Globe valve (how to make)

[gbritnell]

I see a very old thread was resurrected and I was going to try and edit it but the way the pictures and text were added it was really going to be a hodge podge of information so rather than do that I'm going to redo the thread. It will be a little more condensed from the original but should still get the job done.
First off here's the drawing for the valve.

View attachment VALVE SMALL.pdf

 

[gbritnell]

Gentlemen,
When I attend model engine shows some of them supply compressed air for the steam models, or air models as the case may be. For years I have had a little brass manifold with some aquarium valves on it. It works well enough but I decided I needed to class it up with some new valves, so five new ones were in the works. I know it's not a complicated build like making an engine but thought that there might be some who could gain from a photo essay. I started out drawing out what I wanted on AutoCad and then headed for the shop. First up would be the valve body. It would need to be a fabrication because of the shape. I have quite a few high speed steel forming tools that I have made over the years but I didn't have one for the body of the valve so I ground up another. I first roughed it on my bench grinder then with a small mounted stone in my Dremel I cleaned up the radius, matching it to my radius gauge. First I turned the .50 brass stock down to .36. Why not use .375 stock? I find that when using a forming tool everything needs to be as ridgid as possible, stock and tool, so I like to use larger stock to eliminate any chatter.
I then put in my small radius tool to do the blend radius at each end. I have a Trava-dial gauge on my lathe so I touched off to the end of the stock and moved over the required amounts, plunging in to the needed depth

 

[gbritnell]

Next came the drilling and tapping for the for the valve spindle tower. Not much explanation is needed here, just a couple of pictures.

 

[gbritnell]

Next it was over to the dividing head. I have a set-true chuck on my head so I indicated the stock to get it trued up. This chuck is very repeatable but the chuck on my lathe is .002-.004 out at times so I always indicate before cutting.

 

[gbritnell]

The hexes were then milled onto the body of the valve.

 

[gbritnell]

Next some more center drilling and then drilling for the right angle part of the valve.

 

[gbritnell]

After this step the piece was parted off leaving .01 for cleanup.

 

[gbritnell]

I then made up a 10-32 mandrel to mount the valve body on so that I could clean up the cut-off end and drill and tap the bottom.

 

[gbritnell]

The other end of the valve body was then drilled and tapped while mounted on the mandrel.

 

[gbritnell]

Next came a small bushing that would fit in the right angle piece and the valve body to line everything up for silver soldering. The bushing OD. was the tap drill diameter for the outlet piece. It only had a .006 wall

 

[gbritnell]

Here are several pictures with the outlet pieces pressed onto the sleeve.

 

[gbritnell]

Now it's out to the garage to do my silver soldering. I threaded the end of a piece of steel to mount the bodies on. I use steel because it doesn't transfer the heat as much as a piece of brass would. I only fluxed around the mating surface as everything was clean from just being machined. As the flux gets hot and turns liquid it wicks into the seam anyway. I have a full sized torch with a small tip but it's not small enough for some of the parts I make so a number of years ago I invested in a tiny oxycetylene torch by The Little Torch Co. It has 5 tips, the smallest being so small it's made with a ruby. Probably lasered in. I also had to buy the oxygen regulator for this torch because with the largest tip it only uses 5lbs of oxygen. The acetylene regulater works fine.

 

[gbritnell]

After soldering I boiled the pieces in water to clean off the hardened flux and then I put them into a glass bowl with a diluted mixture of water and sulfuric acid. I had read about this when building my traction engine boiler many years ago. I left them in the solution for about 2 hours. It doesn't make them shiny but it removes any burnt marks or traces of flux.

 

[gbritnell]

Next I made up the spindle tower, the valve stem and seat and the packing nut. The spindle thread is 1-72. It's made from bronze. I had to solder the seat onto the stem because I wanted an area with no threads so that the packing would have a smooth surface to seat against. Working with something this small doesn't allow for a larger screw thread than the spindle so you have to improvise.

 

[gbritnell]

Next came the handle. I wanted it large enough to get my fingers on but not so large as to look odd with the little valve. I layed out a pattern of 5 holes that would fit between the hub and the outside rim and have enough stock between them to still have some strength. I first turned the OD. of the stock, .613 and then relieved the face .01 out to the edge of the rim. The rim was formed with another ground forming tool. The radius is .03. I then put the piece in my dividing head and turned the head vertical. It was indicated true, offset the required amount and then drilled.

 

[gbritnell]

I drilled deep enough to get five pieces plus the width of the cutoff tool. No sense having to do this twice. After the first piece was cut off I made a split holder so that I could put it back into the lathe to face, recess and finish the rim on this side.

 

[gbritnell]

The final few pictures are of the assembled valve. I screwed the handle onto the spindle and then locked it in place with a .125 hex nut.

 

[gbritnell]

This is an addition to the original thread. I made the valves and then made a manifold to mount them on. As I stated at the start these were to run my steam engines on air at the model engineering shows. The manifold is brass and was a fabrication similar to the valves. I started with a piece of brass tubing cut to length. End caps were made to look somewhat industrial with the studs holding the end caps on. A handful of bushing were made and soft soldered to the tubing. The legs were lightened to add a little bit of character to them.

 

[gbritnell]

Here's some final pictures showing the valves mounted on the manifold. You'll notice some shim washers under a couple of the valves. These were made to align all the valves properly.
gbritnell

 

[Rudy from Norway]

Thanks for sharing! Beautiful litle valve.
I'm collecting inspiration and ideas to complete my Stuart 10V with a boiler.

Rudy