Duplex steam feed pump

[John RutzenParticipant @johnrutzen76569]

Hello, i've been looking for a design for one of these and seen photos of one made by J L Austen-Walton. I can't find this in the M.E. index though I do see that the drawings are available. Can anyone tell me the reference please?

[John RutzenParticipant @johnrutzen76569]

[Clive Brown 1Participant @clivebrown1]

Was the pump part of the "Twin Sisters" design, in which case it is in ME vol.100, 1949I believe?

Are you aware of the LBSC design in "Shop, Shed & Road"? He gives quite a detailed description of its construction, useful as it looks to be quite a complicated little beast. It can be built without castings, but I've not made one so can't really comment.. Maybe a bit on the small side for, say, 5" locos as LBSC tended to favour the smaller gauges.

[Bob WorsleyParticipant @bobworsley31976]

This is the Weir type pump?

Yes, LBSC did several versions of this in the 40's and 50's, can get castings from Kennions.

They look a wonderful thing to start model engineering with, much smaller, cheaper and simpler than a loco like Tich.

[duncan webster 1Participant @duncanwebster1]

The LBSC 2 cylinder pump is a version of the Worthington Simpson, where the valve for one cylinder is operated by the other cylinder. See pump. Instead of the reversing levers the little version has complicated cross drillings to send the steam where it's wanted. This type seems a lot less finicky and more liable to work in small size than the Weir type which has a steam operated shuttle valve. I you want the Weir type then Southworth engines did castings but their website doesn't work anymore

[Paul LousickParticipant @paullousick59116]

There are models of steam operated boiler feed pumps on Grabcad.com and are free to download.

Worthington Steam Pump – Utilizing a slide valve, directly linked to the pump piston. Files are in STEP format and can be imported into most 3D CAD packages.

Youtube video **LINK**

**LINK**

Or a Stuart Boiler Feed Pump which has a hydraulic shuttle valve, a more reliable way of reversing the pump direction. Files are in Solidworks, STEP and Stl format.

**LINK**

[JasonBModerator @jasonb]

Blackgates now do the Southworth range.

[John RutzenParticipant @johnrutzen76569]

Thanks everyone. I'll look up my old M.E. volumes, I have some of the twin sisters articles, I just couldn't see any reference to the steam pump in the index. I'll also check out that Grabcad thing.

[John RutzenParticipant @johnrutzen76569]

Paul, I've downloaded those files from Grabcad but I can't open them. My computer is Windows 10 Pro. Can you suggest what's wrong please?

[Paul LousickParticipant @paullousick59116]

Hi John,

They are 3D CAD files and you need suitable software to open the models, then you can create drawings.

Castings and drawings are available from Stuart Models https://www.stuartmodels.com/product/steam-boiler-feed-pump-unmachined/

Edited By Paul Lousick on 02/11/2022 09:16:52

[John RutzenParticipant @johnrutzen76569]

Thanks Paul. going back to the Austen Walton pump I've found it is described in volume 103 , 1950. Does anyone have that please? Would it be possible to get a copy of the relevant article? Thank you. I have volumes 102 and 104 and there is a picture of it in volume 104 and he says it was recently described so I am assuming it was in volume 103.

[Paul LousickParticipant @paullousick59116]

Sarik Hobbies sell plans for a J L Austin-Walton twin cylinder, double acting steam pump for £13.00

**LINK**

[Martin Johnson 1Participant @martinjohnson1]

I did an adaption of the big Southworth single to make it more robust and less prone to leaks. Pm me if you want drawings.

Construction described on my Flickr account here:

If it must be a twin, go for the Worthigton type shown in Paul's post. No crossover passages in the block so less condensation.

I have seen loads of the Stuarts, but not many run, so it seems. The Lbsc one is watchmaking.

A few tips:

Feed it with SUPERHEATED steam.

Include a bypass back to the water tank so you can get it warmed through on no load.

Include those little self acting cylinder drains, also at any low spots in the supply line. (Frèe ball in a housing.

