hand pump for vertical boiler

The time has come to make a pump for my coal fired vertical boiler. Grate area is 11.5 sq.in. Anyone got any advice how big a pump I need? Some sums suggest that to keep up with a good fire I need 14mm bore and stroke, but that seems on the big side.. What have others used?

Edited By duncan webster on 30/06/2023 15:45:12

Edited By duncan webster on 30/06/2023 15:48:34

I would have thought that 1/2" bore and stroke would be ample. I have a 6"verticle with a grate area near twice that size and the pump is 15bore x 22 stroke. Noel,

well that's handy because I've got some 1/2" bore *5/8 OD brass tube in stock, thanks

Duncan, You didn't say if you had injectors and/or shaft driven pump(s). If you are just using a hand pump to keep up with up with steam usage, don't make it too small as you don't want to be pumping all the time.

If you are using it for initial filling of the boiler, too small a pump will take ages to fill the boiler.

Bob

I've got an injector, don't know if it works, but if it doesn't I'll either make it work or get another one. My patent way of filling the boiler is to connect the mains water to the injector overflow, or the pump suction. Then open main stop valve to let the air out. Much easier than pumping away furiously.

Hand pump is just for that panic moment when the water is low and the injector packs up.

Edited By duncan webster on 01/07/2023 19:50:21

Duncan,

Have you thought about one of these? I have had one for boiler testing for some years now and it is remarkably good. Use the pump unit (quite nicely made) and chuck the rest. I doubt you could buy castings or bar stock for the price.

https://www.ebay.co.uk/itm/334740602835?hash=item4df0183fd3:g:Q9wAAOSwKCheJJlt&amdata=enc%3AAQAIAAAA0EVjKjwnfJtTDFYek0kr4I3ufrI7chZHwaKasFDpac1CIvOODZmcogM9gjqBUhjrhlrekRE4UuaCxDU0Tp1CXRzX7YHgtZs7xrtH4xTXy%2FOWqOyBzvl1Mlz3nlaIgGW%2F8IHBqVRnTe3BgEkKNBM7ELu5x8oMXpEaXR9tcObuJVZ21qzzI1e6qXtgORLE8G6dKla3Ks9RIwxgaVGUTT%2ByQCTRS4MgfkvImAEYmIdv0jFho19uOyo2STMQSAEbs9RRENZMQIfSyqPzq6uDwB5%2Bzm0%3D%7Ctkp%3ABk9SR-SPp-eiYg

Martin

what diameter is the ram? Might be a runner if not overbig

21.3 mm

Sorry for the delay, this forums churns too fast for me!

Martin

I have one of the pumps in the above link which I use for testing the boiler on my 3" T.E and would consider it well over the top for Duncan, the one I use for my Stuart 500 boiler as a 12mm ram and keeps the boiler fed OK when supplying steam for a Stuart No9

H

like Harry I would consider 21.3mm rather too large for the job ! Noel.

Thanks for the info, I agree with Harry and Noel, I've started making a couple from scratch. I'm afraid I'm more into designing and making the bits than in owning the finished product practically everything I've made has been run enough times to eliminate the bugs, then put in a box for posterity.

just to show I do make something now and again, one for my latest loco, the other for the vertical boiler. Identical apart from the mounting bracket. Both have o ring clacks, I can never get balls to seat properly