 (UTC)

  • No, as a boiler does not have to generate steam. [anon]
  • No: similar, but not precisely the same. Peterkingiron (talk) 18:17, 3 January 2010 (UTC)

combustion air mix[edit]

How is it ensured that enough air gets into a domestic boiler for gas to burn with a blue flame, whilst at the same time heat loss is minimised? --Username132 19:34, 1 February 2006 (UTC)

  • Username 132, what I think you mean in the first part is obtaining the proper amount of combustion air, too much can waste fuel. Yes, that's important. But heat can be lost (wasted) from a variety of problems, such as fireside soot buildup, or waterside scale, both of which will lower the heat transfer, allowing less heat to be absorbed and thus more heat going up the stack.--Sgstarling 20:32, 18 February 2006 (UTC)

The term "Stoichiometry" indicates that precisely enough air is combined with the fuel to complete the combustion reaction. In the real world, achieving stoichiometry is extremely difficult and, in the case of burning natural gas, can result in the production of carbon monoxide (CO). Therefore, most gas-fired appliances add more air than is required for stoichiometry. This is referred to as "excess air". Excess air absorbs energy from the flame and therefore decreases the amount of available energy for the system. Since excess air reduces the efficiency of the gas-fired appliance, the designers of most modern appliances try to minimize the excess air used while assuring safe, clean combustion. —Preceding unsigned comment added by HydronicsExpert (talkcontribs) 03:03, 30 August 2009 (UTC)

supercritical boiler[edit]

I'm not very happy with the supercritical boiler section, it's both a poor definition, and seems to imply the sole reason for supercritical boilers is to help the earth? So this needs to be redone entirely.--Sgstarling 20:32, 18 February 2006 (UTC)

Also, feel free to add anything anywhere to help flesh out this article, I know there are plenty of stationary engineers out there! Let's flesh out OUR area of expertise!--Sgstarling 20:32, 18 February 2006 (UTC)

Edited the spercritical boiler def. for you (all):-) [anon. boiler engineer]

i think we must talking about types of boiler[edit]

i think we must talking about types of boiler for whose dont know

I agree. Such as oil-fired boiler; gas-fired boiler or electric boiler. Also it it good to include the different applications of boilers.1234louise (talk) 20:02, 19 February 2008 (UTC)

Hydronic central heating[edit]

Why does it say woodburning stoves are popular in North America? —Preceding unsigned comment added by (talk) 12:30, 17 June 2009 (UTC)

I'd like to see more real facts, with regard to North America. What is the history -- when was this most popular, where, what were the percentages of installation usage? In terms of current construction, what are the real facts -- where most popular, percentage of new construction? 20:48, 15 November 2006 (UTC)

In the interest of managed redundancy, maybe the history and frequency of use of hydronic boilers in home heating should be channeled to the Wikipedia article on "central heating", or the one on "hydronics" (talk) 15:29, 19 May 2009 (UTC)

Italian Caption Pictures[edit]

I really appreciate the inclusion of pictures, but wish their captions were in English since this is the English version of Wikipedia.--P Todd 21:27, 3 December 2006 (UTC)

Done one two all three. --Old Moonraker 23:10, 3 December 2006 (UTC)

Expert view please[edit]

In the water tube boiler (hot water), water tubes above the feed water drum are depositted thin layer of ashes in light colour. Would like to know this is because of over heating or due to quality of fuel we are using. Currently using furnace oil of 1500 red wood viscosity. --Uthpalaherath 05:01, 14 December 2006 (UTC)

Overview diagram[edit]

What sort of boiler is the diagram next to the overview intended to represent (or symbolise)? It looks like nothing I have ever seen.--John of Paris 13:52, 27 February 2007 (UTC)

Here's one from Babcock's which shares some of the characteristics [1], although the doubling-back firetubes lead from an internal, rather than an external, firebox. At the least, it's a real-life example of the closed chamber from which the tubes return (which I wasn't aware of either). An illustration of a more common type, and possibly not as stylised, would definitely suit the article better.--Old Moonraker 14:36, 27 February 2007 (UTC)

Yes, it's very hard to sum up a 250-year-old technology in one short overview and a stylised diagram. What is shown here is what I believe is known today as a 2-pass boiler. The Babcock one is 3-pass with presumably an oil burner in a single tube, then the gases return backwards, then forwards again through multi-tube bundles. What I feel here is missing is a chronological overview. I came into this article looking for more information on the Cornish boiler. It is barely mentioned except to class it amongst those "of historical interest" but there is no description of what it was or is.--John of Paris 17:04, 27 February 2007 (UTC)

Standby Loss[edit]

I cannot find the actual water volume inside a hydronic boiler (oil). This contributes to standby loss and is surprisingly not incorporated in the AFUE rating. I am seeing more systems with limited water volume, is this a good thing? I hear the government is currently in court defending their AFUE rating system, true? When will the ASME get involved? Thank you!

The "Steam generation power plant " image is incomprehensible and should be deleted[edit]

The "Steam generation power plant" image in the "Supercritical Steam Generators" section ( [[Image:Turmkessel02.png]] ) is a densely detailed construction drawing of some kind and it is completely incomprehensible because it does not label the various sections and equipment items. It should be deleted until someone adds labeling of the various sections and equipment items. Perhaps those sections and equipment items could at least be numbered and then a list be added to the drawing naming each of the numbered items.

If there are no valid objections to the suggested deletion within the next week, I will go ahead and delete the image. Please comment. - mbeychok 04:53, 7 September 2007 (UTC)

Adds nothing to understanding of the topic as it stands. Please delete! --Old Moonraker 06:48, 7 September 2007 (UTC)

Article or discussion of the Hartford Loop?[edit]

I am not a HVAC engineer. I don't really understand the operating principle of the Hartford Loop, but I do know it helps to prevent boiler explosions due to the tank going dry due to a leak, and makeup water hitting the red-hot metal causing a sudden massive steam release that blows the boiler sky-high.

