Globe valve and Handwheels

[smfr]

Here's my first attempt to make a globe valve for my Stuart No. 4 (for the 5/16" inlet piping). I followed George's build here, http://www.homemodelenginemachinist.com/f31/small-globe-valve-how-make-4377/, but scaled it up 1.5X to better suit the size of my engine.

First step was to take some 5/8" brass and cut the profile for the main body:



followed by some freehand turning then filing of the globe:



I had a template to work to, but this was way off spherical which did cause some problems later. After this experience I'm eyeing one of the toolpost ball turners 

The next step was to drill through with a drill the diameter of the valve seat (the smallest of the diameters), then drill with the tap drill size down to the valve seat level, which is around the bottom of the globe. Then I used a small home-made boring bar to remove the angle left by the larger drill, leaving a flat around the valve seat:



The last step in this setup was to tap for the top, screw-in portion. I used the same thread for this as the pipe fittings (5/16" 26 TPI BSB). I suspect that a Model Engineer (ME) 32- or 40-TPI thread would be more appropriate, but I don't have taps or dies in that size.

Then came the screw-in cap part, which consists of a threaded end, a flange which will be cut into a hex, and a profiled neck:



I left drilling the center until I had it parted off, and then screwed into the body. That way, I know the bore is aligned with the body after assembly:



This cap is drilled through with the tap drill size for the thread used on the spindle (I used 5BA, and a 1/8" spindle), then drilled and reamed about half way down for the spindle. An external thread is cut on the end for the gland nut (I think I used 1/4" 26 TPI here).

The third part that makes up the body is the side arm, here being profiled to fit the globe:



While still attached to their parent material, the body is put in the rotary table to drill the side hole. I had a minor boo-boo here:



The rotary table wasn't securely bolted down, because I can't easily get a clamp on the front side. When cutting this hole, the drill caught as it broke through to the bore, and pulled the part up, tilting the rotary table up with it.  The result was a somewhat oval hole, but luckily it's covered by the side arm.

Then I cut the hex flats on both side arm and body:



A final small part is a collar which locates the side arm onto the body when soldering, so here's where we're at:



Here you can just about see the valve seat, which was, luckily, unmarred by the side-wall drilling incident:



The parts were then parted/hacksawed off their parent stock, and put onto a mandrel to drill and tap the newly exposed ends, as well as put a slight 30? profile on the hex flanges:



Time for silver soldering now! All fluxed and ready to go:



and post-solder:



That went into the acid bath for a while.

Not shown here was some threading of the spindle. I used 1/8" stainless steel for the spindle to avoid rust, and threaded the bottom portion 5BA, and a section at the top 6BA to give the handle a flange to sit on.

The handle started live as a bit of 1-1/4" brass bar. I left a generous boss in the middle to give me something to put in a collet later:



then trepanned out a bit from the lower face with a boring bar meant for internal threading:



While still attached, it was partially parted off, and the outer rim profiled:



then parted off completely, and flipped around and held in a collet to trepan the upper surface. I may cut holes or spokes at some point if I decide that this valve is a keeper.

So here's what we end up with:



which, when assembled, looks like:



It's missing the gland cap part that screws onto that top thread, which I haven't made yet.

Blowing through the valve while turning the handle indicates that it seems to form a pretty good seal.

Here's a trial fit on the engine:





I'm quite pleased with how the valve went together, but I'm not sure that it looks quite right on the engine. The globe part seems a bit small to me. Or maybe it's the mixture of styles of the lubricator, T-piece, copper piping and globe valve. It could be time to think about flanges everywhere   

So, things I'll do differently next time:

• Make sure the body is spherical. Preferably use a ball turner.
• Maybe give up on trying to profile the side arm to match the sphere. It would be easier to have it just be cylindrical, with just a solder fillet where it joins the sphere.

After this I also have questions!

• How the heck do you choose an appropriate thread for parts like this. So many choices! (BSB, ME, BA, English....). I *think* ME is most appropriate for mating brass parts like this, but 32 or 40TPI?
• What's the best way to get the valve bit fixed to the end of the spindle? Can I silver-solder stainless? Or maybe just center-punch the end of the spindle to lock it on?

Thanks for reading!

Simon

[Jo]

Simon,

Nice valve, your questions:

Ball turners will not help here, you have not got the clearance between the flanges. What you need is a profiling tool. A simple piece of gauge plate (or any bit of steel that you can later harden) drill a hole in it, shape up around the hole to suit your valve and harden, will work well

Threads: 40 TPI is normally chosen when you have an application where things have to line up.

