It says right on my tanks - DO NOT OVERPRESSURIZE

[Ted Judah]

A year ago, I bought tanks for my wife and I. In that year we have used them on 16 dives and had them filled at 5 different dive shops. The pressures after each fill seem to vary wildly and is often overfilled.

Here are the markings on the tanks:

FABER MADE IN ITALY M8303 21/0154/ 073 02•21+
TC - 3AAM - 184/DOT - 3AA2400 DO NOT OVERPRESSURIZE REE67 BS85S


Below are the start fill pressures for each dive:

2400 lbs.
3400 lbs.
2600 lbs.
2500 lbs.
2500 lbs.
2500 lbs.
2200 lbs.
2800 lbs.
2800 lbs.
2800 lbs.
2950 lbs.
2400 lbs.
3000 lbs.
2750 lbs.
3250 lbs.
3525 lbs.

Am I missing something? should I be concerned? Should I request a certain pressure from dive shops?

 

[Marie13]

I can only get 3400 in my LP 85s.

A few shops will only fill to 3000-3100 in my LP85s. But that’s better than service pressure.

 

[Eric Sedletzky]

A year ago, I bought tanks for my wife and I. In that year we have used them on 16 dives and had them filled at 5 different dive shops. The pressures after each fill seem to vary wildly and is often overfilled.

Here are the markings on the tanks:

FABER MADE IN ITALY M8303 21/0154/ 073 02•21+
TC - 3AAM - 184/DOT - 3AA2400 DO NOT OVERPRESSURIZE REE67 BS85S


Below are the start fill pressures for each dive:

2400 lbs.
3400 lbs.
2600 lbs.
2500 lbs.
2500 lbs.
2500 lbs.
2200 lbs.
2800 lbs.
2800 lbs.
2800 lbs.
2950 lbs.
2400 lbs.
3000 lbs.
2750 lbs.
3250 lbs.
3525 lbs.

Am I missing something? should I be concerned? Should I request a certain pressure from dive shops?

In the first five years those can be filled to 2640 because you have a + stamp after the born on date. The advertised cubic foot size is with a 10% overfill, not the stamped 2400.
The “do not overpressurize” pertains to the ree and the max hydro pressure.

 

[JohnN]

In the first five years those can be filled to 2640 because you have a + stamp after the born on date. The advertised cubic foot size is with a 10% overfill, not the stamped 2400.
The “do not overpressurize” pertains to the ree and the max hydro pressure.

A guy I often dive with has some LP72's that date to the mid '90s, they still have a "+" rating

 

[DeepSeaExplorer]

I'm not suggesting changing valves but this is one of many feature on the XS Scuba valves that are worth considering if you buy replacements:

View attachment 742469​

Thanks, that’s good info - on what valves not to buy.

 

[wnissen]

A year ago, I bought tanks for my wife and I. In that year we have used them on 16 dives and had them filled at 5 different dive shops. The pressures after each fill seem to vary wildly and is often overfilled.

Here are the markings on the tanks:

FABER MADE IN ITALY M8303 21/0154/ 073 02•21+
TC - 3AAM - 184/DOT - 3AA2400 DO NOT OVERPRESSURIZE REE67 BS85S


Below are the start fill pressures for each dive:

2400 lbs.
3400 lbs.
2600 lbs.
2500 lbs.
2500 lbs.
2500 lbs.
2200 lbs.
2800 lbs.
2800 lbs.
2800 lbs.
2950 lbs.
2400 lbs.
3000 lbs.
2750 lbs.
3250 lbs.
3525 lbs.

Am I missing something? should I be concerned? Should I request a certain pressure from dive shops?

If it makes any difference to you, I work with people whose whole job is the failure and fracture of metals. They assure me that there is effectively no danger in filling a steel tank to a pressure that the tank has seen before. Steel is quite flexible and the grain structure stretches like a rubber band. It won't break unless you take it past the breaking point. I don't blame any shop or person for not wanting to take on the risk of an overfill, but it's exceeding unlikely, closer to a lightning strike type of event.

Once the tank has been filled, it starts to cool and shrink, relieving the stress. As long as you keep the tank cool it will be fine. I'm not sure there has ever been an instance of a tank exploding on a user's back. The risk is borne by the fill station, not you.

 

[Minion_Diver]

If my LP tanks come back to me at 2400 or 2600 I do not consider them "full" even though they are at their rated pressure. My local shop normally fills to between 3600 to 3800, they would fill higher but boosting O2 that high can lead to some explosive habits and we don't want that.

 

[crofrog]

they would fill higher but boosting O2 that high can lead to some explosive habits and we don't want that.

why would they add O2 at the end?

 

[Minion_Diver]

why would they add O2 at the end?

Filling rebreather O2 bottle.

 

[Subcooled]

Could someone please explain to me why the tank manufacturer says 2400 and gas blenders say 2800 or even 3400?
Repeated overfilling does cause metal fatigue, doesn't it?
Steel, as far as I know, is more tolerant than aluminum, though.

Perhaps Faber could give us a definitive answer? They surely know something about the issue at hand.

 

[Superlyte27]

Could someone please explain to me why the tank manufacturer says 2400 and gas blenders say 2800 or even 3400?
Repeated overfilling does cause metal fatigue, doesn't it?
Steel, as far as I know, is more tolerant than aluminum, though.

Perhaps Faber could give us a definitive answer? They surely know something about the issue at hand.

Here we go again. This topic is covered several times per year. Search it.