A new article or an addition to this one discussing the Hartford Loop would be a useful addition to Wikipedia. Any HVAC experts want to step up and add it? DMahalko (talk) 15:03, 2 January 2008 (UTC)

Portable boilers[edit]

In response to this edit: One use of redundant locomotive (particularly traction engine) boilers was to provide steam to steam-sterilise soil in high-intensity agricultural operations, particularly greenhouses. An armoured hose was connected to a hollow lance and this was prodded into the ground at narrow intervals. I imagine that health and safety has put paid to this by now. All personal knowledge I'm afraid, but as such no great loss: I don't really think it's worth including.--Old Moonraker (talk) 23:10, 24 February 2008 (UTC)

Thanks for that, it is a usage I wasn't aware of (so I would say it is worth including, somewhere, even if not on the 'boilers' page.)
The thing is, I've looked at that picture numerous times, and that boiler looks purpose-built to me. It's too long to be an ex- traction engine, and the firehole looks far too big to have been a rail loco. Also, there is very little evidence of there having been any fittings present, and certainly none associated with traction/portable engines.
EdJogg (talk) 01:00, 25 February 2008 (UTC)
Reference available, and not extinct after all: there's been a revival with the organic farming movement. [2] I would certainly rather have used a purpose-built example than the uncertified traction-engine conversion I was accustomed to! --Old Moonraker (talk) 07:06, 25 February 2008 (UTC)
Knowing absolutely nothing about this, it seemed appropriate to raise a question at Wikipedia talk:WikiProject Agriculture. 'Steam' is not mentioned on organic farming, so we may have inadvertently found a topic that is not yet covered at WP.
Ummm, 'watch this space...'!
EdJogg (talk) 10:05, 25 February 2008 (UTC)
I guess I'll start Soil steam sterilization. WAS 4.250 (talk) 14:58, 25 February 2008 (UTC)
Well, I think that could be regarded as a 'result'! Thank you.
Next question is, of course, whether the boiler in the picture was used for that purpose, or something different....?
EdJogg (talk) 17:46, 25 February 2008 (UTC)

[Outdent] I'm as puzzled as anyone, but after looking at a few images of similar devices I think that the item here started life as "cornish" type of bricked-in factory boiler. Here's the sort of thing I mean. This has the single fire-tube with separate doors for the fire (above) and ash pan (below—note the notches to adjust the draught). The fittings for the water gauge can just be made out. The only thing that casts doubt is the smoke box: it looks contemporary with the rest, but did stationary boilers have them in this style?--Old Moonraker (talk) 23:14, 25 February 2008 (UTC)

The cylindrical bit sticking out at the back reminds me of the sort of cylindrical corrugated inner firebox that was applied by Hoy to 20 Lancashire and Yorkshire Railway 0-8-0 locomotives around 1903. Can't imagine what this portable boiler could have been used for, but you can see a union pipe on the dome, so whatever its use, it fed some other system for steam heating or driving some separate plant. As long as all this remains a mystery , I can't see the point in keeping the photo in the article.--John of Paris (talk) 08:58, 26 February 2008 (UTC)
The lack of photo evidence available online is not, to me, an indication that such things have not existed. Googling "portable boiler" is too coarse, but adding 'preserved' doesn't help much either. Numerous likely references come up, but the context surrounding the search results usually suggests that what is referred to is more likely a conventional portable engine. Hence I have been hoping for expert help here!
It does not help that the photo title and caption is in Polish (although I revised the English translation a bit).
There is at least one other preserved, and in rather better order. It is located at the Westonzoyland Pumping Station Museum, in Somerset, and is used as a steam source for their engines. It was made by Marshall's and used by Thames Water, and the museum has a webpage devoted to it. Like the Polish example, this one has a very large diameter chimney -- much larger than your average portable -- and there is a carrying cradle for it during transport, but the chimney was so heavy they needed a crane to lift it into position!
Is it possible that these things could have been used at installations in place of fixed boilers, while the latter were receiving maintenance? (I appreciate that many locations would have multiple fixed boilers installed so that such action would be unnecessary, just trying to think of uses for a portable boiler!)
EdJogg (talk) 10:00, 26 February 2008 (UTC)
The image in question is outside an old mine, so perhaps this might provide clues for you regarding possible uses. WAS 4.250 (talk) 13:16, 26 February 2008 (UTC)
Possibly, although donkey engines used in logging and mining (that I have read about) are normally a combination of winding engine/s and adjacent (usually vertical) boiler.
EdJogg (talk) 13:57, 26 February 2008 (UTC)

More images[edit]

I found this Geograph image of a 'soil sterilisation boiler'. This one looks very similar to a conventional portable engine (boiler and firebox), but with no moving parts on top, and the pipework supports the description given. The Geograph steam engine guru, Chris Allen, hints that there are other photos of similar plant on the site, but a simple search did not reveal any. -- EdJogg (talk) 00:32, 24 October 2009 (UTC)


At some stage I'm going to import some appropriately licensed images from flickr of working industrial boilers: Cornish, Lancashire or similar. Example here: this contributor has uploaded a good selection from which to choose. As pics of working, cared-for items, rather than of stripped and unclad relics out of context, do editors think that they should take over in the lead para? The disadvantage would be that the internal features are less obvious.--Old Moonraker (talk) 17:28, 8 July 2008 (UTC)

I'm not a boiler expert. I added an image today because I think it is more in keeping with what you might find in many older buildings in the U.S. I think some good images of industrial boilers would be great but boilers used for domestic heating need to be represented, too. (Not to say that the image I added couldn't be replaced if a better one is found.) The key is to ensure that the images are in context and that a good text-to-image balance is maintained. The rest could be handled by placing a link to their location on Wikimedia Commons. →Wordbuilder (talk) 19:10, 8 July 2008 (UTC)

Article selection for Wikipedia 0.7 DVD[edit]

This article has been selected for inclusion in the Wikipedia DVD release later this year. Therefore we should be aiming to get it a bit more 'up to scratch'.