Feed plenty of cylinder oil, or it will jam solid for next time. DAMHIK

I think the twin is probably more efficient as there is no steam used just to work the valve but two cylinders will be smaller than a single, hence more condensation.

Hope that helps,

 

Martin

Edited By Martin Johnson 1 on 02/11/2022 13:19:10

[Clive Brown 1Participant @clivebrown1]

Here's a Stuart pump running on air. It's a bitfast, i would hope it would slow down if actually pumping against boiler pressure.

[John RutzenParticipant @johnrutzen76569]

Hi everyone, thanks for the feedback. I've found the Austen-Walton article at last! A friend who lives locally had a load of old volumes and I found it among them.

[duncan webster 1Participant @duncanwebster1]

Having had dome arms length involvement with steam air pumps, the duplex ones just work, the shuttle valve ones are touchy. Does the Austen Walton one have the reversing lever or cross drilling?

[John PurdyParticipant @johnpurdy78347]

John
Many years ago I came by some boxes of assorted locomotive castings including a part built duplex steam pump. I have often wondered whose design it was with the thought of finishing it. Now looking at the link provided by Paul it looks like it might be Austen-Walton's from Twin Sisters. Which issues of ME was it described in? If you could check, some dimensions of the pieces I have are: top and bottom plates: 3" x 1 3/8", Cylinders (steam and pump ) 1" dia x 1" long, overall height of cylinders and spacer less top and bottom covers 3 1/4", valve chest 1 1/4" x 1.175".
John

[Martin Johnson 1Participant @martinjohnson1]

Posted by Clive Brown 1 on 02/11/2022 14:38:23:

Here's a Stuart pump running on air. It's a bitfast, i would hope it would slow down if actually pumping against boiler pressure.

Ah yes, now run it on steam delivering against boiler pressure……….

Martin

Edited By Martin Johnson 1 on 03/11/2022 13:05:33

[Clive Brown 1Participant @clivebrown1]

Hi Martin, are you suggesting that it would slow to a more relaxed pace, which I'd hope for, or just stop altogether? I haven't yet got round to connecting it to a boiler, but at its present speed it wouldn't take long to fill it to the brim.

[John RutzenParticipant @johnrutzen76569]

Hi John, yes that is the Austen-Walton one. I now have the articles , they are in October 12th and October 19th 1950 issues. The top and bottom steel plates are very distinctive.

[John PurdyParticipant @johnpurdy78347]

John
Thank you for the conformation and the dates of the articles. Now to find the articles. My MEs only go back to '79 but my club library has a pretty complete set, but that's 250 km away. I'll have to check next time I'm down there, probably next summer.
John

[John RutzenParticipant @johnrutzen76569]

They are in volume 103, there is the complete volume of ebay for £12 including post at the moment.

[Paul LousickParticipant @paullousick59116]

My Ruston Proctor traction engine from LSM came with a steam operated Moore Pump which I stopped building because I realized that it would not work. (also reported by other builders). It is a single cylinder pump with a slide valve, directly coupled to the piston rod.

Slide valves on engines work OK because the inertia in the flywheel carries the valve past the mid point where both steam ports are closed but on a slow moving pump the valve can stop moving, covering both supply ports.

Duplex pumps like a Worthington have 2 cylinders in which the piston on the RH side operated the slide valve on the LH side and when it has finished its stroke the opposite happens. A hydraulically operated shuttle valve is a similar design.

I am in the process of adding a shuttle/change over valve to the pump which I already have.

[John RutzenParticipant @johnrutzen76569]

That's very interesting to know Paul. There are many drawings out there for bits that don't work, it's very frustrating at times.

[Martin Johnson 1Participant @martinjohnson1]

Posted by Clive Brown 1 on 02/11/2022 14:38:23:

Here's a Stuart pump running on air. It's a bitfast, i would hope it would slow down if actually pumping against boiler pressure.

It will slow down under load, in fact it should run quite nicely on just a few pounds of air. The clever bit is getting it to run on (usually soaking wet) steam. A couple of turns round the smokebox is unlikely to give enough superheat.

Martin

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