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View Full Version : Used Steel Tank Pressure Rating.. How can I tell



swamibob
01-31-2010, 11:02
I am writing to see if someone can educate me on how to read the cryptic codes on the side of a scuba tank. I have a friend who will sell me his used tank for $65 but I want to make sure it is a high pressure 3400-3500psi steel tank. I have attached the pic he sent me. I'm not sure if these are the numbers we need to figure it out or if this is just the hydro stamp. I was thinking the numbers we need include DOT in the set. The tank need a hydro now and an inspction. Do you think it is worth $65?

Thanks,
Swami

ScubaToys Larry
01-31-2010, 11:28
You are right... that's just hydro stuff...

And interesting to see Italy there... might be a european tank without a DOT stamp on it, which would mean it's not much good here...

But have him shoot the part that says something like:

DOT / CTC 3AA 3442

or something like that... that would be a steel tank 3442 psi...

Panmanmatt
01-31-2010, 11:36
Larry, can HP tanks get a "+" rating too? I was under the impression that the "+" rating was only for LP tanks.

Beefcake
01-31-2010, 12:57
What size tank is it? If it is a reasonable size (80cf or bigger), $65 seems like a steal unless it is obvously damaged or rusted inside. Also, there is nothing wrong with modern low-pressure tanks (which this probably is based on the "+" rating). As an example, LP95 tanks are very popular in the NW. They usually sell used here for between $150-250 depending on condition and last hydro date. The main downside to a tank like an LP95 is that they only hold 95cf if they get the plus rating on the hydro, which many hydro shops are unwilling or don't remember to do even if the tank is within specs, so legal fills after the original hydro are often only to 2200 lbs (about 86cf?). This really isn't a big deal, but its something to think about.

If that tank is a 95cf or bigger and in reasonable shape, I'd buy it for that if you don't take it...

Jack Hammer
01-31-2010, 14:18
You definately need more information on it before seeing if it's a great deal or not. That includes the rest of what's stamped on the neck and the interior condition of it. Just because the outside is clean does not necessarily mean the inside is too.

comet24
01-31-2010, 14:28
Larry, can HP tanks get a "+" rating too? I was under the impression that the "+" rating was only for LP tanks.

Your correct. HP tanks can not get a "+" rating.

Panmanmatt
01-31-2010, 14:41
Larry, can HP tanks get a "+" rating too? I was under the impression that the "+" rating was only for LP tanks.

Your correct. HP tanks can not get a "+" rating.


Thanks for the clarification. I figured the tank in question was LP, but wanted to make sure.

ScaredSilly
01-31-2010, 18:14
And interesting to see Italy there...

Not if the cylinder was made by Faber. Mine have either "Faber Made in Italy" or "Faber Italy" stamp on them. In fact, if you look hard enough you can make out "Faber" to the left of Italy. The R is pretty clear.

Further, the original hydro mark is that of Faber. In addition, the secondary hydro mark is that of a US hyrdo facility (D117 - no longer an authorized tester, but that is moot).

So, at this point you have a cylinder that was made by Faber. It is either LP (2400) or MP (3000 or 3180) that can be over filled by 10% if given the plus rating at the time of requal. Finally, to answer your original question it is certainly not, a modern HP cylinder. Note the MP 3180 are nice single cylinders as they are quite negative buoyancy wise. My guess, is that the cylinder is a LP80 / LP85. And yes Faber used to make cylinders with a galvanized coating.

ScaredSilly
01-31-2010, 18:35
The main downside to a tank like an LP95 is that they only hold 95cf if they get the plus rating on the hydro, which many hydro shops are unwilling or don't remember to do even if the tank is within specs, so legal fills after the original hydro are often only to 2200 lbs (about 86cf?).


You almost got it right. The working pressure is 2400 psi. At that pressure the cylinder would hold ~86 cuft. If the plus rating is valid then the working pressure is 2640 psi and the cylinder would hold 95 cuft.

swamibob
01-31-2010, 19:27
He wrote me back and told me this

" I had it filled when diving at 3200 but never 3400 but that is the dive shop I used policy"

He is going to try and get more information for me. I am going to ask if he can get a shot of the other markings on the tank and i will repost those pics as well.

thanks all,
swami

Panmanmatt
01-31-2010, 19:38
It's an LP tank so 3200 would be what is commonly called a cave fill. It's technically not a legal fill for an LP tank as it exceeds DOT standards for that tank.

If you are filing your own tanks then you can fill it to just about anything you want to, it's your life at risk if it explodes from the pressure. Most dive shops will only fill tanks to their intended pressures as that is all they are legally allowed to do.