I am mindful that this article still covers domestic central heating 'boilers', and similar, which are only intended to heat water, not boil it. Surely there is a better article that covers their creation and design? (It should be linked from the lead paragraph, and the subject ignored thereafter.)

There is also the problem that there was an attempt to split the article along similar lines earlier this year, with boiler (steam generator) being created. Since then, only this article has been edited, and I am thinking that maybe the articles should be merged again...? In which case, how should the article be structured?

Thoughts, anyone? EdJogg (talk) 23:38, 16 September 2008 (UTC)

Water heating has sections on domestic boilers: a possible destination for water heating devices removed from here. --Old Moonraker (talk) 05:55, 17 September 2008 (UTC)
Good find (although, to be honest, I hadn't tried very hard!)
That article also has very good coverage about the safety of such 'boilers' and I think it would work well to split the topic coverage between the two articles, 'boiler' only dealing with installations intended to create steam.
We'll need a short section near the start of the article that highlights the distinction and links to water heating, and explains that modern central heating system 'boilers' are still known as such because the earliest systems worked on steam rather than hot water. (Need a cite for that, but discovered this on a plumbing website.) Incidentally, in the same section it would be worth working-in a mention of steam heating on trains as an example of 'current use' (even if only on heritage railways!).
EdJogg (talk) 09:46, 17 September 2008 (UTC)

needs section on ancient use[edit]

Seems like the most prominent early and B.C.E. use would have been in the Roman Baths and the like, and yet they are not even mentioned in this article. I think that should be rectified. PyroGamer (talk) 22:14, 23 February 2009 (UTC)

Duplicated articles?[edit]

There are 2 articles about the same subject boiler and steam boiler —Preceding unsigned comment added by (talk)

steam boiler is simply a redirect to Boiler (steam generator) which was forked in an attempt to separate steam-generating boilers from hot-water heaters (called 'boilers').
Unfortunately, the editor who created this appears to be inactive at WP now.
The boiler and related articles have undergone a number of improvements in recent months, and I think that Boiler (steam generator) should probably be merged back, although I do not have the level of subject knowledge needed to do it.
EdJogg (talk) 12:46, 20 April 2009 (UTC)
Or re-write the pair of them from scratch, as hopelessly confused and unclear in their direction. We should keep the two separate (although I'd prefer "boiler" for steam and "boiler (water heating)"), but neither has much to commend them. I'm very slowly trying to work through a bunch of boiler-related sub-topics, then might think about addressing the overall header articles, but I'm horribly short of time these days. Andy Dingley (talk) 12:55, 20 April 2009 (UTC)
You are right, both articles need extensive rewriting, mainly rearrangement of text. I propose the titles: Hot water boiler and Steam boiler. There are also some strange statements, like The steam generator or boiler is an integral component of a steam engine when considered as a prime mover; however it needs be treated separately, as to some extent a variety of generator types can be combined with a variety of engine units. Sv1xv (talk) 17:43, 20 April 2009 (UTC)
One of the good guidelines for naming is "How would this work as a wikilink, when embedded in a para of text elsewhere?". In that context, disambiguation names like boiler (water heating) or even boiler, hot water work more easily than [[Steam boiler|boiler]] because the pipe trick lets you use the page name and gives a link title of boiler without having to continually re-title it manually. In context, (i.e. in most cases where we'd use this to create a wikilink) the disambiguation is obviously implicit already. Andy Dingley (talk) 19:18, 20 April 2009 (UTC)
No implied criticism from me on your progress through a mammoth task, Andy, (although this is the top-level article and hence most visible!) I would support the boiler/boiler (water heating) pair since the former will be linked by 10s or 100s more pages. A ground-up re-write may be the only solution, but is a far from trivial task -- in the meantime, if User:Sv1xv feels he can re-fashion it in a more logical order, then why not?
As for the quoted text, this (and the article it came from) arose out of the desire to tackle the terminological problem whereby a "steam engine" may be considered to include or not include the associated boiler. I was never convinced that this was the right way to go...and I wouldn't be sorry to see the article disappear as part of any resolution.
EdJogg (talk) 12:53, 21 April 2009 (UTC)
I don't want to go anywhere near "boiler", let alone WP:OWN it. I make it a rule to try and avoid working on broad-scope Wikipedia articles (Suspension bridge!!) as the broader they are the worse they tend to get: too many cooks recycling too many half-read childrens' encyclopedia articles and counting Ghits as indicating objective truth.
As to engine / boiler / locomotive, then I'd regard engines as separate from boilers and locomotives including them, this being one of the more obvious distinctions for the locomotive as being self-contained and self-propelled. Andy Dingley (talk) 13:48, 21 April 2009 (UTC)
I can understand and sympathise your feelings about 'boiler'. Unfortunately, this is a real problem within WP. Minor articles, with limited scope, are easy to sort out, but major articles (train, railway, automobile, and even steam engine, etc, etc) are way off the standard they ought to be if the encyclopedia is going to do a decent job. GWR/LMS/LNER/SR articles haven't even reached GA, yet countless loco articles have achieved FA. Part of the problem is finding suitable reference works -- sufficiently general books tend to be more at a 'child' level, as you mention, with 'adult' books usually concentrating on a tiny aspect of the overall picture.
How do we move boiler forward? EdJogg (talk) 20:13, 23 April 2009 (UTC)

Proposed Merge[edit]

Following-on from discussions immediately above, I have applied merge-to/-from banners to Boiler (steam generator) and Boiler; discussion being directed to this section.

