CrabbyJim
Diver
Posts: 21
Joined: Wed Apr 27, 2016 1:22 pm
First Name: James
Location: Olalla WA

Vintage tanks with sleeves

Thu Sep 15, 2016 10:25 am

I have a set of vintage 38's with 1/2 inch valves. One of the tanks has a sleeve to fit the valve to the tank. Local dive shops won't fill because of the sleeve. Does anyone know why? Are their safety issues? Antique Diver mentioned that he has experienced resistance to filling sleeved tanks but he has his own compressor. What's the deal with the sleeves?

On an another note, thanks to all of the VDH forum members for being so generous with their time and knowledge.

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Bryan
Plank Owner
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First Name: Bryan
Location: Wesley Chapel Florida
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Re: Vintage tanks with sleeves

Thu Sep 15, 2016 10:41 am

Information about cylinders with bushings.

viewtopic.php?f=41&t=8632&p=69852&hilit=bushing#p69852
Doing it right should include some common sense, not just blindly following specs and instructions. .Gary D, AWAP on SB

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captain
Plank Owner
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Location: LaPlace, LA

Re: Vintage tanks with sleeves

Thu Sep 15, 2016 10:09 pm

As long as the correct pressure rated bushing (it is called a reducing bushing not sleeve) is used
it is perfectly safe and legal.
Captain

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SurfLung
Master Diver
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Re: Vintage tanks with sleeves

Fri Sep 16, 2016 10:42 am

- I have three such "Bushing" tanks that I use regularly and four more I am restoring to make Twin 50s and Twin 38s. The ones that were already converted to scuba valves, I simply cleaned up the original bushing and re-installed it and the valve. I have a surplus "Shatterproof" USN oxygen tank I converted to Scuba... That one I ordered a new stainless high pressure bushing from that supply house that was referenced here on VDH.
- The only real drawback to the bushing tanks is that there's a lot of Teflon taped, tapered threads to have to disassemble and re-assemble every year if you intend to comply with visual inspections every year... Compound this pain in the neck when disassembling twin tanks. The hydro test on the other hand is only every 5 years.
- In the beginning, I avoided the expected hassle of dive shop scrutiny by simply cascade filling these tanks with a tank balancing hose. But with a fresh visual sticker on a twin 38 set, I have received fills from a dive shop a couple of times and was never denied.
- But cascade filling these makes a lot of sense ANYWAY:
First, because they are low pressure 1800 psi and they are valuable antiques that you don't want some dive shop to fill them up to 2500 or 3000 psi out of ignorance.
Second, because their low pressure makes cascade filling from modern 3000+ psi tanks very practical. It's essentially what the dive shop does when filling tanks from their storage bank.
- I dove the exact same set of Bushing Twin 38 Tanks for 9 dives at the Sea Hunt Forever event and simply refilled them from 5 other single tanks. Very slick! :)
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SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

CrabbyJim
Diver
Posts: 21
Joined: Wed Apr 27, 2016 1:22 pm
First Name: James
Location: Olalla WA

Re: Vintage tanks with sleeves

Fri Sep 16, 2016 11:50 am

Thanks for the very useful information in all of your replies. What I gather from them and information gathered elsewhere is that:
1. tanks with reducing bushings (thank you for the correct terminology, Captain, sleeves are for cylinders in engines) may legally be filled as long as they are within hydro.
2. Hydro testing includes a visual inspection but lds's usually require a current visual.
3. Removing the sleeve for visual inspection of the tank must be done with care to prevent damage to the bushing.
4. Bryan has posted a link (viewtopic.php?f=41&t=8632&p=69852&hilit=bushing#p69852) with some very helpful information.
5. Lds operators and employees may not be as well informed as the contributors to this forum, hence their reticence to fill these old tanks.

Please feel free to add to, correct or expand on this.

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