Valve spindle: I am not sure what the problem is....Is it that the handle is threaded on and it is taking the nut off when you try to loosen the valve? This is why handles are normally mounted using a square on the shaft and secured with the nut.
-----
Edit: The trick for drilling the valve seat is to do that first on the round bar and then do the valve body profiling around the hole.

Jo

[Jo]

  Looking again at the photo's I have just realized the problem you have with the spindle: you have made the end separate to the spindle. It is normally all turned from one piece.

Yes go and silver solder it on. Careful with the flux stainless is a little different to SS and demands a higher temperature to take which is why they do a higher temperature flux (Tenacity) specifically for that job.

Jo

[Jasonb]

Like Jo I would go for 40tpi on these or 32 at a push. It gives you more turns of full engagement in a shorter length and also not having such a small root dia means you can get a larger bore to the pipe. And lastly on the ME series the tappings size is generally 1/32" smaller than nominal which means the often blind tapping hole can be drilled with a milling cutter to get a flat bottom without having to resort to small boring bars.

Regarding drilling the globe out, again a milling cutter to open out the dia would have been better than a drill plus ad some support to the overhanging end to stop it flexing and then snatching.

The spindle from solid would have been how I would do it but the equivalent to Tenacity or HT5 flux which removes the chromium oxide from stainless will allow you to silver solder it.

[tel]

The 40tpi ME series gets my vote as well

Nice job on the valve tho - really looks the part

[steamer]

I think flange connections would screw up the scale Simon.    The 4 has those 2 bolt flanges that would look way out of scale with a 4 or 8 bolt flange.

Right now it seems like a large model of a small engine...and looks right as far as I can tell
Maybe spoke and slightly dish the handwheel and put the bonnet gland on.....I think you've done a  great job!

Dave

[tel]

By sheer coincidence, I did a 180? flanged one last week - it's a bit bigger scale tho, 1" 'globe' and 8BA screws in the flanges. For your size you would need to go down to 12 BA perhaps, to get it looking right.

I'll try and get a pic tomorrow if I finish spraying early enough.

[zeeprogrammer]

Nice valve Simon. Excellent post too. I have a project in mind and found this very useful.

Re clamping the rotary table. When I did the hub for my spinning wheel the other day, it was the first time I'd used the RT in vertical mode. The whole thing flexed when I took a plunge cut. I added a long clamp to the top (side) of the RT down to the table to fix it. Don't know if this is the same issue you had or if this helps. (I should have pointed that out in my thread.)

[vcutajar]

Simon

Your engine is getting nicer and nicer.  I believe these small details make it stand out from the crowd. 

Vince

[Jasonb]

I think for the type of small launch engine that this represents then the screwed fittings look fine and certainly not out of place on an American installation where screwed pipe & fittings are more common. If it were a large marine engine then flanges would be better.

One thing I would say is the valve should probably be mounted with the spindle horizontal, that way it works like a stop cock and the pressure of the steam from the boiler will help to hold the spindle onto its seating rather than the steam trying to lift it off as you have it now.

J

[Don1966]

Looks good to me Simon, and I would add spoke to the valve handle. i would also do as Jason suggest and us the steam pressure to your advantage. I have the same problem with my RT and I put two clamps on the back side this helps greatly. Unfortunately the RT has no room to secure it on the front.

Don

[smfr]

Oooh, so much good information

Ball turners will not help here, you have not got the clearance between the flanges. What you need is a profiling tool. A simple piece of gauge plate (or any bit of steel that you can later harden) drill a hole in it, shape up around the hole to suit your valve and harden, will work well

Good point, though I was thinking something like this:



with maybe a 1/8" cutting bit could be used (with care!) for the final profile. I do have some some oil-hardening gauge plate, though, and a Dremel with a conical grinding wheel, so I can try that next time. I'm worried about chatter, though.

Threads: 40 TPI is normally chosen when you have an application where things have to line up.

Good to know! Time to stock up on ME taps and dies!

Looking again at the photo's I have just realized the problem you have with the spindle: you have made the end separate to the spindle. It is normally all turned from one piece.

Yes go and silver solder it on. Careful with the flux stainless is a little different to SS and demands a higher temperature to take which is why they do a higher temperature flux (Tenacity) specifically for that job.

