Blackgates ( ex Southworth) 3" vertical steam pump

I am making good progress with this project, but have come to a halt with lack of dimensions on the steam chest. It is quite probable I am missing something obvious, so if anyone built one of these recently are they open to a question or two ?

Thanks in advance

Made four of them many years ago and am now making a further batch of three, any questions and I will try to help.

Edited By Baz on 18/07/2023 16:53:15

Many thanks Baz,

3 questions please:

1 The valve chest contains 2 valves, one driven off the piston rod and one ( the shuttle valve ) which appears to be self propelled using pressure from the ports.

On the steam chest drawing ( Item 2) , looking at the side elevation , the piston rod driven valve spindle is 0.165 from the cylinder face. But I cant see a dimension for the 0.156 diameter shuttle passage/hole from the cylinder face ? Is it the same as the other valve i.e. 0.165 centre from the cyl face - i.e. both valves the same centre line distance from the cyl face , or something different ?

2 Also on the cylinder (item 1) end view, for the end cap bolt pattern where it says 'copy the bolt pattern from item 5' , these undimensioned bolt patterns on the cylinder do not look the same as the dimensioned ones item 5, which are a simple 0.5" square ? On the cylinder they are not a square , one side appearing wider. I am very aware of the close proximity of the steam chest holding down bolts in this area.

3 How closely do you follow the depth of the 10BA holding down threads on the plan? They seem extremely shallow, the 0.075 cylinder end cap and valve chest holding down bolts for example.

Thanks in advance

Edited By GrahamS on 18/07/2023 17:18:53

Edited By GrahamS on 18/07/2023 17:19:33

Edited By GrahamS on 18/07/2023 17:20:21

Graham question 1 centre lines are the same, you are correct that drawing does not show shuttle valve centre line. Question 2 my drawing shows .230 centres, no way is that correct, what it should be is .230 either side of centre, .460 apart, the .500 dim is correct. The hole pattern is the same as item 6, a .650 pad. Question 3 I don’t, if your holes are in the right place the top / bottom holes will just miss the portface holes C on item 7. Make sure your shuttle valve is free to move, don’t use any liquid gasket, if you must use gaskets thin brown paper only and make sure all the holes are cut through, I don’t use gaskets all faces are rubbed on 600 grit wet or dry paper in fig 8 pattern until flat, couple of thou plus or minus on thickness won’t matter but not being flat will cause problems. Hope this helps, anything else just ask. These are lovely little pumps, they will go down to six strokes per min easily on about 35 psi, I use one on a small stationary steam plant as the only means of filling the boiler, apart from a hand pump.

May thanks Baz , very helpful. Thanks for the offer of future questions

I did a quick drawing to understand the cylinder end caps dimension issue.

So for both ends this seems right ?

If so luckily I only have to remake the top end cap as I havnt got as far as drilling the cylinder , phew.

Thanks