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Clanggedin
12-27-2007, 12:20
I recently aquired a small steel tank from my father-in-law. I believe it's an HP80 tank since it is smaller than the AL80 tanks he has and says 3500 instead of 3000.

It's last Hydro was 1-91'. There is still air in it and there is no vis sticker on it. I don't see any signs of rusting at all and the tank appears to be in very good condition.

I know steel tanks can last longer than Aluminum tanks, but could this one still have life in it??

CompuDude
12-27-2007, 12:27
Absolutely. Just take it to your LDS. You'll need to spend a little money on it to get it running again, since it needs a hydro test (~$25) and a visual test (~$10) before anyone will fill it, but steel tanks can last for many, many decades as long as they don't get water inside (and thus rust).

WD8CDH
12-27-2007, 14:19
If it is 3500psi and not 3442psi or below, then the neck thread is probably 7/8"UNF not 3/4" NPS. That will limit you to 300 bar DIN valves and regulators and no yokes.

CompuDude
12-27-2007, 14:24
If it is 3500psi and not 3442psi or below, then the neck thread is probably 7/8"UNF not 3/4" NPS. That will limit you to 300 bar DIN valves and regulators and no yokes.

If it's from '91, that's probably the case. It'll be DIN-only. Great excuse to convert your regs to the more reliable, more universally compatible (with an inexpensive adapter, at least) DIN format!

MSilvia
12-27-2007, 14:29
Age shouldn't be a problem. I still use a couple of steel 72s that are 25+ years old.

Clanggedin
12-27-2007, 14:43
If it is 3500psi and not 3442psi or below, then the neck thread is probably 7/8"UNF not 3/4" NPS. That will limit you to 300 bar DIN valves and regulators and no yokes.

It has a Sherwood 6300 DIN valve on it. I was planning on going DIN anyway, since that is what my brother's reg set uses currently.

In the pocket of the US-Tech BCD that was still attached to it, there was what appeared to be a DIN to Yoke adapter, but it is threaded for a small DIN type valve than the one on my tank.

Are there different sizes of DIN valves? The adapter I have was made by Scubapro. It just slides in the valve it's so small.

When you say 300 bar regulators, do you mean they just need to be DIN or do I need to get regs that run on a higher PSI like Poseidon regs?

BSea
12-27-2007, 15:14
If it is 3500psi and not 3442psi or below, then the neck thread is probably 7/8"UNF not 3/4" NPS. That will limit you to 300 bar DIN valves and regulators and no yokes.

It has a Sherwood 6300 DIN valve on it. I was planning on going DIN anyway, since that is what my brother's reg set uses currently.

In the pocket of the US-Tech BCD that was still attached to it, there was what appeared to be a DIN to Yoke adapter, but it is threaded for a small DIN type valve than the one on my tank.

Are there different sizes of DIN valves? The adapter I have was made by Scubapro. It just slides in the valve it's so small.

When you say 300 bar regulators, do you mean they just need to be DIN or do I need to get regs that run on a higher PSI like Poseidon regs?I'm not sure what adapter you are talking about. It might be a fill adapter so you can get your tank filled from a shop that doesn't have a din fitting.

There are 200 & 300 bar DIN valves. But you don't have to have a poseidon to use a 300 bar. Any din regulator should work. For more info on the differences between 200 & 300 bar, look HERE (http://www.diveriteexpress.com/gas/thermo.shtml). It explains it about half way down the page.

CompuDude
12-27-2007, 15:41
If it is 3500psi and not 3442psi or below, then the neck thread is probably 7/8"UNF not 3/4" NPS. That will limit you to 300 bar DIN valves and regulators and no yokes.

It has a Sherwood 6300 DIN valve on it. I was planning on going DIN anyway, since that is what my brother's reg set uses currently.

In the pocket of the US-Tech BCD that was still attached to it, there was what appeared to be a DIN to Yoke adapter, but it is threaded for a small DIN type valve than the one on my tank.

Are there different sizes of DIN valves? The adapter I have was made by Scubapro. It just slides in the valve it's so small.

When you say 300 bar regulators, do you mean they just need to be DIN or do I need to get regs that run on a higher PSI like Poseidon regs?

The DIN-to-yoke adapter goes on your regs, not on the tank. That's so you can borrow someone's Al.80 and still dive it with your DIN regs.

Unless, as above, you're talking about the fill adapter. That's just a temporary fitting for surface use only, and goes directly into the tank's valve for fill whips that only have Yoke connectors.

These two pages have the best info I've seen on DIN v. Yoke:

uk.rec.scuba : UKRS Dives (http://www.ukrecscuba.org.uk/ukdiver/dinyoke.htm)

DIN Scuba Fittings (http://www.nigelhewitt.co.uk/diving/din.html)

Clanggedin
12-28-2007, 10:47
The adapter that I assumed was a DIN to Yoke is actually the yoke section of a Scubapro 3000 first stage.

Thanks for all of the great links about DIN adapters.

kancho
12-28-2007, 14:50
When would u use a 200 Bar or 300 Bar Din Valve? 200 bar is about 3400 psi right?

CompuDude
12-28-2007, 15:20
When would u use a 200 Bar or 300 Bar Din Valve? 200 bar is about 3400 psi right?

Makes no practical difference for normal tanks commonly used today. Either is just fine. The bigger difference is the DIN connector on the first stage. The good news is 300 bar on the reg side is standard today, and works with either. The ~200 bar DIN connectors were only used on some regs quite a long time ago, so if you're using current gear, you can be assured everything will work together just fine.

In sum: 200 or 300 bar on tank valve: works with all current gear.

200 bar on first stage: Not very good, but very rare.

300 bar on first stage: Perfect, works with all, both 200 and 300.

WD8CDH
12-31-2007, 16:01
The 200 bar DIN (also called 232 bar DIN) is really just as trong as the 300 bar DIN. DiveRite rates both at 4500psi with their valves. The real reason for the difference is so you can't put an old 200 bar regulator on a 300 bar tank.

If those tanks are 3500psi and the small thread, the only reasonable way to put a yoke regulator on them would be to get a 300bar modular valve and put a 232 bar "H" valve on the side with a yoke insert. Many yoke regulators (even some old double hose regs) are rated for at least 3500psi.

Cousteau even used yoke style double hose regulators at 5000psi.

CompuDude
12-31-2007, 20:04
The 200 bar DIN (also called 232 bar DIN) is really just as trong as the 300 bar DIN. DiveRite rates both at 4500psi with their valves. The real reason for the difference is so you can't put an old 200 bar regulator on a 300 bar tank.

If those tanks are 3500psi and the small thread, the only reasonable way to put a yoke regulator on them would be to get a 300bar modular valve and put a 232 bar "H" valve on the side with a yoke insert. Many yoke regulators (even some old double hose regs) are rated for at least 3500psi.

Cousteau even used yoke style double hose regulators at 5000psi.

MANY yoke regs are rated for 3500 psi, but not all. I'd wager that anything made in the past 10 years, certainly, will be fine for 3500 psi, but with older yoke regs you may want to double check.