ScaredSilly
01-31-2010, 20:10
It's an LP tank so 3200 would be what is commonly called a cave fill. It's technically not a legal fill for an LP tank as it exceeds DOT standards for that tank.

Not necessarily, as I posted Faber made LP and MP cylinders that have a plus rating. If he got it filled BITD at 3200 psi it could well be a MP cylinder which has a work pressure of 3180psi. Though with a plus rating a legal fill would be 3498 psi.

Panmanmatt
01-31-2010, 20:19
Well then I guess we'll have to wait for the rest of the info to be sure.

ScaredSilly
01-31-2010, 21:04
That said I would agree and guess that it is a LP80

Here is it's cousin ... note all of the markings.

1--Faber Scubapro Steel Scuba Tanks W/Valve NR - eBay (item 150410000238 end time Feb-07-10 18:00:23 PST) (http://cgi.ebay.com/1-Faber-Scubapro-Steel-Scuba-Tanks-W-Valve-NR_W0QQitemZ150410000238QQcmdZViewItemQQptZLH_Defa ultDomain_0?hash=item230522776e#ht_855wt_1167)



Faber LP-80 2400psi +10% 78cuft 7.25" dia 24" tall 30 lbs buoyancy -1.7 empty -7.55 full.

Great singles, a bit too negative as doubles for me

UCFKnightDiver
02-01-2010, 06:41
It's an LP tank so 3200 would be what is commonly called a cave fill. It's technically not a legal fill for an LP tank as it exceeds DOT standards for that tank.

If you are filing your own tanks then you can fill it to just about anything you want to, it's your life at risk if it explodes from the pressure. Most dive shops will only fill tanks to their intended pressures as that is all they are legally allowed to do.

A 3600 fill is more commonly thought of as a cave fill on a LP Steel tank, and at that pressure lp wont explode, its tried and true.

CompuDude
02-01-2010, 15:18
This may help, as well:

http://i70.photobucket.com/albums/i114/mikes2006/tanks/tank_read_steel_tank.gif

awap
02-01-2010, 17:28
Fabers used to make a 72 that was rated 3000psi + 10% giving it 3300 psi. They also made an 80, 100, and 120 that were rated at 3180psi +10% giving them about 3500 psi.

jeffgerritsen
02-02-2010, 15:12
I purchased two fabers on craigs list and did the research on faber information. Here is some information from the faber website (Scubadiving cylinders Faber leader in scuba diving cylinders Faber steel cylinders, diving, scuba, diving cylinders, diving cylinders, diving cylinders, scuba diving cylinders, sub SCUBA scuba DIVING (http://www.divefaber.com)):


Standards and regulations of all countries require the name of the manufacturer, or its code, or its symbol, to be stamped on the dome of the cylinders. All the cylinders produced by Faber Industrie Spa for scuba diving are stamped FABER.

Only in US some of them are stamped M8303 which is the DOT code for Faber...

Also here is the tank specs on fabers:
Faber Industrie (http://www.divefaber.com/list/print/scuba_lpr_a.asp?da=610&a=9999)


If the tanks are plus rated and have an "REE" number stamped on the tank neck, when hydro'ed, if the tank still meets the "REE" value, you maintain the plus rating and get the overfill pressure. A reputable hydro shop will explain what all this means. If you don't have the plus rating, the dive shop can only fill to the "stamped" pressure.

The prior owner of the faber tanks I purchased took them to a less than reputable hydro shop and they forgot to stamp the plus marking next the hydro date. I took them back to the hydro shop I use and had them retested (after two years from the last hydro) and got the "offical" plus rating back - they passed the REE value.

I hope this helps.

Jeff

jeffgerritsen
02-02-2010, 15:21
I am writing to see if someone can educate me on how to read the cryptic codes on the side of a scuba tank. I have a friend who will sell me his used tank for $65 but I want to make sure it is a high pressure 3400-3500psi steel tank. I have attached the pic he sent me. I'm not sure if these are the numbers we need to figure it out or if this is just the hydro stamp. I was thinking the numbers we need include DOT in the set. The tank need a hydro now and an inspction. Do you think it is worth $65?

Thanks,
Swami

The picture only included the last hydro stamp and below I saw an 04 88 + date - most likely the original manufacture date of April 1988 with a plus rating.

The hydro stamp code breaks down as:
10 01 = Oct 2001
D117 (read clockwise) is the testing facility code issued by DOT
+ = the tank still maintains the plus rating, IE it passed the REE value.

I know, TMI (too much information...)

Jeff.