Tank hydro question

[XS Scuba]

Hi Rachel:
The Luxfer Limited has been available for about 3 years, so it's new, but not way new. You're correct that the ability to fill the cylinder full to 4350 psi is a factor that has limited the sales and popularity of this cylinder. Other limitations are the 3 year hydro / 15 year life, the only compatible valve is a dedicated 300 bar outlet, smaller 7/8 x 14 UNF inlet thread, relative high cost and the ability of the divers regulator / pressure gauge to handle the 4350 psi input. The ALW106 is basically a standard Luxfer 80 with the addition of the hoop wrapped fiberglass and resin, so the in water buoyancy is essentially unchanged. On the positive side is, if filled full, it's a bunch of gas in a small package. The majority of the sales of this cylinder have been for uses other then scuba.

I'm totally intrigued by this new Luxfer tank...

The biggest issue I see is actually getting it filled to rated pressure since most fill stations don't even bank enough pressure to properly top these off.

Do you have any experience with these tanks and what is your general impression?

Rachel

 

[erdoc1]

Hydrostatic testing is a very specific measurement of tank expansion. There is no "opinion" about it. Either a tank passes, or it fails.

There is a visual that's performed prior to hydro that is more likely (in my experience) to fail a tank than the actual hydro itself and tank age is often a factor there, but not because of the age of the tank, per se, but because the alloy that older tanks were made from are more likely to develop neck cracks.

Is that too much information?

Rachel

Rachel - clear out your inbox so I can PM you!!! We have to set something up for dives in March... I am so excited.

 

[Packhorse]

How often do tanks need hydros and visuals in your part of the world?
In New Zealand tanks must be hydroed every 2 years and visuals must bee done every year inbetween.

 

[XS Scuba]

Hey Packhorse:
In the US, the DOT requires nearly all scuba cylinders to be retested by hydro every five years. Visual inspections are done annually.

How often do tanks need hydros and visuals in your part of the world?
In New Zealand tanks must be hydroed every 2 years and visuals must bee done every year inbetween.

 

[Al Mialkovsky]

Not yet.
Rick

Rick do you think eventually they will fail due to dates?

 

[cnctina]

Years ago I had two old steel 72's that a dive shop would not fill because there was rust on the outside so I repainted them and then the dive shop filled them. So even if the cylinders have current hydro's it's up to the dive shop if they fill them or not.

 

[DA Aquamaster]

I would not fill a tank with rust on it either. Removing rust from the outside of a tank is fairly serious business. A rust coverter or other chemical treatment to neutralize the rust is a good idea to prevent any further rusting or pitting under the paint. You definitely do not want to cheat either and hide any pitting under a coat of paint.

For that reason many shops may require a new hydro test on a newly painted tank before they will fill it. On aluminum tanks it's even more of an issue as some paint processes invlove curing the paint at temperatures that can reduce the hardness of heat treated aluminum alloy with explosive results on the first fill.

I am not a big fan of hoop wrapped tanks for diving. If you gouge through the resin and expose the wrap underneath you have a serious problem that is made far worse by expsure to water. At a minimum the tank will need to go back to luxfer for inspection and repair (if it's even possible).

So in my opinion the Luxfer limited is an expensive tank that is fragile, life limited and offers no advantage over a 3442 psi steel PST E7-100 that would have better bouyancy traits, be far more durable, be easier to get fully filled and have the potential for lasting a lot longer than 15 years.

 

[wreckchick]

ERDoc,

I got your PM and replied! If it didn't go through, I'm so sorry!

Give me a call (305) 515-2750.

Rachel

 

[najord]

what is the LDS ?

 

[donnyb]

what is the LDS ?

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