As stated above, I do not feel that I have the subject knowledge necessary to complete this merge, only that 'something needs to be done'!
(Applying the merge tags allows me to tidy my ToDo list!) -- EdJogg (talk) 14:08, 8 May 2009 (UTC)

  • Oppose As was pointed out to me a while back, boiler is "water heaters" and Boiler (steam generator) is "steam for power". That's a reasonable logical split in topic scope, we should hack with the naming and content to match. Probably turning the bare Boiler into a disambig with Boiler (water heating) would be a start. Andy Dingley (talk) 15:17, 8 May 2009 (UTC)
    • Comment -- If 'Boiler' became little more than a DAB page, that would certainly work. The only down side is that so many articles link here (mostly in the 'steam generator' sense). EdJogg (talk) 09:32, 9 May 2009 (UTC)
  • Merge -- At present we have two articles duplicating each other. That is bad in principle. I agree that domestic water heating (etc) needs to be separated out. However I have no stronmg views as to whether it should be a section in a single article or a separate article. I do not think we need boiler to become a mere disambiguation page: I would prefer it to be used for the steam generation article. After all, that should be the primary usage - surely, a "boiler" is a vessel in which water is boiled, not merely a vessel for warming it. Boiler (water heating) would satisfactorily be linked by an "otheruses" capnote. Sorry, I do not have either the time or expertise to do the merge properly. Peterkingiron (talk) 16:43, 10 May 2009 (UTC)
  • Merge -- The present situation is clearly daft. The heating side would seem to be adequately covered already in Central heating which also refers to Water heating. I agree with merging and using a capnote, but suggest that it to point to a suitable existing article. Globbet (talk) 16:37, 3 June 2009 (UTC)
  • Merge and then spin-off Boiler (water heating). Beagel (talk) 20:18, 21 July 2009 (UTC)
  • Merge, agree with Peterkingiron. -- P 1 9 9 • TALK 23:00, 28 December 2009 (UTC)
  • Comment - I have (limited) knowledge in the field. There is a difference between Steam generators and hot water makers. I have worked in many boiler rooms and on many heating systems. I suggest that we merge the articles but, be very specific on the differences. If you folks have any questions just visit my talk page. Tim1337 (talk) 10:48, 19 January 2010 (UTC)
  • Merge The source of confusion seems to be that in British English the word boiler can applied to both a steam generator and a domestic water heater ( ie. a furnace in American English). There should be one article for steam generating boilers and one for domestic water heating boilers. After that the article names, redirects, and disambigs are a less important issue. Petecarney (talk) 11:15, 1 August 2010 (UTC)
  • merge As far as industrial applications are concerned, the same basic design of boiler can heat water, steam or hot oil the main differences being temperature, pressure and heated fluid Jgb2 (talk) 12:33, 21 October 2010 (UTC)
  • Oppose The proposal of merging the articles Boiler and Boiler (steam generator) is similar to the proposal of merging the articles Automobile and Truck. No matter that does not look anything alike - both have the same parts (engine, transmission, wheels, suspension, steering wheel ;) ) and can carry both people (eg. privates) and goods. I agree with Andy Dingley. There are many types of boilers, some of which deserve separate articles. A steam generator for power is a St. Bernard (dog), and a boiler for water heating is a Pekingese (and they have separate articles). --Turbojet (talk) 15:43, 23 October 2010 (UTC)

Proposed re-structure.[edit]

Let's assume that this article is to move to Boiler (water heating) and have scope limited to that, with steam pressure for power in Boiler (steam generator). As it is, the structure is poor and the content included isn't all entirely relevant here.

(If you disagree, or if you want a different name, then I suggest commenting to the thread above on merging. Let's leave this on the hypothetical assumption.)

So, without reading the article what would you suggest as an "idealised" top-level starting structure for an article Boiler (water heating) ? Let's hear some thoughts! Andy Dingley (talk) 09:39, 9 May 2009 (UTC)

Proposed changes:

As I learned with the restructuring of the code in NJ, there are several basic types of boilers now realized in the current code. A boiler is considered as follows:

"Boiler" means a closed vessel in which water is heated, steam is generated, steam is super heated, or any combination thereof, under pressure or vacuum for external use by the direct application of heat. The term boiler shall include fired or waste heat units for heating or vaporizing liquids other than water where these units are separate from processing systems and are complete within themselves.

"Hot water boilers" are classified as units that are low pressure having a volume exceeding 120 gallons or a heat input exceeding 200,000BTU/Hour (58.6 KW) or an operating temperature exceeding 200 degree Fahrenheit, that provides hot water to be used externally to itself.

"Hot Water heating Boiler" means a boiler in which no steam or other vapor is generated, from which hot water is circulated for heating purposes and then returned to the boiler; and which operates at a pressure not exceeding 160m psig or a temperature of 250 degrees Fahrenheit or both at or near the outlet.

"High Pressure Boiler" means a power boiler in which steam or other vapor is generated at a pressure of more than 15 psig. High pressure boiler also means a high temperature, high pressure water boiler or heat recovery steam generator.

--Emjan101 (talk) 23:01, 1 September 2009 (UTC)

Actually, having not considered this for over a month, these would seem like very suitable sub-article titles, and would solve a lot of the issues we have. If these are officially recognised names, then we should latch on to them. We might need an additional article covering low--pressure (steam) boilers, unless there use is entirely historical (Andy?). (What about model steam engines? I don't know off-hand if they fit within this 'high pressure' threshold.)
Boiler will, of course, remain, but as more of an overview and disambiguation page.
EdJogg (talk) 12:54, 2 October 2009 (UTC)
IMHO, as heat engineer, you need articles for following kinds of boilers:
Boiler will, of course, remain, as EdJogg said. --Turbojet (talk) 18:00, 6 February 2010 (UTC)

Dual conversions |°C|°F|[edit]

Boiler#Superheated steam boilers 1,300–1,600 °C (2,372–2,912 °F). Can some one take go at this?? 1,300–1,600 °C (2,372–2,912 °F)?? Peter Horn 21:45, 11 May 2009 (UTC)

