Author Topic: Globe valve and Handwheels  (Read 31095 times)

Offline smfr

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Re: Globe valve
« Reply #15 on: December 27, 2012, 01:19:44 AM »
And here is the valve - not finished yet, as you can see!

Oh, very neat looking, and with flanges! What happening on the inside? Is it something like this?



or just a quarter-turn on/off?

Simon

Offline tel

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Re: Globe valve
« Reply #16 on: December 27, 2012, 04:08:41 AM »
Yes, it's 'something' like that inside. I'll make an attempt at sketching what I did a bit later.
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Offline tel

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Re: Globe valve
« Reply #17 on: December 27, 2012, 05:17:56 AM »
Hopefully you will be able to make sense of this - any questions just holler.



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Offline smfr

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Re: Globe valve
« Reply #18 on: December 27, 2012, 06:54:04 AM »
Makes perfect sense, thanks tel! Is there any worry about only having a 1/8" passage for the steam? We seem to fret about steam pipe sizes, but then are quite happy to add valves with small apertures!

Simon

Offline tel

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Re: Globe valve
« Reply #19 on: December 27, 2012, 08:14:01 AM »
that 1/8" should be plenty, and is a good balance to form a head on the 1/4 x 40 screw for. Most, tho by no means all, of my engines have 1/8" steam pipes.
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Offline Firebird

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Re: Globe valve
« Reply #20 on: December 27, 2012, 10:47:43 PM »
Hi Simon

very nice indeed  :ThumbsUp:

Cheers

Rich

Offline smfr

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Re: Globe valve
« Reply #21 on: December 28, 2012, 06:25:56 AM »
I felt like having another try at the valve, so followed Jo's excellent advice and made a profiling tool. Boy, what a difference!

The tool started off as a bit of oil-hardening, ground stock, here marked out with a 0.25" radius and some hand-drawn joins:



I cut the primary radius with an endmill, then ground the smaller radii on the grinding wheel by hand, with final smoothing on a stone, then attempted to harden and temper it (which I don't think really worked very well; not hot enough). But it made quick work of the brass!



and the result is so much nicer looking:



I also took the advice about using an end mill to form the valve seat, which worked nicely:



I used one side of the same profile cutter to do the neck of the side-arm, so that it matched the body of the valve:



Here you can see that I've got a shim under the back of the profile tool. I didn't put any relief on the cutting edge, since I was afraid to ding the edge by grinding up to it. So a slight angle on the tool made up for that.

Other things I did differently this time: I broke out the 6" rotary table, which is easier to bolt down firmly (and a pleasure to turn, unlike the 4"):



and used an end mill for the side pocket:



It's a bit hard to see here, but there's no flare on the side arm. It drops into a pocket made with an appropriately sized drill (no collar required):



This worked nicely because it allowed me to put the solder on the inside, resulting in a much neater soldering job.

The other operations were the same as before, though I did learn that I have to adjust my BSB dies on the holder to get a good fit to the corresponding threads.

Here's the result (new one on the right), complete with with the gland nut. I stole the spindle from the first one, and still have to fix the disc to the spindle.



Next: experiments with hand wheels! I have three different styles on the go :naughty:

Simon

Offline tel

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Re: Globe valve
« Reply #22 on: December 28, 2012, 06:51:08 AM »
Nice work! Must find a bit of 'something' to make up a profile tool or three - save a lot of work.
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Offline Jo

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Re: Globe valve
« Reply #23 on: December 28, 2012, 07:24:28 AM »
I keep meaning to make up a set of small diameter profiling tools. One day :old:.

Jo
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Offline ScroungerLee

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Re: Globe valve
« Reply #24 on: December 28, 2012, 12:57:15 PM »
If you were to tilt the profiling tool blank a few degrees when you form the primary radius with an end mill you will get a relief on the cutting edge.

Lee
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Offline zeeprogrammer

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Re: Globe valve
« Reply #25 on: December 28, 2012, 01:24:07 PM »
That looks swell Simon.
Great post too. Very helpful.
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Offline tvoght

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Re: Globe valve
« Reply #26 on: December 28, 2012, 02:41:09 PM »
This is a really educational thread.

--Tim

Offline smfr

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Re: Globe valve
« Reply #27 on: December 28, 2012, 05:17:08 PM »
I keep meaning to make up a set of small diameter profiling tools. One day :old:.

I've been thinking exactly the same thing! I could use some for the handwheel radii! Should be pretty easy to do a batch lot. This time I'd hold the stock at an angle when drilling to get the relief on the cutting edge.

Simon

Offline Don1966

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Re: Globe valve
« Reply #28 on: December 28, 2012, 07:17:43 PM »
Nice work Simon I quess we all learned something off your post. Thanks for posting it.

Don

fcheslop

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Re: Globe valve
« Reply #29 on: December 28, 2012, 10:07:06 PM »
Nice work Simon, Old files are handy for making form tools simply soften them by heating and quenching they are also good for making gravers

 

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