Boiler water feed

[heronsgate]

Just thinking through various ideas and wonder if anyone has had any experience of feeding water into a boiler using a 12 volt DC miniature water pump. Boiler pressure is between the 70/80psi range and boiler check valve is the termination of 3/16 diam thin wall copper tube. Question would be what would the water pump pressure need to be for the higher steam pressure. Any thoughts gratefully received. Thanks. (I do know about injectors/axle pumps and hand pumps, just looking at alternatives)

[9F]

I have had the same idea, but I have not found a suitable pump yet to give it a go.
Shall watch the thread with interest.
Rob.

[heronsgate]

Hope I am allowed this, but I have been trying to contact these people for more info.
www.micropumps.co.uk (Usual disclaimer of course)

Forget the price if they work as well as they claim it would be a bonus.

[Deleted]

Hi

Those pumps won't work, they are only 1000 Mbar or 14.7 psi, I don't yet know of an electric pump that has the ability to overcome the usual boiler pressure experienced in our loco's, although I'm always open to suggestions as it's something I've been looking into myself although not spent any real time on R&D yet.

Pete

hmm I stand corrected. I've just reread the products list and note that one type has an output of 7000 Mbar or 101 psi....may be worth a try... keep us posted if you do try it...

[steam4ian]

Australian Model Engineer had an article where the contributor had used a 12V pump to feed water to the boiler.

It worked for him.

If I wasn't so lazy, I'd find the article.

Ian

[pault]

Hi All
The pressure required to push water into the boiler will depend on the dimensions of the clack valve. Generally on most clacks the area of the valve exposed to boiler pressure will be significantly greater than the area the feed device has to act upon. As a result the pressure created by the feed device will need to be significantly greater than the boiler pressure in order to feed. If you can calculate the area of the valve holding it shut and the area of the valve trying to open it, you can calculate the pressure required to start feeding the boiler.
In other words your pump will need to produce a higher pressure than the working pressure of the boiler.
It is common to use a 12v pump to fill the boiler before steaming but I have never heard of one feeding a boiler in steam. Also with most types of pumps the free delivery feed rate will be greatly reduced when feeding against a pressure.
Hope this makes some sense
Regards
Paul

[marshall5]

According to their website the Maxitrak 'Chaloner' boiler is fed by an electric water pump - that might be a good place to start. Ray.

[isc]

Whats wrong with a reciprocating pump similar to an axle driven one, or a hand opperated one, driven by a small motor, geared down to suit? isc

[weldsol]

Got to ask the question what happens when your at the bottom of the sight glass and you find your battery has gone flat.
Go for hand operated pump

[heronsgate]

Thanks for that info Ray, will have a looksee at some point. ISC..Reciprocating pump, yes we have been discussing that aspect as well, not yet finalised any firm plans. (Trying to come up with sonmething neat, waterproof and small) Weldsol..You have to be positive and maintain any battery to such a state as it will serve for the purpose intended for as long as needed, and yes the idea of an electrically driven pump would have to work in conjunction with any other means of water feed.
At least we are getting some good response from this, keep them coming.

[pault]

One other thing to remember, a lot of small pumps will only start when there is no pressure, i.e. the pipe to the boiler must be at atmospheric pressure for the pump to start.

[jma1009]

i have watched this thread with some bemusement...

what is the point of building a miniature steam loco,
then not feeding the boiler as per fullsize?

ive made lots of injectors, and my machinery is pretty basic and archaic,
but they all do the necessary and more, and i assure you that once you understand the principles and have gained the confidence they arent so daunting. i was taught to drive by someone who made commercial injectors as a living for Reeves and Kennions, and wouldnt even consider any other way of feeding a boiler.

cheers,
julian

[doubletop]

A number of the 7.25 guys in our club do this as a third or fourth option after the usual suspects. Try alibaba.com for HP pumps

[heronsgate]

Sorry Julian. What is wrong with changes to already proven ideas. I also have driven a variety of locomotives using injectors on their own for over thirty years now, so no problem there!. Also, where did I make any reference to 'locomotives directly' in my original thread?

Thanks 'doubletop' I will look at your suggestion along with that for Maxitrack.

[digger]

Change for changes sake is not reason enough, using an electrric pump to feed water against the boiler pressure seems alien to me, why bother trying to run a steam locomotive at all? just have done, throw the boiler away and install an electric motor, if you can't steam a locomotive in the traditional method, why bother at all.
I feel the same way about propane fired locomotives (except for the smaller gauges), our friends across the pond seem to favour this method, not for me, there is no real skill involved other than opening the propane valve more.
Rant over.

Digger

[flyingfox]

greetings, although there are those against the use of electric pumps for steam locomotives, it would be a very useful thing to fit to a model steamboat.
regards
foxy

[heronsgate]

I feel that in the light of the majority of responses to the original question I have created enough interest to satisfy my own curiosity. Because of the attitude of members such a 'digger' I feel enough is enough, What ever happened to the world of experimentation. Sorry folk, with those sorts of 'rants' I will go my own way through what is left of life and decide what to do and when to do it without following the pack. Thread, as far as I am concerned is CLOSED.

[redmog]

Feb 25, 2013 17:49:48 GMT flyingfox said:

although there are those against the use of electric pumps for steam locomotives,
foxy

Digger isn't - He fills his boiler with one!

Jan 22, 2013 10:45:44 GMT digger said:

I fill my locomotive boiler via an electric windscreen washer pump,

Digger

[/size]

[steam4ian]

Looks like Mr Heron 's shut the gate.

As for experimentation, why not?

Many kindred organisations have the word "experimental" in their lofty titles. Let's experiment.

Gas firing doesn't do much for me either but often the prototypes were oil fired, again just turn a valve. Oil firing in small sizes has a particular set of problems so maybe it's gas or nothing. Certainly in some of the tracks in forests coal would not be an option.

Has anyone here built a loco with electric operated valve gear?

Has anyone here built a steam turbine powered loco? At least a skilled bloke in my club is giving it a go.

Most here know more than I and are more skilled than I but with some of the attitudes the hobby will die with them.

Regards
Ian

[heronsgate]

Could not resist the message from Ian, yes I have fitted a small electric motor to my reverser. Operates from an almost invisible switch and is set through two micro-switches to stop at either end of full travel. Position between is gained by that awful word EXPERIMENTATION and intuition.
Water feed is completed, I just will have to keep taking the tablets...thanks guys, some make this thread really enjoyable, even for those amongst us that are set to be different from the normal.