Improved link. Peter Horn 21:48, 11 May 2009 (UTC)

Dual conversion[edit]

Boiler#Supercritical steam generators 3,200 psi / 22 MPa 3,200 psi / 220 bar. Can some one morph this into 3,200 psi / 22 MPa; 220 bar similar to 3,200 short tons / 2,900 t; 2,900 long tons? Peter Horn 22:10, 11 May 2009 (UTC)

Or 3,200 short tons (2,903 t; 2,857 long tons)? Why does |abbr=on not work?? Peter Horn 22:16, 11 May 2009 (UTC)

(2)Article or discussion of the Hartford Loop?[edit]

  • Another user made note of the absence of an article on the subject of the Hartford Loop. It is likely that this is a notable enough topic to have its own article (or at least a section in this one). It is just a simple matter of having an expert who can generate a reasonable contribution on the matter (with references). bwmcmaste (talk) 04:24, 25 August 2009 (UTC)

Boiler ticket ?[edit]

Someone has recently added the term 'Boiler ticket' to Glossary of UK railway terminology (under 'B' :o) ) and I am very conscious that my copy-editing of the definition is inadequate. The more I thought about it, the more I realised that the term needs describing properly within WP, and boiler is the most obvious place to put it. Anyone care to have a go?

Stick it into Glossary_of_boiler_terminology?

It may be that the meaning relating to steam boiler safety certificates is a purely British thing, but the term is widely used within heritage railway articles at WP (and websites generally).

While googling for a reference ('required' for the UK rail glossary page!) I discovered the term also appears to be used for a similar certificate, but applying to boiler maintenance skills -- presumably only workers with the required 'ticket'/certificate are permitted to undertake boiler work. This needs to be mentioned too. (Seems to apply to US/Australia ?)

There is a third meaning, usually found in slang dictionaries (and which I don't fully understand - I get the 'boiler' bit, but why 'ticket'?), but thankfully the company web filter would not have allowed me to investigate beyond the search results!!!

the third is presumably a relative of that other well-known engineering term, "Chitty Bang Bang" Andy Dingley (talk) 14:06, 2 October 2009 (UTC)

EdJogg (talk) 13:11, 2 October 2009 (UTC)

A Boiler Ticket may well be a UK thing but it refers to a certified skill of boiler inspection and the ability of a 'ticketed' inspector to issue a safety certificate. Such certificate is necessary for many situations where a steam boiler may cause public injury. So even small model engines may need a certificate if steamed at a public venue.Rjstott (talk) 20:38, 7 January 2012 (UTC)

Why is stainless steel prohibited?[edit]

The article only says that this is so but doesn't give a reason. Does stainless steel corrode when immersed in hot water? Please add. -- (talk) 21:54, 19 August 2010 (UTC)

It's problematic for two reasons: difficult to fabricate and prone to galvanic corrosion when used wet in combination with other steels. Neither of these are insurmountable, particularly with modern welding and NDT techniques, but it does involve more regulation and more checking. In practice, you just don't need stainless steel just to boil water, and it's not cost-effective to try and use it. Where it is used, for cleanliness issues, it's in all-stainless systems. Andy Dingley (talk) 10:01, 20 August 2010 (UTC)
Stainless steel is NOT, under any circumstances, prohibited by ASME Section VIII Division 1 or Division 2, or ASME Section I. This is patently false and should be removed from the article. I am a mechanical engineer designing boilers for a very large chemical manufacturer, and I speak from experience. — Preceding unsigned comment added by (talk) 17:26, 16 March 2012 (UTC)
An interesting outline of why is at (third answer), and I've seen hints elsewhere that the answer is correct, but I can't find a coherent, citeable source. -- Dan Griscom (talk) 02:10, 26 October 2013 (UTC)
To pull the answers out of the above document, stainless steel has lower yield stress, which requires thicker tubing. Add a higher coefficient of expansion and lower thermal conductivity, and you have greater thermal stresses. Add in the chloride ions from salt in most water, and you get stress-corrosion cracking. And that's bad.
Assuming this is all true, all we gotta do is find sources for this. -- Dan Griscom (talk) 11:57, 26 October 2013 (UTC)

For an authoritative answer, refer to ASME Section I, paragraph PG-5.5 (2010 edition): "PG-5.5 The use of austenitic alloy steel is permitted for boiler pressure parts that are steam touched in normal operation. Except as specifically provided in PG-9.1.1, PG-12, and PEB-5.3, the use of such austenitic alloys for boiler pressure parts that are water wetted in normal service is prohibited". The reason for this restriction is explained in a subnote on the same page: "Austenitic alloys are susceptible to intergranular corrosion and stress corrosion cracking when used in boiler applications in water wetted service... ". SV1XV (talk) 14:31, 26 October 2013 (UTC)

Good information; I've tried to bring some of it into the article. -- Dan Griscom (talk) 12:11, 27 October 2013 (UTC)
I've removed the ASME Boiler Code reference from the section on materials, as it was distracting (especially the "virtually prohibited" phrase), and better-addressed in the Safety section. I'll try to drop a reference to the Code into the introductory paragraph. -- Dan Griscom (talk) 12:29, 27 October 2013 (UTC)

Clack valves/top feed[edit]

Unfortunately this article is copied in various guises everywhere and as such must be gramattically and scientifically correct. I have had great difficulty finding anything outside of this wikipedia origin that supports the limescale proposition and perhaps a citation tag is appropriate? Modern systems (2000+) use 'Porta Treatment' and I found no reference to other solutionsRjstott (talk) 20:34, 7 January 2012 (UTC)

