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RWL1986
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Joined: Sun Aug 02, 2020 6:39 pm
First Name: Robert

New to me Double 72s

Mon Aug 31, 2020 1:15 pm

I picked up a set of Voit 72s yesterday from a Facebook marketplace. They are in very nice shape no rust or pitting. They also came with a Voit manifold that looks great. Last hydro was 1972 though and the tanks have a manufacture date of 1967. I’m hoping the inside is in good shape too but like all old tanks you just never know. The manifold will need to be rebuilt and serviced of course, has anyone any experience with Voit manifolds? Is it one of those things that is worth it or too much trouble for what it’s worth. I need to find a good hydro facility in the Chicago area that won’t look at me like I’m nuts for bringing them in too. Any tips or advice would be appreciated.
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swimjim
Master Diver
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Joined: Thu Mar 23, 2006 12:28 am
First Name: Jim
Location: Belgium WI

Re: New to me Double 72s

Mon Aug 31, 2020 2:00 pm

Sweet set of tanks! The manifold you could probably just clean up and use. I've used Dive Right in Scuba for things like dry suit repair and they seem to be pretty good folks. I don't know what their attitude towards Vintage is though. If you ever get up to the Milwaukee area 5 Alarm Hydro ( https://www.5alarm.com/category_s/1855.htm ) will take good care of you.

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RWL1986
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Joined: Sun Aug 02, 2020 6:39 pm
First Name: Robert

Re: New to me Double 72s

Mon Aug 31, 2020 3:51 pm

Milwaukee would work just fine for me, I head up there a few times a month so that’s perfect. Thanks for the tip just made my day

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antique diver
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First Name: Bill
Location: North-Central Texas

Re: New to me Double 72s

Mon Aug 31, 2020 3:51 pm

Many galvanized tanks have unfairly been condemned at the hydro test.

There is a special procedure for successfully hydro testing hot dipped galvanized tanks. Pressed Steel put out a bulletin some years back describing the procedure, but many hydro facilities and dive shops are still unaware of the special steps taken to prevent a false failed test. If you like I can email you the single page bulletin, and you can take it with you to a hydro facility. I would encourage you to go direct to the testing facility instead of depending upon a dive shop to pass the info on to whatever facility does their testing.

The schematic for your manifold should be available somewhere in the Manuals and Catalogs section of this forum. Link to that is very near the bottom of this page. If you can't find it I may have that in some of my files.
The older I get the better I was.

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antique diver
Master Diver
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First Name: Bill
Location: North-Central Texas

Re: New to me Double 72s

Mon Aug 31, 2020 4:01 pm

HERE IS THE MAIN PART OF THE BULLETIN MENTIONED ABOVE ABOUT TESTING GALVANIZED CYLINDERS:

P r e s s e d S t e e l T a n k C o . , I n c .
1445 South 66th St.
Milwaukee WI 53214
Ph: (414) 476-0500, Fax: (414) 476-9881
www.pstscuba.com
PST Technical Bulletin D100-E
Procedure for Hydrostatic Retesting of Hot Dip Galvanized Scuba Cylinder Revised 1/01/03
Steel scuba cylinders manufactured by PST must be re-inspected and retested at least every five years in accordance with the Code of Federal regulations
Title 49 CFR 173.34 (US) or CSA B339 (Canada).
This bulletin describes procedures that must be performed prior to retesting each cylinder. The cylinder must be prepared and test system checked in order
to obtain accurate results in the hydrostatic expansion retest for galvanized steel cylinders. All PST scuba cylinders made starting in 1952 are protected
from corrosion by a hot dip galvanized coating. This hot dip galvanized coating may affect the readings from the hydrostatic test, therefore failure to
prepare the cylinder and perform the test system check in accordance with this procedure may result in rejection of a perfectly acceptable cylinder.
Cylinder Preparation Procedure:
1. Remove the plastic boot.
2. Remove any crusty white corrosion deposits. Crusty deposits are most likely to form inside the removable plastic boot if the owner has not
routinely rinsed saltwater residue from this area.
3. Do not use aggressive acidic or caustic metal cleaners on the galvanized surface. The mottled gray-white appearance of used galvanized
cylinders is normal.
Test System Check Procedure :
1. Visually inspect the cylinder, fill it with water and place in the water jacket, as in your normal practice for any testing.
2. Zero the burette or expansion measuring system and pressurize the cylinder to 85% to 90% of the prescribed test pressure. Warning: DO NOT
EXCEED 90% [49 CFR 173.34(e)(4)(v)] of test pressure.
3. Hold the pressure and determine that the system is free of leaks.
4. Release the pressure to zero.
5. Zero the burette if necessary.
6. Proceed to retest the cylinder at the required test pressure.
7. Repeat this procedure with each hot dip galvanized cylinder to be tested.
This test system check procedure is specifically authorized under the provisions of 49 CFR 173.34 (e)(4)(v) and CGA C-1, Methods for
Hydrostatic Retesting, 1.4.
This procedure is necessary to obtain accurate test results. The provision of the PST Warranty therefore requires that the cylinders are prepared for
test and the system check is performed in accordance with these procedures.
The older I get the better I was.

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RWL1986
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Joined: Sun Aug 02, 2020 6:39 pm
First Name: Robert

Re: New to me Double 72s

Mon Aug 31, 2020 4:04 pm

The info the the proper hydro would be greatly appreciated and I am going to do the more direct route of right to a testing facility avoiding my LDS. Nothing against the shops around here but I don’t want to take a chance. I’m stopping in one today in Naperville IL for the first time and I’ll see what their feeling is to the vintage stuff.

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captain
Plank Owner
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Location: LaPlace, LA

Re: New to me Double 72s

Tue Sep 01, 2020 8:39 am

If the manifold operates easily and doesn't leak there is no good reason to overhaul it. Just replace the burst discs, and call it good.
Captain

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captain
Plank Owner
Posts: 1440
Joined: Mon Jul 04, 2005 11:32 am
Location: LaPlace, LA

Re: New to me Double 72s

Tue Sep 01, 2020 8:40 am

If the manifold operates easily and doesn't leak there is no good reason to overhaul it. Just replace the burst discs, and call it good.
Captain

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