The reason I didn't turn it all from one piece is that I don't feel confident that I can get a good, smooth accurate finish along a length of skinny rod. I should probably buy or make one of these:



George mentioned that he used bronze for this spindle. Any reason to choose that over SS?

Thanks for the feedback, Jo!

Simon

[smfr]

By sheer coincidence, I did a 180? flanged one last week - it's a bit bigger scale tho, 1" 'globe' and 8BA screws in the flanges. For your size you would need to go down to 12 BA perhaps, to get it looking right.

I'll try and get a pic tomorrow if I finish spraying early enough.

I would love to see that, tel!

After completing this valve, I found a reference to a German gent (store here http://www.modellbau-niggel.de/?sid=pn1440drsgp3cqibgeut49tot4) who makes smaller ones, like this:



which look like they'd be slightly easier to make. Gotta love the sand/bead-blasted finish, too. It's a bit odd that his direction arrow suggests that it should be mounted in such a way that the steam would be trying to lift the valve, though.

Nice valve Simon. Excellent post too. I have a project in mind and found this very useful.

Re clamping the rotary table. When I did the hub for my spinning wheel the other day, it was the first time I'd used the RT in vertical mode. The whole thing flexed when I took a plunge cut. I added a long clamp to the top (side) of the RT down to the table to fix it. Don't know if this is the same issue you had or if this helps. (I should have pointed that out in my thread.)

Probably; this is the little 4" table. I should make a clamp that extends out far enough to the sides that I can get in to tighten the hold-downs. Seems like we all have the same problem!

Simon

[tel]

Yes, some form of box tool is well worth the effort of making for jobs like the spindle. Mine is quite a simple affair, but works very well.

[tel]

And here is the valve - not finished yet, as you can see!

[smfr]

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

[tel]

Yes, it's 'something' like that inside. I'll make an attempt at sketching what I did a bit later.

[tel]

Hopefully you will be able to make sense of this - any questions just holler.

[smfr]

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

[tel]

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.

[Firebird]

Hi Simon

very nice indeed 

Cheers

Rich

[smfr]

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

Simon

[tel]

Nice work! Must find a bit of 'something' to make up a profile tool or three - save a lot of work.

[Jo]

I keep meaning to make up a set of small diameter profiling tools. One day .

Jo

[ScroungerLee]

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

[zeeprogrammer]

That looks swell Simon.
Great post too. Very helpful.

[tvoght]

This is a really educational thread.

--Tim

[smfr]

I keep meaning to make up a set of small diameter profiling tools. One day .

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

[Don1966]

Nice work Simon I quess we all learned something off your post. Thanks for posting it.

Don

[fcheslop]

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

[smfr]

Well, I spent most of the day twiddling the handles on the rotary table Tried various types of hand wheels for the valve, and some worked better than others. I didn't want to turn huge amounts of brass into swarf, so started with some disks parted/hacksawed off from a 1-1/4" bar, drilled 3/8" with a bit of cleaned 3/8" bar as a hub:



These were silver-soldered together (which I'm getting the hang of, I'm glad to say):



which gave me my starting material:



The solder joints are totally invisible on the final parts. This technique seemed to work well.

The basic procedure was some turning on the lathe on both sides of the part, cleaning up both the face and the hub of the exposed end, and doing whatever profiling on that face is required for the style of wheel. The hub was taken down to a diameter that I could hold in a collet later. For some, that required the pointy tool:



and for my third wheel style, which has a deep groove in the underside, a creatively-ground tool 



I then flipped the part around in the chuck; gripping the newly machined hub ensured good alignment.

Two wheels turned, with different rim styles:



I did a third blank with a more domed shape, here on the left:



After that came a lot of work on the rotary table, counting revolutions of the handle and trying not to screw up

The first handle had 6 holes drilled:



and then some edge sculpting with a 1/8" end mill:



I worked out the angles with respect to each 60? segment. So, for example, started at 0?, half of a projection was maybe 12? (with the same on the other end of the segment), leaving 36? of indentation. So we start by cranking the rotary table 12?, bring in the end mill, crank 36?, back out the end mill, then crank 24?, mill for 36? etc.

The domed wheel was turned with a deep groove on the underside, so milling slots would break through:



and again the edge was sculpted:



The third wheel had three spokes, so the end mill was plunged, crank for some fraction of 120? (accounting for spoke thickness and mill diameter), raise the mill, crank some more, plunge the mill etc. I also sculpted the edge of this one:



Here are the results:



I'm not super happy with any of them, but it was fun to make them!

