James
Lung Diver
Posts: 72
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

38s and post valves

Wed Jun 24, 2020 10:17 am

I am working on putting a pair of 1940s bushing 38s into service as singles for my 10 y.o. (my 72s are a bit heavy for him and the kid basically doesn't breath!). jrltenn was gave them to me (Thank you!) with a year left on the hydros, and new bushings, and a manifold (that will be set aside for when Ryan outgrows the 38s as singles).
Rob at The Scuba Museum hooked me up with 3 old post valves to try to rebuild (Thank you!). 1 Dacor, one Healthways, and one Superior. Taking them apart, the Healthways and Superior appear to be the same, and the Dacor is noticabley different. The Dacor is set aside for now due to a missing knob, nut, and stem thread damage. The Healthways I just got back together, and I have some questions... First being that I only get about 3/4 turn out of it from closed to as open as it will go. Is this normal, or am I not get enough range out of it to be fully (unrestricted) open? Secondly, has anyone found a source of 1800psi working pressure burst disks that works in these? I am going to try some paintball burst assemblies, but don't hold to high of hopes (ordered before I saw Surflung's threads referring to them not working).
I guess last question at this point, is does any one know of a pdf of Basic Scuba? I know it's the reference manual I probably need most, but can't find a copy that isn't hundreds of dollars as a collectible.
Respectfully,
James

User avatar
ScubaLawyer
Master Diver
Posts: 1649
Joined: Thu Apr 08, 2010 11:25 am
First Name: Mark
Location: Laguna Beach, CA

Re: 38s and post valves

Wed Jun 24, 2020 12:16 pm

As I recall I used 3000 psi burst disks (5/3 of 1800psi). Bryan may have them in the VDH store. Rob may have them at The Scuba Museum.

As for a .pdf of Basic Scuba I have always been perplexed by the copyright laws. I always believed that pre-1964 works are, for the most part, no longer subject to copyright protection, especially when no one is profiting off the reproduction. I have asked a bunch of copyright attorneys and the common response is a shrug. It would be awesome to have a high quality scanned copy of Robert's work available for everyone.
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

James
Lung Diver
Posts: 72
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: 38s and post valves

Wed Jun 24, 2020 1:58 pm

Thanks... All the 3k burst discs I can find are 3k working pressure (5k burst). I may end up going with 2015 working pressure discs (I gather it's a common pseudo solution).
In the meantime... are the old Superior/Healthways post valves a half turn valve? Or do I have something amiss with this one?

Thank you (all of you on this board) for the help. It's unreal how much I have gleaned from reading here, and how much help it is.

Respectfully,

James

User avatar
antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: 38s and post valves

Wed Jun 24, 2020 2:52 pm

James wrote:
Wed Jun 24, 2020 1:58 pm

... are the old Superior/Healthways post valves a half turn valve? Or do I have something amiss with this one?

Respectfully,

James
Something that I have seen causing that is the stem packing may be too thick to allow the seat to back out as far as it should. Is it Teflon or ?, and what is measured thickness of all the packing around the stem? Another thing that has occurred is someone having installed the wrong seat, with the replacement being longer overall than the original. Some photos of valve and the internals laid out may help one of us to think of something else.
The older I get the better I was.

James
Lung Diver
Posts: 72
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: 38s and post valves

Wed Jun 24, 2020 3:10 pm

I'll get it apart again tomorrow, and lay it out. There were the remains of an o-ring (I think) in it originally, so I replaced it with an appropriately sized one. I'm also not looking forward to disassembling it again, due to a dome shaped teflon packing that was a bear to get out, and had to be basically pressed back in (goes under the Bonnet nut. I can blow through it when open with about the same resistance as I get in a different valve that I have laying around, so I'm wondering if this is just how this valve is?

User avatar
antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: 38s and post valves

Wed Jun 24, 2020 3:37 pm

May not be worth the trouble to take the teflon out if you can determine the thickness and get a good photo of it in place.

Better idea before you open it up may first be to just take a photo of the whole valve. It may help me ID it to see if I have one like it I can take apart to see how it works. (lots of strange old valves in my barn)
The older I get the better I was.

James
Lung Diver
Posts: 72
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: 38s and post valves

Wed Jun 24, 2020 4:38 pm

Well, here are pictures of the one I assembled already (the Healthways) and a picture of the parts layed out (still need cleaned) of the Superior.
healthwaysValve.jpg
HealthwaysValveSide.jpg
SuperiorValveParts.jpg
I can't tell if the piece between the stem and the teflon (?) domed piece is a severely extruded O-ring, or a formed seal... but my I put an o-ring in that position when I reassembled the Healthways.
You do not have the required permissions to view the files attached to this post.

User avatar
antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: 38s and post valves

Wed Jun 24, 2020 7:03 pm

I think I still have one of the Superior valves like that. It has the old flat seal for the regulator instead of the later oring, but the other parts look familiar. I'll look for it and see what I can learn about the limited turns.
The older I get the better I was.

James
Lung Diver
Posts: 72
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: 38s and post valves

Wed Jun 24, 2020 7:12 pm

Thank you! Interestingly, the Healthways has the o-ring face seal, and the Superior has the old flat washer. Other than that, they seam to be parts interchangeable!

