pony bottle question

[TMHeimer]

[QUOTE KWS:

I think that the most prudent course to take is the conservative one and comply with the hydro requirements and the vis requirements which are by the way not an anual thing. If i remember the vis requirement is anual for tanks that are filled up to twice a week for the years period and those that are filled more often require more frequent vis schedule. So its more like vis every 100 fills. Even that is subject to whether it is a rule or recommendation.


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What you say probably makes good sense. But I've never heard of a visual being based on 100 fills, or for that matter, anything other than once a year. Logic says if you only dive 2 times in a year you probably don't need a visual, but the LDS doesn't know how many times you dive, thus the 1 year rule, I suppose. Anytime I need a fill, particularly from a shop other than my own LDS, they immediately look for the visual & hydro dates. Some U.S. shops are puzzled with my Canadian hydro markings. Anyone else hear of 100 fills, etc.?

 

[-hh]

A full scuba tank is an unexploded bomb. They can and do kill. Saying it is about lawyers and a cash cow discards the fact that there are serious idiots out there that put others at risk. The reason it seems excessive is because it is effective and we seldom hear about accidents that don't happen. If they blew up all the time we would be hang a different conversation.

Understood, but I'm afraid that you're missing the point. To start to illustrate, go down to your LDS and ask them how frequently they VIP their rental tanks - - I'll bet you a beer that your LDS isn't faithfully doing 4x/year.

From an engineering perspective, the current system is reasonably well over-engineered such that 300 fill cycles (for a 1x/year inspection interval) is usually more than satisfactory, assuming no gross operator goof-ups. The hydro fill requirements actually do more metallurgical damage.

However, diving is always a business and the downside cost risk from litigation from any bad event creates a motivation for contrived exclusionary requirements: for example, if tank manufacturers could get away with it, they would simply exclude all 'commercial use' of their product, since rentals are where most of the risk exposure comes from because it is where most of the fills are done...however, it is also where most of the tanks are sold.


-hh


PS: I 'made up' the 100 fills just to be an example. From an engineering perspective, the fill/empty of a tank is simply cyclic loading which in simple form is just a fatigue cycle limit calculation: ignoring obvious exceptions, time is not a contributing variable..yet the dive industry chooses to use time (eg, Annual VIPs).

 

[FoxHound]

What you say probably makes good sense. But I've never heard of a visual being based on 100 fills, or for that matter, anything other than once a year. Logic says if you only dive 2 times in a year you probably don't need a visual, but the LDS doesn't know how many times you dive, thus the 1 year rule, I suppose. Anytime I need a fill, particularly from a shop other than my own LDS, they immediately look for the visual & hydro dates. Some U.S. shops are puzzled with my Canadian hydro markings. Anyone else hear of 100 fills, etc.?

Nope the 100 fill thing doesn't exist at least for Alu tanks.

the post I have up on the previous page about heavy use tanks is verbatim from luxfer and Cat manuals, luxfer is 4 months VIP if heavy use, cat is 6 months...both have different regs as what constitutes heavy use.


the inspection manuals for both are available online for anyone.....i'd go download a copy, never hurts to have more info.

 

[Peter69_56]

Come down under to Aus. Hydro and vis yearly.

 

[CT-Rich]

Come down under to Aus. Hydro and vis yearly.

1) if I lived in Australia, I would likely make 300+ dives a year.
2) I would likely put up with almost any pain in the ass restriction to make those 300 dives....

 

[TMHeimer]

Come down under to Aus. Hydro and vis yearly.

Just out of curiousity, do you know if there are statistics that prove that yearly hydros are better? There are a lot of divers in N.A. not doing this. Kind of like yearly car inspections on the East Coast vs. none out West. Statistics? If it works, why not out West too?

 

[Peter69_56]

We have had few Cylinder failures reported and most I think was to do with material issues on earlier cylinders than anything else I have had one cylinder scrapped due to its material and refusal to have it filled (manufactured before nov 1991) rather than a fault and another that just failed hydro

---------- Post added March 18th, 2013 at 02:48 PM ----------

I don't mind paying if a good reason and proven safety but hate it when it's an idea for money leaches to increase profits only