The original wheel I wanted to form with three thin spokes. Alas, I had a brain fart when computing how much to crank on each plunge, and made a segment that was too big. I used the rest for spoke practice:



I made another blank to have a second try at spokes. This one was more successful:



but the spokes ended up too skinny 



Here you can see my notebook with my attempts at trig, and jottings for angles and hand wheel turns:



Maybe I can rescue the rim of that last one, and just solder in some spokes?

Now, I think I want to make something that doesn't involve fiddly bits of brass 

Simo

[steamer]

I like the one on the right!....13th photo down....

Dave

[Jo]

I like the one on the right!....13th photo down....

I like that one too.

Simon if you look at my E&A thread http://www.modelenginemaker.com/index.php/topic,393.0.html reply 7 I mentioned how I make hand wheels with thin spokes. It may give you a little inspiration.

Jo

[zeeprogrammer]

I like them all.
Now I'm interested to see what you're going to build to attach them to. 

[gbritnell]

Outstanding work on the handles. These will surely dress up a valve. I like most of the designs but am partial to the first and third in the one picture of three.
gbritnell

[NickG]

Nice work, I like the one on the left of the three but with smaller holes drilled. 

[Firebird]

Hi Simon,

I'm really liking this 

One question is the oil hardening ground steel plate also known as guage plate?

cheers

Rich

[Jo]

One question is the oil hardening ground steel plate also known as guage plate?

Yes

[Firebird]

Thanks Jo

Cheers

Rich

[Don1966]

Simon I love all of them, that was some excellent demo's thanks for posting.

Don

[Steamer5]

This thread just gets better & better! Thanks Simon for starting it & to all who have added to it.

Here's another idea.  Dad brought a loco some years back. After running for some time he had one of the blackhead valve spring a leak. The guy who he brought it from had made up new ones, but hadn't assembled them, he had made them from stainless as well. So how to hold them together & aligned while silver soldering, well we just happened to have some carbon rods, so 1/4" one was chucked up & urged to a neat fit in the bits, fluxed soldered job done, & if the carbon doesn't drop out its very easy to brake up& remove. Hope this is of use to somebody, as it sure worked for us.

Merry Xmas & have a happy & safe New Year

Cheers Kerrin........
Now back to the workshop to put the mill nback together ( that's another story)

[tel]

  on the carbon rods - I've been known to pull the cores out of D cells and machine that to fit. Works a charm.

[smfr]

I'm not picturing how the carbon rods are used. Do you mill a pocket in the rod to keep the parts being soldered aligned? Or make a "spindle" from carbon for the same reason? Does the carbon burn away on soldering, or just survive the heat?

Simon

[zeeprogrammer]

I'm not picturing how the carbon rods are used. Do you mill a pocket in the rod to keep the parts being soldered aligned? Or make a "spindle" from carbon for the same reason? Does the carbon burn away on soldering, or just survive the heat?

I'm interested in knowing that too. Pics would be very helpful.

[tel]

They are used in existing holes, to keep said holes in alignment and clear of solder during soldering.
Especially useful when you are joining oddly shaped bits - like my Rocking Valve engine cylinder (attached)

[smfr]

After far too long out of the shop becaue of work commitments I've finally had a chance to go through a backlog of pictures, and get a bit of shop time!

I'm know I'm picking up a really old thread here, but I think I finally managed to make a steam valve that I'm happy with! Rather than the hex flanges, I decided to go with rounded flanges the match the profile of the PMR pipe connectors I'm using.

As before, I used a form tool to cut the body and that worked quite nicely:



and with another form tool for the end flanges, I got this:


The body was drilled and threaded as before, and a small boring bar used to clean up the valve seat:


Then into the rotary table to hold it sideways to create the recess for the side-arm, which was soldered in:


The rest of the body was done as before.

Now back to handwheels!

After the earlier experiements, I wanted to refine two of the designs, so two disks of brass were parted off and soldered onto a core, as before:


then the center part thinned out with the trepanning tool:


This time I used a form tool for the outer circumference, which gives a nice round profile:


The first wheel I wanted to have 5 holes, so that was some quick work on the rotary table:


The second wheel I left solid. Now, to attach the wheels to the spindle, I wanted to have a square hole in the wheel fit onto a squared shaft. So, I thought, let's make a broach!