User avatar
antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: 38s and post valves

Wed Jun 24, 2020 11:32 pm

Found my Superior valve. Says Superior 5871 on one side and Healthways, Divair, LA California on the other.
It turns two full rotations. I'm guessing the new oring you put in took up enough space to account for one thread.

I'll try to get into it Thursday night and get some info to you.
The older I get the better I was.

James
Lung Diver
Posts: 72
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: 38s and post valves

Thu Jun 25, 2020 7:49 am

Bill,
You are amazing! Thank you for the help.
Further analysis of these valves: The one I reassembled did not have anything where I put the O-ring.... it just really looked like it should, and the one currently disassembled has that black rubber ring that either is a severely deformed O-ring, or a formed cup seal (my guess is deformed O-ring.) Both have the indent around the top of the lip on the stem where modern K valves put an O-ring followed by a Teflon washer.
I was hoping to get these assembled with confidence, and then bring the whole show to my LDS for visual and assembly.... but I'm starting to think I should put the bushing in one tank and use it to verify the valves with a few hundred psi, the disassemble it again for the LDS to do vis and assembly. I'm still waiting on an answer of if they will do assembly and fills on these, but they will definitely do a visual inspection, and if they won't fill them I'll just do assembly and transfil myself.
Respectfully,
James

User avatar
antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: 38s and post valves

Thu Jun 25, 2020 9:01 am

About the oring, some years back major valve manufacturer, Sherwood, started leaving the oring out (with no apparent change to the other internals). They began using one thin and one thick Teflon washer for the shaft seal. There was even a bulletin to that effect. That change proved to be effective and their widely used valves are still using the same combination.

Maybe we could use a similar combination in the Superior valves. I'm on the road for work today, but will check out some possibilities tonight if I can get home at a reasonable hour.

Thanks for the kind words. Glad to help. :D
The older I get the better I was.

User avatar
antique diver
Master Diver
Posts: 2210
Joined: Sun Dec 10, 2006 12:50 pm
First Name: Bill
Location: North-Central Texas

Re: 38s and post valves

Thu Jun 25, 2020 11:06 am

Business trip got delayed so I took the Superior/Healthways/Divair valve apart for inspection.

The Teflon sealing washer was not originally dome-shaped, but was flat like the one in photo. That dome shape deformation occurred during removal of the stem and seat as they were backed out, which was necessary to pull the washer out. I pressed the washer between smooth vise jaws in attempt to reshape it, but no luck. However that may not really present a problem, as explained below. (Unfortunately the flat one in photo is not a good fit on the shaft, and a little too large on the outside diameter, or I could just send it to you)

There was no oring on the valve stem, and the Teflon should have been entirely sufficient by itself in forming the pressure seal. Just like in the Sherwood valves mention in earlier post. Luckily this valve also is of the old-school design with an adjustable packing bonnet, which presses tighter against that Teflon seal the more you tighten it into the valve body. That sort of squishes the Teflon into a perfect fit around the stem and into the rounded groove around the stem end. So it it ever leaks you just tighten the bonnet a little more as needed, and that presses the Teflon back into a snug sealing fit.

There are a couple of fixes I think, both of which begin with removing the oring you added. For now don't worry about adding a small washer in place of that, as I don't think it's necessary.

1. You might find that the existing washer will smash down and seal even after the abuse of taking it out again and removing the oring.
Even though the Teflon is "self-lubricating" so to speak, you should also lubricate the shaft and seal with silicone grease. Tighten the packing bonnet securely.
2. There is a commonly available Teflon product that is like about a 3/32" diameter cord. It is used for making custom packing around difficult valve stem seals! You should be able to find it in the plumbing section at a good hardware store or something like Lowe's or Home Depot. You just wrap it tightly around the stem to fill the void about like the washer shape, but thicker than the washer because it will pack down more upon tightening the bonnet. Lubricate the shaft before wrapping but not necessary to lubricate the strand of Teflon.

I really think one of these repairs will do the job for you. If you need to correspond directly you can use my email link. Let us hear about your results.

I'm having trouble posting the photo I mentioned, but will keep trying.
The older I get the better I was.

James
Lung Diver
Posts: 72
Joined: Thu May 18, 2017 7:54 am
First Name: James
Location: Lower Alabama

Re: 38s and post valves

Thu Jun 25, 2020 11:29 am

Thanks again! I think I will reassemble the Superior with no O-ring, and put one of the tanks together to use as a test tank with a 300 psi or so before getting the visuals done, and try both (with and without O-ring) for good flow rate and leaks.
I'll update as I go.

User avatar
Vintagediver
Master Diver
Posts: 269
Joined: Mon Jul 11, 2005 7:28 pm
Location: Benzonia, Michigan

Re: 38s and post valves

Thu Jun 25, 2020 4:43 pm

James and Bill; the valve issue the two of you are dealing with brings back fond memories of a leaking Voit twin manifold some years back. Bill and I got the problem finally resolved; however to achieve that as each of us studied the schematics and posted back and forth I recall there was some rum and coke flowing in Michigan and so was the Bourbon in Texas; but we got er done!! :lol: :D
The friendship of many has been inspired and created while together we've explored beneath the waves the wonders of God's creation.

NAVED Member #137
Member of The 2016, 2017 Sea Hunt Forever Dive Team

Return to “Tanks and Valves”

Who is online

Users browsing this forum: No registered users and 9 guests