Voit Manifold?

[kworkman]

This is on a pair of Voit tanks, original hydro 5/61. I went through the Voit material on here for that year, but their manifolds look different. Of course the only markings on this are made in USA. Id like to know what I have and how to rebuild it. Thanks.

[SurfLung]

- Something wrong with that set up. It looks like a straight thread male going into a taper thread female and sealed with Teflon tape.

[kworkman]

Hmm. Now that is curious. I suppose I could take it apart and check it out. But now that you mention it, it does not appear that the threads go all the way up like a stand npt thread

[ovalis]

That's an early 70's Healthways manifold that can accept their "Air Flo" regulator.
They don't list if they made that manifold in 1/2" vs 3/4", but they were into 3/4" by 1965. I'm sure it's 1/2" because you wouldn't be able to get it into the tank otherwise. The only companies that made straight 1/2" thread valves that I can recall at the moment are Sportsways & White Stag.

[Bryan]

viewtopic.php?f=41&t=6854&p=58167&hilit ... ing#p58167

[antique diver]

Looks like a Healthways... at least the center section, since it appears to have the threaded outlet for their little oddball screw-in regulator they briefly offered. I think the whole valve was made by Sherwood for them. I have a couple of stand alone valves from Sherwood that look just like these, and yes they are 1/2" NPT type threads.

[kworkman]

Looks like Healthways starting offering their screw in regulator in 1969, but their threads were all 3/4 straight. Also the HP port is on the rear center piece instead of each valve like the other Healthways. Plus its missing the big H.

[antique diver]

A close look at my 2 valves indicate that they were originally the modern straight thread type, and had been re-machined after chroming to the 1/2" NPT. The chrome is missing where the larger threads were machined away. Apparently there was still enough demand for 1/2" valve that Sherwood made up some of these in the 70's. I bought them new direct from Sherwood in mid-seventies. At the same time I also bought some newly manufactured Sherwood 1/2" I-shaped valves made like the old 50's K-valves, but they had plastic top knob instead of the brass ones of the orginals. Also they are a little shorter than the USD k-valves. I still have two of those valves as well. I have used them in various pony bottles over the years, and liked them for their compact size.

As far as I can remember, Healthways seems to have been the only company to offer the valve with the internal threads at the outlet orifice for mounting that special compact first stage. Pretty sure that Sherwood made those for them, being about the largest maker of hp gas valves, long before they came out with their own branded dive gear. Of course your set could well be a mix-and-match setup.

To further confuse the ID of your valves, Sherwood also produced valves shaped like your two cylinder valves for Dacor, maybe some for Voit, and some for Nemrod USA. Could be others as well. The Sherwood valve kit sold by VDH should work fine in your valves. If not, let me know and I can probably find something in my box-o-stuff.

[kworkman]

Ugh who knows. I was wondering if it was possible that those threads had been machined down. If that is the case, I wonder if they kept it straight or made it NPT. If they are straight, what issues would I run in to if I taped the cylinder neck straight through? I probably wouldnt be able to get an oring seal on there would I?

[luis]

Ugh who knows. I was wondering if it was possible that those threads had been machined down. If that is the case, I wonder if they kept it straight or made it NPT. If they are straight, what issues would I run in to if I taped the cylinder neck straight through? I probably wouldnt be able to get an oring seal on there would I?

You can alter a valve, but you can not alter a tank. If you modify a tank in any way that affects it structurally (like modifying the threads) a hydro station is required to condemn it.

[antique diver]

Please don't re-invent the tank threads. There is no reason to try to change them to straight threads, and doing so will effectively destroy the tanks. They are 1/2" tapered for a reason, and that is a well established thread system that works just fine. Don't let some folks bamboozle you about the only good tank neck is the large o-ring sealed type. Yes, those are more convenient, but the tanks you have are fine the way they are.

When you pull the valves you will see that they are also the matching tapered thread. The further you turn them in, the better the seal. BUT, over-tightening can cause galling of the brass threads and possible damage to the steel neck threads.

Several wraps of good Teflon tape is necessary for a good seal. I generally use about 6 wraps. Some sources suggest less, but you won't cause a leak by having too much tape. May have a leak from too little. There is really no specific torque spec for NPT threads... unfortunately it's done by feel, and that just takes a little experience. It's hard to describe. If you are going to do it yourself, start with hand tight plus one revolution with a wrench. Maybe a little more if it feels loose. If it leaks, drain the air and then turn some more.

[kworkman]

Sounds good to me. I guess the first step would be to disassemble and see if they pass hydro and then go from there.

[antique diver]

Those cylinders are likely to be galvanized even if it has been painted over. There are some special instructions for hydrotesting galvanized cylinders that a lot of testers are not aware of, or do not follow. If not done this way galvanized cyls are more prone to test failure, so you may want to review the procedure, and maybe print it out for the testing co. Make sure they are willing to test in the specified way.

Go to the Manuals and Catalogs section and look for Cylinder testing or hydro information. It would be a shame to have these nice cylinders condemned due to improper testing. It's happened fairly often.

[kworkman]

Printed off the info and found the post about all the DOT testing facilities in my state. Now I just have to call around and see who wants to help me. Now does anyone have a tutorial for rebuilding that manifold or is it similar to the US Divers one that another user posted?

[kworkman]

Here are the full doubles. They do look like there is a coat of paint on them. I need to find a mate for the single.