The Great Western Railway introduced top feed in 1911. Clack valves delivered feed water onto chutes, which discharged onto two rimmed trays, each 4 foot in length and sloping at 1 in 30. The rims at the lower ends of the trays were notched; the feed water passed in fine streams through the steam space. The trays heated the feed water, and scale was deposited on them. As the feed water passed downwards from the trays through the steam dissolved air from the feed water was released, thus reducing pitting on the tubes. This is a paraphrase from a self-published non-RS source, so no good for a citation I'm afraid. Ning-ning (talk) 22:31, 7 January 2012 (UTC)
It's pretty easy to source (Nock & Ahrons, Hills, Semmens and probably best, Cook's Raising Steam on the LMS, pp.105-107), but it's hard to write it in one sentence.
Top feed only makes a difference because of the feedwater trays in the steam space. Without the trays, it makes no difference - there is no point in merely moving the clack valve to the top of the boiler. The point of this top feed is that the cold feedwater will be pre-heated to the internal equilibrium temperature by taking heat from the steam, not the water.
There are three reasons why top feed is favoured:
  • It avoids disturbing circulation patterns in the water. This is significant in water-tube boilers, where top feed first developed. See three-drum boilers.
  • It avoids the thermal stress of injecting cold water onto hot firetubes - although this was long solved by better clack placement.
  • It reduces limescale. This is because any scale to be formed is preferentially formed on the trays, not the firebox crown (as the hottest part, this is where boilers otherwise like to make it). This scale is relatively unimportant, in terms of its bad effects for overheating (if scale was formed on the inner firebox). Owing to the way it's formed in the steam volume, not by a hot surface, and also due to mechanical movement of the trays, it tends to not build up in the thick, hard layers of sulphate scale, but rather as a granular crud that forms boiler mud, but not scale. Mud is far easier to remove with a weekly washout. Andy Dingley (talk) 23:19, 7 January 2012 (UTC)

Requested move[edit]

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

This page has been moved in accordance with WP:DABCONCEPT. Simply put, the primary meaning of "boiler", whether used for power generation, cooking, sterilization, or heating for the sake of heating, is a thing that boils. This is capable of being addressed in an article, and is effectively covered by the article at boiler (heat). Boilers for cooking, sterilization, or steam generation accomplish these ends by heating a liquid inside. Therefore, any concept article discussing the topic of boilers must discuss their use in heating first and foremost. bd2412 T 22:00, 1 May 2012 (UTC)

– Talk pages indicate some confusion between two different types of boilers, and my attempt to boldly fix that ended in failure. In particular, the steam/power generation type could probably use a better title. Hopefully this can generate some better ideas than mine. D O N D E groovily Talk to me 14:52, 1 May 2012 (UTC) D O N D E groovily Talk to me 14:52, 1 May 2012 (UTC)

I would suggest Boiler (heating) and Boiler (steam generation). Although most steam boilers are for power generation (either by types or numbers), there are some uses such as steam sterilisation that are broader than this. Heat/heating I see as a trivial question, but would generally prefer the gerund. Neither of these are the primary topic, so both require disambiguation (which also frees the simple Boiler for being the disambig page. If anything has chronological precedence, it's the simple open-topped, unpressurised copper tub used for brewing as a mash boiler. Andy Dingley (talk) 14:58, 1 May 2012 (UTC)
  • Comment I originally had Boiler as a disambig page until someone posted to my talk page and pointed out that there are over 1,000 links to the term. Sure we can fix them, but new links will keep on coming constantly. So, I'm of the view that Boiler should be an article with hatnotes and needed. D O N D E groovily Talk to me 20:23, 1 May 2012 (UTC)
The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Renames (again)[edit]

Can we please discuss this, rather than moving the page around every few seconds. I can't even keep track of where the talk: page is, let alone contribute to this. 8-(

My suggestion:

  • Boiler - the disambig. It doesn't matter if there are 1,000 links to the term. If this was a primary topic article at this name, chances are that 500 would be wrong, rather than 1,000 merely not diisambig'ed
  • Boiler (heating)
  • Boiler (steam generation)

Ask the random "Kid on the Clapham Omnibus" what a boiler is and you'll get an answer that I suspect is rather like, "I've no idea, but Thomas the Tank Engine has one". Ask their parents and they'll probably think of the gas boiler for their central heating. There's no clear primary topic between these two. I don't much care about the naming, but the bare Boiler shouldn't imply one of these types over the other.

We should not base any moves on the quality of the articles - the two lead articles are both crap. In particular the lead image of the "heat" article is so unclear as to which type it is that it's labelled as a "steam tractor". Andy Dingley (talk) 10:23, 2 May 2012 (UTC)

Putting aside the Limp Bizkit song, there are two articles listed as being ambiguous to the term at Boiler (disambiguation). One of these refers to a boiler as a device for heating a liquid to the boiling point in an enclosed space, and the other refers to a boiler as a device for heating a liquid to the boiling point in an enclosed space (as a means of generating power). No matter how you slice it, a boiler is a device for heating a liquid to the boiling point in an enclosed space, irrespective of the use to which this heated liquid is put. Therefore, per WP:DABCONCEPT, the terms are not truly ambiguous, but are merely different aspects of the broad concept of a device for heating a liquid to the boiling point in an enclosed space, and this term primarily refers to such devices generally. We could write a new article about the general concept, but it seems to be most generally covered by the current content of this page. bd2412 T 12:19, 2 May 2012 (UTC)
No. Not even wrong Andy Dingley (talk) 12:46, 2 May 2012 (UTC)
Are you prepared to address the WP:DABCONCEPT policy, or do you intend to argue that the Limp Bizkit song is the primary topic for this term? bd2412 T 14:21, 2 May 2012 (UTC)
No, I'm not - because you're spouting nonsense. DABCONCEPT would be a particularly unhelpful route to follow here. No-one here (excluding yourself) is even thinking in those terms. Besides which, if my domestic gas boiler ever started to boil water, I'd switch it off promptly and fix it. These "boilers" are not intended to boil anything. They supply hot water, not steam. Stretching this to some spurious commonality, such that the articles need to be merged, is ignorant nonsense. Andy Dingley (talk) 14:28, 2 May 2012 (UTC)
So basically what you are saying is that the commonality is at a higher level of abstraction than I have proposed. Please note that I have not referred to boiling water, but to "heating a liquid". Even if the commonality were nothing more than "device which heats", that is a concept capable of being discussed in an article. We do not shy away from writing articles because their level of abstractness makes the subject matter difficult to articulate. bd2412 T 15:30, 2 May 2012 (UTC)

