1989 Luxfer cylinder VIP refusals

[marchand]

If a shop has 4000psi bottles it is cheaper for them to bank at 4000psi instead of 3500psi because they have to start up the compressor half as often. It is turning the compressor on that really eats up power.

 

[WD8CDH]

What size would that be??

35 CF with 1.250-12 UNF neck threads from a UDS-1.

 

[spectrum]

If a shop has 4000psi bottles it is cheaper for them to bank at 4000psi instead of 3500psi because they have to start up the compressor half as often. It is turning the compressor on that really eats up power.

Every compressor I have been around is up to speed in a matter of seconds. Sure there is a high draw for that period but it's only a time slice. Compressing gas to 4000 PSI to fill 3000 PSI cylinders takes a lot more energy than working to a maximum of 3500.

As long as the banks are of adequate size the extra start/stop events should not have a big impact on wear and tear either.

Pete

 

[spectrum]

If you're doing your own VIP, I'm surprised anybody fills your tanks. You might not like it, but the inspections are as much for their protection as yours.
Terry

I agree. As much as anything shops are starting to want to see an insured business behind the sticker. That puts the certified inspector / owner on thin ice. Its a combiination of revenue protection, the layers, insurance requirements and personal safety concerns.

Pete

 

[deepstops]

35 CF with 1.250-12 UNF neck threads from a UDS-1.

That's a fairly uncommon neck thread, your hydro facility is probably keeping that adaptor just for you (unless you are the hydro facility).

 

[oxyhacker]

Why the assumption that because he is doing his own visuals, that they are somehow suspect, or that he must therefore be opposed to the whole notion of annual inspections?

Most of the individuals I know who inspect their own tanks do it at least as scrupulously as the average shop. I think I have seen more bad visuals from dive shops than from individuals inspecting their own tanks. Most of us doing our own visuals know that they are necessary and desirable - and not for ours, or the diveshop's, exclusive protection, but for everybody's.

If you're doing your own VIP, I'm surprised anybody fills your tanks. You might not like it, but the inspections are as much for their protection as yours.

Terry

 

[savantblanc]

I first saw the "No Al prior to 90" rule on a Gulf-Diving live-a-board a few years ago. But they were using volunteer temporary tank fillers so I can see the simple rule in that case. Plus they provided replacement tanks for free for any effected divers so there was no question about motives.

Shops should have a much more stable environment and sufficient opportunity to screen and train employees that such simple but biased rules should be unnecessary. Perhaps the shop could add an additional sticker to record their verification that a pre-'90 tank is not the 6351 material and can be filled by that shop. It is just silly to be denying fills of older Catalina tanks unless the reading ability of the tank filler is in question.

I've been thinking about this for a while, and, although I disdain the arbitrary making of rules under the thin guise of benefitting the customer to belie an avarice; I don't think that such is the case here.

In reference to the blanket 1990 rule for aluminum, anyone who's seen "It's A Wonderful Life" knows how plausible it is that even a respected and well-educated professional can have "a bad day" Likewise, something so mundane as filling 30-40 tanks in an afternoon, everyday, can be difficult to maintain vigilance for. Mistakes happen.

At first blush, I like the idea of adding a sticker. In practice, however; waterproof stickers that are unique & customized are rather expensive. Minimum order requirements are compounded with set-up fees, and of course, there's no guarantee that the glue will hold-up to saltwater, or the friction of tankbands if used on the flat, or that the sticker won't peel itself off of a compound curve, like the shoulder.

Tank filling is bread & butter. For $4 each, there's not a whole lot of room for profit if you run a legal operation in a detached storefront. Obviously many small businesses are driven to skirt laborlaws, to remain solvent. In that regard also, why would they bother to invest in a roll of stickers if they want to maximize profit?

If a certification agency were to go through the trouble of printing up a run of stickers, then it could be fiscally feasable. But why would they? A move like that would not support the financial gain of the industry.

 

[Web Monkey]

Why the assumption that because he is doing his own visuals, that they are somehow suspect, or that he must therefore be opposed to the whole notion of annual inspections?

Yes, they are suspect.

Someone doing their own VIP is unlikely to have purchased a brand new eddy-current tester and even if they did, are more likely to "pass" a tank that has marginal defects where an unbiased inspection would fail it.

Terry

 

[WD8CDH]

That's a fairly uncommon neck thread, your hydro facility is probably keeping that adaptor just for you (unless you are the hydro facility).

It's not totally uncommon. It is used on some old fire extinguisher tanks. Probably a third of the hydro shops have the adapter. The big problem is making sure they DON'T use a 1" NPT adapter. It will fit with enough tape, but it might damage the threads.

 

[WD8CDH]

If a shop has 4000psi bottles it is cheaper for them to bank at 4000psi instead of 3500psi because they have to start up the compressor half as often. It is turning the compressor on that really eats up power.

It's not really the startup power. It's the startup wear that is the problem, so if you can reduce the number of startups, you will prolong the life of your compressor.