Some oil-hardening drill rod, after being turned down to a diameter just over the diagonal size of the desired square. I've drilled down the center, and am using a countersink to leave a sharp edge:


and then it was squared off in the rotary table (really need to get myself an ER-32 collet block!):


Here are a couple, at different sizes, after my attempt at hardening and stoning. They look pretty good!


However, the results say otherwise 

Trying to broach one of my earlier handwheel attempts actually broke the spokes, and examination of the broach showed that it was nowhere near hard enough; those points bent all over the place!


Good thing I didn't try it on one of my final handwheels 

It seems like I haven't got this hardening thing down yet. I did hold the part for a good few minutes at cherry red, and quenched in oil (vegetable oil snuck out of the kitchen cabinet  ), but I think I need to do the magnet test in future.

So I ended up just filing a square hole in the chosen handwheel with a square needle file, which worked fine. The valve spindle was squared off in the rotary table to match.

Here are my final parts, on the right:


On the left there is a valve from a Stuart 501 boiler. It's funny; throughout most of this valve-making experience, I was hindered by lack of a model to copy. Yet sitting at the back of the bench is this boiler, with a very similar valve sitting on top 

For my later attempt at this valve, I used the more proper design of spindle, where the threaded section has a larger diameter than the rest (which is 1/8"), allowing the valve to be assembled in the conventional way. The spindle is stainless. You can see the square end of the spindle, and matching hole in the handweel. The other valve parts aren't too hard to make; just some turning, threading, and cutting of hex in the rotary table. The only part that caused me trouble was getting the "hat" to screw down far enough, which required cutting some relief behind the theads with a tiny boring bit ground from an old broken endmill.

After that long saga, here's the final valve mounted on the Stuart No. 4. I think it'll do for now!



Simon

[Jo]

Very nice Simon 

Jo

[tel]

It is, isn't it! Really looks the part!

[Ramon Wilson]

Very nice work Simon, as Tel says it really looks the part.

If I could mention a couple of things found in broaching such over the years .

Your broach design will mean the swarf will tend to push into the cutter and can crowd. It's  much better and more effective to make the end flat and square to the length. ( if you can grind it square to the periphery of a grinding wheel it will give a slight concave surface in one direction - this can help on larger sections but is not essential)  Drill the hole about .1 - .2 mm larger than the across flat dimension - this still leaves plenty for the broach to take out but relieves the pressure on the part (and the broach) enormously. It doesn't produce a full square hole obviously but does give more than enough drive in the corners) Also where ever possible make this the first op ie  using the tailstock do the hole in the lathe first before turning any shape as this not only provides maximum support but the hole can be deeper than required so 'break through' damage is avoided.

Re the heat treament. I feel I've made enough comment on this on here but I can honestly say in all the time involved with this I've never heard anyone using a magnet to test a red hot metal parts When you have the part to that stage it's time to quench it quickly - and especially small parts. I've never used vegetable oil and can't see any reason why not but old motor oil will do just fine however.

As you describe the results you have it sounds like the material possibly wasn't heat treatable - cut a slice off and try again just as you have described doing it - check the result with a file - you'll quickly tell if it's hardened. You won't be the first to be caught out trying to heat treat 'precision ground mild steel' 

Lovely work
Good luck with the rest

Ramon

[steamer]

I agree with Ramon, Check the material Simon, I know I've done that!

Awesome Job man!....and welcome back!

Dave

[b.lindsey]

Nice to see you back at it Simon, and the valve turned out amazing!!!  Great pictures too.

Bill

[RonGinger]

What timing! I woke up this morning and while thinking about what to do today I decided I would make a valve and pipe and mount my Stuart #4 to a show base. I have been working on finishing the reverse gear for a while now. I built the engine years ago, then found the reverse kit at some show.

[smfr]

Very nice work Simon, as Tel says it really looks the part.

Thanks Ramon!

You won't be the first to be caught out trying to heat treat 'precision ground mild steel' 

  That might be exactly what I did. Need to keep my stock better labeled! Now, of course, the inevitable question is how can I distinguish between O1 and mild steel rod? A spark test?

Simon

[smfr]

What timing! I woke up this morning and while thinking about what to do today I decided I would make a valve and pipe and mount my Stuart #4 to a show base. I have been working on finishing the reverse gear for a while now. I built the engine years ago, then found the reverse kit at some show.

Ooh, neat. Would love to see some photos, especially if you've painted it. I just started some prep for painting the base of my Stuart last night, and I'm really not sure how far I need to go with the pre-painting smoothing.

