LP tanks

[jeffb78]

can someone tell me what the time limit is for getting LP tanks overfilled? will those shops that are willing to overfill generally stop doing it if a tank is past it's first hydro? weighing this in as a factor on HP vs LP tank purchase. i live in Jersey, and so far gather it's not easy to get LP tanks overfilled here at all (let alone after one or two hydros).

jeff

[aw]

Can I be real blunt here? The LP versus HP debate has been resolved by the new regulation stamped E8 series tanks. Most popular are the E8-130's which are essentially the old LP Steel 104's. The difference is the new E8 series is rated to 3460 psi. No more hassle with the local rec dive shop about overfilling crap. DON'T waste your time buying LP or HP. Go brand new E8 series. Save your money up until you can afford them. It will save you a lot of hassle.

[Gary]

can someone tell me what the time limit is for getting LP tanks overfilled?

If you are talking about the +10% overfill of steel tanks - they can continue to be overfilled the 10% (2400+240=2640) thru the orininal hydro. After that you have to get them hydro tested specifically for the 10% overfill. Supposedly it's just a matter of finding a hydro tester that can do the test (and passing the hydro within spec).

[DeWayne]

The + hydro can be redone indefefinitely; it is simply a matter of the test facility being set up to do the additional exansion test and the cylinder passing. Even if a + cycle has been skipped for whatever reason, if a facility tests and the cylinder passes it can be stamped with the + rating again. As for shops overfilling, most give no credence to cylinder age as long as the cylinder is in good condition. My favorite fill operator always answers the question, "How high can you fill it?" with the response, "How high do you want to take it to?" Overfilling will reduce the overall life cycle of the cylinder, by exactly how much is pretty much conjecture at this stage in the game.

LP cylinders offer the advantage of being able to get a full fill from fill stations not set up to pump beyond the 3000psig pressures common to recreational set ups. If your local fill stations can easily fill the higher pressure mid range cylinders, then they may be your best bet as you will have an easier time getting them filled to rated pressure than getting the LP's overfilled.

[jeffb78]

thanks for the advice!

[Puttzer]

I use Faber tanks. They are lighter than the Pressed Steel and easier for me to carry out of the water.

Are there any Faber type (weight) tanks that have the rated fill pressures of the new E series tanks?

Richard

[Jason B.]

Are there any Faber type (weight) tanks that have the rated fill pressures of the new E series tanks?

Richard

Faber does have the new FX series tanks which are rated at 3442 (like the E series from PST). Unfortunately, the weights (on land) are pretty much identical to the PST's though.

I have a set of doubled PST LP95's and a set of doubled Faber LP95's. I'm with you...out of the water, the Fabers (doubled up) are 13lbs lighter on land.

[lonestarfl]

I use Faber tanks. They are lighter than the Pressed Steel and easier for me to carry out of the water.

Are there any Faber type (weight) tanks that have the rated fill pressures of the new E series tanks?

Richard

Richard,
It is interesting to note that when Faber tanks were originally imported to the USA by Cressi-Sub over 15 years ago they had no DOT stamp and and a rated fill pressure of 200b or 3000psi without a 10% overfill. When Scubapro began importing the tanks they had a DOT stamp and were derated to 2640psi with the 10% overfill....same tank just derated to fit existing regulation and a change in color from yeloow to white. When OMS put their name on the Faber tanks the color changed from white to grey but not the fill ratings.
The Faber tanks are still sold in Europe today with a 200b rating and typically filled to 232b...a little over the 10% overfill.
So, the Faber tanks are engineered to withstand 3000ps1-3500psi fills as routine duty. It is only manufacturers jumping through goverment regulatory hoops that have them derated, not safety issues.
Kind of like the need for burst disc in valves...but that is a whole different can of worms!!!
Lee

[DeWayne]

I use Faber tanks. They are lighter than the Pressed Steel and easier for me to carry out of the water.

Are there any Faber type (weight) tanks that have the rated fill pressures of the new E series tanks?

Richard

Richard,
It is interesting to note that when Faber tanks were originally imported to the USA by Cressi-Sub over 15 years ago they had no DOT stamp and and a rated fill pressure of 200b or 3000psi without a 10% overfill. When Scubapro began importing the tanks they had a DOT stamp and were derated to 2640psi with the 10% overfill....same tank just derated to fit existing regulation and a change in color from yeloow to white. When OMS put their name on the Faber tanks the color changed from white to grey but not the fill ratings.
The Faber tanks are still sold in Europe today with a 200b rating and typically filled to 232b...a little over the 10% overfill.
So, the Faber tanks are engineered to withstand 3000ps1-3500psi fills as routine duty. It is only manufacturers jumping through goverment regulatory hoops that have them derated, not safety issues.
Kind of like the need for burst disc in valves...but that is a whole different can of worms!!!
Lee

I have heard so many different versions of this tale that it is hard to know what to believe these days. Seems like most folks say that the cylinders we have here and those in Europe are exactly the same, while others state that there is a difference between the two and thus the US cylinders are not capable of being repeatedly filled to the much higher pressures; different alloys and different specs such as wall thickness seem to be the most offered variances that I have heard. I have been filling my Fabers to typical "cave fill" pressures and have yet to notice any problems with them, but it would be nice to be able to read some "official" report to know which version of the marketing story is true. Do you know of such a source Lee?

[curtschu]

You own a fair sized manufacturing company. You make these steel things that people put gas in. I guy comes along and says will you make me 500 of these thing about this tall? Sure you say but hey can I sell them to other folks I hear thay like these in America too. Sure the guys says.... But I hear the DOT in America only lets you fill them 3/4 of the way so you will have to build two types.......... Um ok I'll do all that R&D to meet a lower standard than here in Italy....... Sorry it don't make fiscal sense they make one cylinder and stamp one for America and one for the smart people. Of course then they go and lose their minds over the types of gas and want everyone to use a different valve for each one
I tend to believe they make one cylinder and label accordingly