Closing this move request was entirely improper. I noted in the move request that I tried to be bold and failed and your answer to that was to be bold. Also, I notified the Wikiprojects at the top of the page of this discussion and you closed before anyone from there even commented. Now they will see the closed discussion and not bother. D O N D E groovily Talk to me 12:23, 2 May 2012 (UTC)

Participants from the related Wikiprojects should focus their efforts on making this article comprehensive to the general concept, as required by WP:DABCONCEPT. This is policy, and for a good reason - it avoids exactly the problem identified above, where this page would become a constant major headache for disambiguators, and a constant target of efforts to implement exactly this solution. bd2412 T 14:21, 2 May 2012 (UTC)


In 1873 marine boilers were generally fed with salt water [3]. Is this still true? Either way we should include this information somewhere, or make it more accessible, as it's a very interesting fact. Andrewa (talk)

It wasn't even true in 1873. I don't know when Evers wrote his book, but I've long suspected that it was aging lecture notes finally bundled for publication. Many things he describes are a few decades obsolete. In 1873 there were plenty of seawater-fed boilers still in use (it depends on the engine design, not the boiler), but "generally" is way off the mark. Freshwater feed had been introduced around a decade earlier and (with the expansion in steamship numbers) this had long predominated. Andy Dingley (talk) 16:31, 26 January 2013 (UTC)
Thank you... That is exactly the information I was after.
So it seems that freshwater feed is the rule today. That was my question initially. And both Wikipedia (in the article namespace, anyway) and the Web answered it very poorly indeed. Perhaps I just looked in the wrong places.
Does Wikipedia already cover this anywhere? If so we need to improve the navigation.
And if not, it's an opportunity to improve the content. Do you have any sources? Andrewa (talk) 17:32, 27 January 2013 (UTC)

Copyright review.[edit]

There was a nice long section on Types of Boilers. Unfortunately, it was copied from this site which is subject to copyright.

Someone might want to use it as a resource to add, in your own words, some discussion about types of boilers.--SPhilbrick(Talk) 20:48, 11 March 2013 (UTC)

three pass boiler[edit]

three pass boilers are the most papular steam boilers in iran that they produced more than 5000 in a year. we use bs 2790 as a their standard and use st35.8 for it's tube. is it equal in all over the word??? i think it is en 12957 that use in en standard. is it true??? — Preceding unsigned comment added by (talk) 15:12, 13 March 2013 (UTC)

Strange almost-reference in Safety section[edit]

The second paragraph of the Safety section ends with what looks like a misformatted reference to a book called The Locomotive. It's not clear what was intended; would someone with a better grasp of the material than me try to clean it up? -- Dan Griscom (talk) 12:33, 27 October 2013 (UTC)

Does "natural draught" include the use of a chimney?[edit]

The "Controlling draught" section didn't explain what "draught" is, nor did the rest of the article. So, I expanded the section into just "Draught", beginning with natural draught. But: does "natural draught" include the use of a chimney? The original first paragraph talked about chimney height being an issue of natural draught, while the subsection on induced mechanical draught also talks about chimney height.

I'd appreciate eyes on the rewritten section to resolve this, and any other issues that may be found. -- Dan Griscom (talk) 00:24, 31 October 2013 (UTC)

Natural draught doesn't include much else apart from a chimney, and a tall one at that. Andy Dingley (talk) 00:35, 31 October 2013 (UTC)
OK, then can you have induced draught with only a chimney? Both Boiler and Draft (boiler) both state pretty clearly that "induced" draft can be due to a chimney. If so, then what's the difference between natural draft (using a chimney) and mechanical induced draft (using a chimney)?
Perhaps the problem is that there is natural induced draught (a chimney) and mechanical induced draught (steam jet or fan)? If so, then both articles need some regrouping. -- Dan Griscom (talk) 03:04, 31 October 2013 (UTC)
Draught is an ongoing compromise between efficiency of heat transfer and efficiency of combustion. Heat transfer is improved by long passages across a wide surface area; gas flow though is reduced by this, so more draught is required to compensate. I can think of at least five sorts of draughting:
  • Little or no draughting. This only works for early haystack or waggon boilers, where the fire is directly beneath the boiler tank and isn't worked hard. These are obsolete post-Watt.
  • Natural draught. A brick or stone chimney. A popular choice for large stationary engines for a very long time. As boilers started to use economisers though, the increasing height of the chimney required became an expensive capital cost.
  • Fan draught. Probably dates from Marc Seguin, who used it on a locomotive with one of the first multi-tube fire-tube boilers. Never terribly popular though, as it is more equipment needing maintenance and a fan fitted in the exhaust path is in a poor gas environment for its survival. It was mostly used for ships, where fans working in clean inlet air pressurised the boiler casing or the entire stokehold. Re-appeared late on steam locomotives when used with condensing locomotives or turbines, as they had too low an exhaust pressure for a blastpipe
  • Blastpipes – a simple mechanism that worked. Whether invented by Trevithick or Hackworth, it appeared early and was recognised almost as soon. Universally applied to small, mobile boilers.
  • Pressurised burners. Late on, for steam cars with small high-density boilers and liquid fuels, the burner became self-sustaining and didn't require any additional draught. Usually the fuel was pressurised, sometimes a compressed air or steam jet drove the burner.
Andy Dingley (talk) 10:30, 31 October 2013 (UTC)
Let me make sure I understand "pressurized burners". These are where a high-pressure pump sprays the fuel into a duct, entraining air for the combustion, and this force alone sucks clean air in and blows burned fumes out. Right? Would this be a form of mechanical draught? (Any citations?) -- Dan Griscom (talk) 11:46, 1 November 2013 (UTC)
Coal needs a draught on it to burn, which is supplied by encouraging airflow of either the supply air or the exhaust. Oil fuels (ranging from paraffin to bunker oil) are burned by some form of pressure-jet burner (trough burners didn't work well or last long). This can either be spraying the fuel from a simple nozzle, like a paint sprayer, or later systems developed more complex ducts to give better mixing. The ducted systems usually have an air fan to encourage flow through the burner. The point is though that these oil burners produce a large flame that doesn't require any additional draught applied for efficient combustion (as coal does).
With the small steam car and launch boilers, this was all the draught needed. The Stanley used a particularly compact fire-tube boiler, White and Doble used water-tube monotube steam generators. Both have very short gas paths from burner to exhaust, so don't need additional draught.
Multi-tube boilers have relatively high gas resistance so maintaining airflow still requires some induction of draught, just to maintain gasflow rather than to draw the fire. However this is much less than required with coal, so a package boiler can usually manage with just the small chimney needed to clear the fumes anyway. It's notable that package boilers can be dangerous if their burner is opened whilst lit as there can be a backdraught of flame out of the firebox – unlike a coal furnace, they don't have enough sustained draught to prevent this. The main reason package boilers exist is that using gas or oil fuels allows a whole lot of simplification and shrinkage to be performed. They just wouldn't be possible with coal.
Andy Dingley (talk) 12:33, 1 November 2013 (UTC)