Simon

[Alan Haisley]

The valves and wheels just keep getting better.

[Ramon Wilson]

  That might be exactly what I did. Need to keep my stock better labeled! Now, of course, the inevitable question is how can I distinguish between O1 and mild steel rod? A spark test?

Simon

You'll get a noticeble (spark) difference betweeen the two but the easiest way is to just cut a thin slice off both - heat treat them then mark up the stock the hard bit came from  - if you're not absolutely certain of the material  taking a slice off and heat treating it is always a good thing to do before making a part requiring heat treat anyway

Regards - Ramon

[Marinus]

Looking nice Simon   Today I just had to make a D-bit to complete TICH's coupling rods. You can even get some reinvorcing rods that they use to reinvorce conctere buildings. First I got some mild steel bar and turned the D-bit and heat treated it in oil (This didn't work) and then I took some reinvorcing rods and turned the D-bit and heat treated it and threw it in cold water when red hot. This worker very well, and this can even work for a centre punch

[PeterE]

Hi Simon,

First I want to say that the globe valve turned out very nice, really good work! 

Then an idea for a broach to make the square hand-wheel holes. I picked this up from GHTs Model Engineers Workshop Manual and it sounds very useful so I thought it may be of interest.

Instead of trying to bite the whole corner (all 4) at one go, make a tapered square broach looking somewhat lika a step drill but with straight saw tooth profile to the teeth. The taper should be slender to give 10 to 12 teeth. The thin end is made as a guide tip fitting the start hole.

The broach made from silver steel/drill rod and hardened.

Hope this can work.

BR

/Peter

[vcutajar]

I know this thread is a bit old, but I am reviving it because I have a question I would like to ask.

In my search for a simple valve to make for my current project I came across a diagram that Tel posted on page two of this thread.

In this diagram which I am reattaching, which is the inlet and which is the outlet?

Vince

[Don1966]

I know this thread is a bit old, but I am reviving it because I have a question I would like to ask.

In my search for a simple valve to make for my current project I came across a diagram that Tel posted on page two of this thread.

In this diagram which I am reattaching, which is the inlet and which is the outlet?

Vince

Vince I would say the top part is the inlet. You want the pressure pushing the stem seat down not out.

Don

[vcutajar]

Thanks Don.

Vince

[sshire]

Simon
Not sure how I missed all of the fun here but, this thread (and your valves) must be a keeper. A wonderful class on globe valve making.
Love it.

[Dan Rowe]

I know this thread is a bit old, but I am reviving it because I have a question I would like to ask.

In my search for a simple valve to make for my current project I came across a diagram that Tel posted on page two of this thread.

In this diagram which I am reattaching, which is the inlet and which is the outlet?

Vince,
The rule of thumb for a globe valve is the gland is on the outlet side of the valve. This is done so when the valve is shut off the gland packing is not under pressure. See the diagram in post 15 to see the usual arrangement of a globe valve.

Dan

[vcutajar]

Thanks Dan.  I see what you mean.

Vince

[Dan Rowe]

Vince, Looking at the drawing provided by Simon in post 15 shown here:



There are two valves made to the same pattern. If the stem is the same part as the disk or if they are fixed together it is a stop valve.

If the disk is not fixed to the stem and the stem only acts as a guide to center the disk then the valve is a stop check valve and it will only open if the inlet pressure is higher than the outlet and of course the stem is in the up position. The stem can only shut the valve.

The only way to tell the difference between a stop valve and a stop check valve is to look inside and check if the disk is fixed to the stem. The casting on a full size valve will have an arrow but it points the same direction on both types of valves.

On the ships we usually had a bucket of valves that needed repair. It was always the job left for when there was nothing pressing to do.

Dan

[derekwarner]

Another point here for model valves is if the constrained disc floats on the stem.....then the degree of alignment is not as critical

I purchased a 1/8" steam stop valve from a reputable British manufacturer which leaked steam @ 3 Bar...inspection confirmed a one piece stem/disc construction but with some eccentricity as the disc confirmed only approx. 75% witness marking.......

The manufactured protested this could not happen  .......however finally provided a FOC replacement valve [& a few fittings to boot] after digital images were offered & the return of the valve from OZ to UK...as the return APP cost back to UK was approx. 33% the cost of the valve........ Derek

[Don1966]

Dan appreciate you clearing that up and thanks for the diagram.

Don