LDS - pulls the valve off my 02 tank??

[navyhmc]

On the 6351, I still have a tank that's circa 1982 and it's current on hydro, vip and eddy. I still get it filled the two places I dive the most so it's good enough for me. It gets vip'd about every 10 vs. 2 month just the be sure. I don't worry about filling it because I know it's history. I fill it just before the dive and at the most, when it sits, it's only had 500-800 psi in it for it's entire life-not much of a sustained load if you ask me. It's been well kept and not abused. I'm not worried about it with my tank-the LDS knows the tank history too and are good with it as well.

Yes, one of these days, I will say it's done-probably sooner than later because I have a new 80 to replace it.

I still wonder though...What was up with the hydro will take out the bow??? Has anyone heard of that before?

[Jack Hammer]

Originally Posted by navyhmc

...
I still wonder though...What was up with the hydro will take out the bow??? Has anyone heard of that before?

I imagine there's some confusion here. If I had to guess (no offense to the OP), I'd think the shop said something like we "need to have it hydroed to check out the bow." I recall seeing something (online) about tanks bowing out being a sign of them beginning to fail. There was something about an acceptable limit, not sure if that was visibly noticeable or not.

Just because it was filled a few weeks ago doesn't mean anything, the problem could have developed since then or just not been noticed. Either way I wouldn't want to be in the same building as a filled o2 bottle that is bowing out.

Jack

[navyhmc]

Actually, it's not uncommon for an AL tank to havea slight bow to them and it's perfectly ok to use it for a full service life. I don't have the tech specs in front of me but if the bend isn't too bad and the sides are paralell, it's okay. But I'm still confused.

[in_cavediver]

Read CGA 6.1 - it covers this.

A bow in a tank not designed to have a bow falls under the 'dent' classification. IE, a deformation where wall thickness is not changed.

CGA C6.1-1995
4.3 Dents. In general, dents which do not reduce the wall thickness can be tolerated. However, current practice is to accept dents up to 1/16th inch (0.062 inch; 1.575 mm) in depth when the major diameter of the dent is 2 inches (50.8 mm) or greater. See Figure 1.

[skdvr]

wasnt it the 86' tanks that luxfer said all were bad and was replacing, or was it later?

Phil

[skdvr]

To answer the OP's question about the bow, read the quote from a technical bulletin from Luxfers website

A bow is a slight curve in the sidewall of an aluminum cylinder. A fairly common cosmetic feature, a bow is not dangerous and does not affect cylinder performance. A bow is an occasional by-product of the manufacturing process, not a manufacturing defect. Bows occur most often in taller cylinders, including scuba cylinders with a capacity of 80 cubic feet or more.

A typical bowed cylinder has one convex side curving slightly outward and an opposite concave side (180° degrees away) curving slightly inward. The curves are long and gradual, covering much of the length of the cylinder sidewall. Most bows are barely discernible with the naked eye, but they sometimes become noticeable when you hold a straight edge against the cylinder wall and rotate the cylinder to reveal both the convex and concave sides. More severely bowed cylinders are sometimes called “banana shaped,” and even these cylinders are safe to use.

Infrequently a cylinder will have one straight side and one slightly convex (outward curving) side. Such a condition, called an unparallel sidewall or a plano-convexity, is also a type of bow. It does not affect cylinder performance.

Inspectors should be careful not to misidentify the harmless, slightly convex side of a bowed cylinder as a bulge, which is completely different and a very rare condition (see Figures 2 and 3).

Phil

[skdvr]

To correct my statement in post #15 it was 82' and 83' tanks that had the higher % of lead in them and that Luxfer was replacing under warranty. Just FYI that warranty is expired.

Phil

[navychop]

That is exactly what I told Scubaland Adventures in Austin, I even forwarded the link to the Luxfer inspection site and one from XSscuba. Since the last two inspections were from reputable LDS's, Toms Scuba and Oak Hill Scuba, they can't just pull a valve and drain a tanks without asking especially since it is current in Hydro and visual + and 02 cleaning. Scubaland did not offer an apology, just basically telling me to have it hydro'd again. Since when does Scubaland trump Federal inspection standard.

[JahJahwarrior]

Originally Posted by navychop

That is exactly what I told Scubaland Adventures in Austin, I even forwarded the link to the Luxfer inspection site and one from XSscuba. Since the last two inspections were from reputable LDS's, Toms Scuba and Oak Hill Scuba, they can't just pull a valve and drain a tanks without asking especially since it is current in Hydro and visual + and 02 cleaning. Scubaland did not offer an apology, just basically telling me to have it hydro'd again. Since when does Scubaland trump Federal inspection standard.

They can do whatever they please in the name of safety. In this case, you'd be hard pressed to argue that they were being ridiculous: they observed a visibly deformed tank made out of an alloy known to explosively self destruct, full of a gas which acts as an accelerant. In order to stay on the safe side, they immediately drained the tank. Once the tank was drained, they removed the valve to ensure that the tank was completely unpressurized and could not be repressurized.

At this point, they can refuse to fill the tank and you can do nothing to force them to fill it for you.

The only thing I do agree with you on is, they owe you the cost of the gas in the tanks. No more no less.

[jbres1]

Originally Posted by navychop

Took my 1986 Luxfer tank, last hydro in 05 with visual plus and 02 cleaning last month to a shop for a fill along with the other 86 vintage tank. The filled one, then didn't fill the other because it was "slightly bowed" and pulled the valve. I emailed the shop with the Luxfer 80 page plus inspection guide and a copy from XSscuba web site. Bowing is acceptable. Since when does a shop have a DOT hazmat authorized inspector? He claimed to have "failed" 4 tanks like this recently. Under what authority. Calling the shop, they tell me I should get the tank hydro'd again, they heard that may straighten out the bow.

If it is within DOT specs, passed a visual plus, what right does a shop have to tell me it can't be filled. So do I know have to spend 40 for a hydro and 75 for an 02 cleaning, when ST has new tanks for a little bit more??

I think the better business bureau, PAD and DOT should get a complaint. What do you think?

Hi,

I think you are just venting here, but here is my take on it.

1) a shop can do what ever it wants to with respect to filling or not filling your tank. They are the ones that take the chance of it going boom durring the filling process.

2) alot of shops here in Chicago will not even fill an old Luxfer cylinder.

3) how much of a bow was it? Was the bow within the limits per the cylinder inspection , and what standards does this shop go by. ( PSI or TDI )

4) show your feelings for the shop by never spending another cent there.

As for the tank no longer being o2 clean, just removing the valve doesn't make it dirty.


Jim