Tank Help

[Divemstr13]

Alum. cylinders manufactured from 1972 - 1988 made with the 6351 alloy where the cylinders that where susceptable sustained-load cracks.

Since then a new alloy has been used ( 6061 ) and no sustained-load cracks have been reported since as per. the Luxfer seminar at DEMA.

Also Eddy Current Testing ( VIP PLus ) is not only NOT required on the 6061 alloy cylinders but using Eddy Current on the new alloy can result in misleading fasle positive readings.

To keep the crack issue in perspective, the cracks where from a long period of sustained load. Over fills and high volume use such as rentals are also contributing factors.

 

[Rick Murchison]

I don't know why this misconception comes up over and over - I suppose it's been repeated so much it's "common knowledge." But the fact is that LP steels are *not* necessarily larger, or heavier than a comparable aluminum tank.
For example, a Faber 80 (LP steel), which holds 78CF at 2640 psi, weighs 30 pounds empty, is 7.25" in diameter and is 24" long without the valve. A Luxfer 80 (your standard AL 80) holds 77.4 CF at 3000 psi and weighs 31.4 pounds empty, is 7.25" in diameter and is 24" long without the valve.
In the 100 CF range, the AL 100 from Luxfer holds 99.3 CF at 3000 psi, weighs 40.9 pounds empty, is 8 inches in diameter and is 27.3" long without the valve, while the OMS 112, for example (LP steel), holds 112 CF at 2640 psi, is 8" in diameter and 26" long without the valve.
So in both these cases the steel tanks hold more, are lower pressure, lighter, and the same size or smaller than their aluminum brethren.
There are indeed some steel tanks that are heavier and bigger, but it ain't necessarily so.
Rick

 

[Divemstr13]

Except for one little itsy bitsy, teeney weeinie detail; Luxfer alum. 100 is 100 cu ft @ 3300 psi.

 

[large_diver]

Rick -- you are correct......there are exceptions...it depends on what size you are talking about. I think I should have been more clear about this in my original post above.

 

[blacknet]

Hello,

That's great info to give out - Never Overfill. Overfilling is a VERY good method to get someone injured or killed.

Ed

 

[Rick Murchison]

It is unwise to overpressurize tanks. Indeed, when OMS relables Fabers as their own they even stamp "DO NOT OVERPRESSURIZE" right on the shoulder because this dangerous practice is so widespread.
If you need 98 CF buy a 98 CF tank.
Rick

 

[blacknet]

Hello,

Please inform us which company makes the OMS tanks? Also tell me the company who makes faber tanks . As for as burst disk not being used outside the US. We are NOT talking about outside the US and we don't care what they are doing outside the US with burst disc. This is IN the US and we have rules and regulation, they are put in place for safety concerns, if you wish to go outside the US and violate these safety protocols then by all means go for it, just don't expect any support or sympathy from this crowd.

Ed

 

[Rick Murchison]

No need to censor so long as we're all clear that you are offering BAD ADVICE.
If you're lucky all overpressurizing tanks will do is result in an early rejection at hydro. The widespread use of overpressurization is a fairly recent phenomenon, and shortened tank life or catastrophic failure hasn't to my knowledge happened yet. But just like overspeeding tires, you can usually get away with it - but sooner or later somebody's gonna get killed.
Lest anyone have any doubts, OVERFILLING TANKS IS NOT SMART!
Rick
PS - OMS tanks are Faber tanks

 

[joewr]

just out of curiousity, what were the pressure ratings on those wine jugs you used to get at the Rubiyat Liquor Store?

Joewr...wondering if you can overpressure a loaf of bread?

 

[joewr]

As I remember, and correct me if I am wrong, one of the great pieces of literature in this world is the Rubiyat by Omar Khayyam.

"A loaf of bread, a jug of wine and thou. Paradise enow."

Seems to me that it would be an honor to be in the same sentence with Omar the Tent Maker. Even if in a humorous mode... So, tell me how it is a racial slur... And I am serious here! I love the Rubiyat and am somewhat taken aback that you would come to a different conclusion...

If your name were Ishmail and I started a post with "Call me Ishmail," would you consider that a slur against New Englanders and Herman Melville?

I am more than curious...

Joewr...