Rewrite of Draught section[edit]

I'm about to start work on rewriting the Draught section based on the conversation above. I'm putting it in a page under my own Talk, User:dtgriscom/Boiler Draught. Please drop by and see how I'm doing, and offer comments here. Once I think it's reasonable I'll move it into the article. -- Dan Griscom (talk) 01:18, 3 November 2013 (UTC)

I've finished my first pass at the section. Please take a look and let me know of any additions, corrections, deletions, or other suggestions. -- Dan Griscom (talk) 02:01, 3 November 2013 (UTC)
I've installed my rewritten section. There are a number of issues yet to be resolved:
  • We probably need to rewrite Draft (boiler); its definition of draught as the pressure of the air inside the combustion chamber, rather than the flow through it, is probably wrong. It also states that natural draught and induced draft through a chimney are different, which is also probably wrong.
  • I'd like to include some statement that there is a proper amount of draught for a given boiler: enough to fully combust the fuel, while not diluting the heated exhaust gas and reducing the efficiency. But I'd really need a citation to support that.
  • Did I miss any types of mechanical draft?
  • Boy, would it be good to get some citations in here.
  • No mention of pressurized burners, where the draught is provided by the air entrained in the sprayed fuel.
-- Dan Griscom (talk) 00:57, 7 November 2013 (UTC)

Cleator Moor[edit]

Why the side-trip to Cleator Moor? Kortoso (talk) 21:38, 30 July 2014 (UTC)

Yes, I believe iron from Low Moor Ironworks was also popular for boilers. Biscuittin (talk) 17:21, 27 January 2015 (UTC)

Rename (3)[edit]

I have created a new article Boiler (water heating). I hope this will help with separating the steam and hot water functions. Biscuittin (talk) 21:14, 27 January 2015 (UTC)

The article Boiler is almost entirely about steam boilers so I suggest it be merged with Boiler (power generation). Biscuittin (talk) 21:28, 27 January 2015 (UTC)
We can create a subhead in this article for ==Power generation==, and preserve the single title for WP:DABCONCEPT purposes. bd2412 T 21:33, 27 January 2015 (UTC)
I have no objection but perhaps we should wait for some more comments. Biscuittin (talk) 21:40, 27 January 2015 (UTC)

Steam fittings[edit]

Why is there zero mention of steam fittings, or piping, which transports the steam from the boiler to the engine? There must be interesting details about such a topic, yet "Steam pipe" redirects to "District heating", and the disambiguation page only mentions "District heating", and "A pipe used to transport steam from the boiler of a locomotive to the pistons". Pretty sure there is more too it than that! The steam pipe on a locomotive is A steam pipe, not THE steam pipe. I feel this is a neglected topic, in light of the massive and complex steam-transport systems used in many facilities and in steam ships, which used steam for a variety of tasks. Steam fittings and pipes had to withstand massive pressure and thermal stresses in some cases, and often had to include flexible joints (such as articulated steam locomotives). And, on top of that, steam pipes are also used for heating systems with independent boilers; you don't need to be connected to a district steam heat plant to use steam pipes to heat your house or building!.45Colt 19:57, 8 September 2015 (UTC)

Furnace in North America?[edit]

A boiler is not called a furnace in North America. A furnace in North America usually generates heat via natural gas, although there are some furnaces that still use oil to do that. No water involved in it at all. In North America you can also find electric baseboard heat & radiators in older homes, the latter of which might be more akin to a boiler as they generate steam heat. A better term for a boiler would be the standard North American hot water tanks, or perhaps the newer tankless on-demand hot water heaters. Neither of which actually boil the water, though some older hot water tanks have adjustable settings that could set the temperature fairly high. Newer ones don't go above 110F so that people don't get scalded in the shower or bath.

At any rate, I think the sentence that equates a boiler to a North American furnace doesn't cut it. ScarletRibbons (talk) 10:52, 14 December 2015 (UTC)

In the US, not all furnaces are boilers (warm air systems rather than hot water are common), but boilers are still called furnaces. Andy Dingley (talk) 11:07, 14 December 2015 (UTC)