Filling LP tanks to high pressure

[captain]

OK how can I take anything that site says seriously when in the very first paragraph it says that cylinders are only in service for fifteen years?

(BTW my cylinders stay current with hydros - and how come I can keep getting hydro's on cylinders that are 30 or more years old? and OBTW... one could bet the farm they have seen some cave fills, living in caving country for three decades ):

Never play with an out of hydro or non-certified cylinder. Using an out of hydro or non-certified cylinder is not only dangerous to yourself and others but it is also a federal DOT violation to use, fill, and transport. The DOT hydro testing laws are not a suggestion, they are a requirement for the safety of you and the others around you. The hydro test can be done locally at a dive shop, paintball field, or sent to various paintball vendors that offer the service through their websites or stores. The hydro test ensures the proper expansion and contraction of your tank. You can not test it any other way then with the hydro test. It's inexpensive overall and only comes every 3 to 5 years depending on your cylinders permit number. A tank is only in service for 15 years in total so if you have a 5 year cylinder you only need to do the test twice before the tank must be taken out of service. Using an out of hydro cylinder at a field or national tournament can lead to you be removed from the premises or disqualified from play. This is a very serious matter, it is not a joke, it is not something to skirt and argue. Fields can face fines for filling an out of hydro tank and denying your two dollar fill is a much better option then facing those consequences. The same goes for a non-certified cylinder, it does not have the DOT clearance or testing to ensure it meets their safety standards and is there for not acceptable to use, fill, and transport.

If it is referring to hoop wraped composite cylinders the site is correct.

Luxfer Carbon Composite Cylinders Inspection Manual 2009 - Luxfer: Setting The Standard Worldwide

 

[lv2dive]

OK... so what in the Sam Hill does that thread/post have to do with do Scuba Tanks? Steel or Aluminum, for that matter?

If it is referring to hoop wraped composite cylinders the site is correct.

Luxfer Carbon Composite Cylinders Inspection Manual 2009 - Luxfer: Setting The Standard Worldwide

 

[Bob DBF]

OK... so what in the Sam Hill does that thread/post have to do with do Scuba Tanks? Steel or Aluminum, for that matter?

There are other SCUBA tanks.

http://www.diveseekers.com/Luxfer_Limited_106_CF_Composite_Cylinder_LALW106_p/lalw106.htm

L6X® Hoop-wrap cylinder specifications - Luxfer: Setting The Standard Worldwide



Bob
--------------------------------
"If you don't like it, go on the internet and complain." Brian Griffin

 

[lv2dive]

Someone linked to a website that had a "safety" discussion related to "tanks" blowing all to heck - implying that it was relevant to the discussion that we were having, regarding Aluminum and steel tanks.

I called the website out bc in the first paragraph it said something about a 15 year lifespan of tanks, bc I assumed we still on the original topic, ya know, steel and aluminum tanks and likelihood of blowing up due to overfills.

Well bad on me...someone responded and noted, that link was referencing composite tanks. Obviously I was confused, bc I assumed the link would be going to topic that had something to do with the discussion at hand?

So trying to stay on topic here, I asked, really what does that have to do with SCUBA tanks?

And I get a response that some people use composite tanks for SCUBA? RLY???? OK the exception proves the rule I guess.

The one review on one of the websites which was linked, even said they they did NOT purchase it to use for scuba !!! OK, so yes composite tanks CAN BE used for SCUBA. But... I would argue that 99+% of the tanks that are used for SCUBA are aluminum or steel? And this is a silly side conversation about composite tanks that is completely irrelevant.

There are other SCUBA tanks.

Luxfer Limited 106 CF Composite Cylinder w/ DIN valve *Buy Luxfer at DIVESEEKERS.com 888-SCUBA-47

L6X® Hoop-wrap cylinder specifications - Luxfer: Setting The Standard Worldwide



Bob
--------------------------------
"If you don't like it, go on the internet and complain." Brian Griffin

 

[Eric Sedletzky]

All I want to know after reading all this is can I routinely fill my in-hydro and rust/pit-free steel 72's to 3000 to get 80 (and some change) CF, yes or no?

 

[halocline]

All I want to know after reading all this is can I routinely fill my in-hydro and rust/pit-free steel 72's to 3000 to get 80 (and some change) CF, yes or no?

It's a matter of how comfortable you are. Personally I try to get mine filled to 2700 where they have 77cft or the equivalent of an AL80. You only need to go to 2800 to get them to 80. I rarely get that much air in them, though, and I don't lose any sleep over it.

If tanks very rarely but occasionally do rupture during hydrotest, that is an indication, to me anyhow, that there is some increased risk of catastrophe in filling them to near test pressure. One presumes that tanks undergoing hydrotest have already passed a visual before they go in the hydrotank. Anyhow, since test pressure for the LP72s is 3750, my personal comfort level would be roughly around 1000 PSI under. That's a completely arbitrary figure and since I'm rarely in a position to dictate how much air I get at a fill, it usually doesn't matter.

 

[AfterDark]

It's a matter of how comfortable you are. Personally I try to get mine filled to 2700 where they have 77cft or the equivalent of an AL80. You only need to go to 2800 to get them to 80. I rarely get that much air in them, though, and I don't lose any sleep over it.

If tanks very rarely but occasionally do rupture during hydrotest, that is an indication, to me anyhow, that there is some increased risk of catastrophe in filling them to near test pressure. One presumes that tanks undergoing hydrotest have already passed a visual before they go in the hydrotank. Anyhow, since test pressure for the LP72s is 3750, my personal comfort level would be roughly around 1000 PSI under. That's a completely arbitrary figure and since I'm rarely in a position to dictate how much air I get at a fill, it usually doesn't matter.

I'd second the above. My own 72lps have gone to 3000 psi; found a weak burst disk in one valve and a little extra time from the other tank. They regularly go to 2500psi and I complain if they don't; 2800psi wouldn't faze me a bit, but I don't get to vote on that.

 

[pocky21]

Someone linked to a website that had a "safety" discussion related to "tanks" blowing all to heck - implying that it was relevant to the discussion that we were having, regarding Aluminum and steel tanks.

The intent was to show that tank ruptures can happen, do happen, and can really mess your day up when it does happen. While the materials, application, and chain of failure are different, we are still dealing with a pressurized vessel that contains a very large amount of stored energy. Such things deserve, at the very minimum, a bit of respect.

If you would like reading about scuba tanks specifically, I found this website to be a valuable resource as well.

 

[Jared0425]

If you would like reading about scuba tanks specifically, I found this website to be a valuable resource as well.

That website shows old and deficient tanks, not anything that I would ever dive with nor will ever get to that point.

 

[AfterDark]

That website shows old and deficient tanks, not anything that I would ever dive with nor will ever get to that point.

If some nit-wit hits your car while you have one of your highly maintained, clean, rust free, vip'd and hydro'd tanks in it and breaks the valve you'll come to realize why displaying the power you are carrying is relevant. If that requires old and deficient tanks, so be it. Just don't think you are immune because your tanks are good. Sh!t happens.