Tanks and Weights

Well – maybe it shouldn’t have taken me by surprise.  But it did.  A communicating New England area dive shop told me, “It’s OK to sell integrated weights BCs because divers don’t drop their weight-belts anyway.”  An honest peddler – at least honest in describing his outlook.  Almost as bad as, “I have insurance for that.”

Under the banner of, “It’s our livelihood,” we have dangerous junk being sold because “…they don’t drop their weight-belts anyway…” (that really floored me), “Sell the aluminums ’cause we can “crack fail” them in a couple of years.”  “It’s a ‘low-flow’ regulator – they put them on pony bottles.”  Someone tried that one on me.  Imagine?  Putting what he classed as a “low flow” regulator on a “pony bottle” justified its existence in some way or other.  I couldn’t make the connection – but – if the effen thing was for making an escape to the surface, why put all your marbles into a “low flow” regulator?

The last people who should be passing their hands over scuba cylinders are people who sell them.  In this economy, the lure is too great.  The DOT almost prohibits such a close association.  TITLE 49 CFR 2010 (107.803):: “…No independent inspection agency…may have a financial involvement with any entity that manufactures cylinders …except as an independent inspector (such as myself ).

Fred Calhoun doesn’t sell cylinders, he is “qualified” to inspect, and he inspects.  His customers often visit dive shops for air fills, and are subject to a litany of questions implying that maybe there’s something wrong with the cylinder, or the person who did the inspection and affixed the EOI sticker.  I’m qualified (I don’t sell the things).  I have a wallet c-card that has my name on it – says I’m qualified.  I wrote the book SCUBA CYLINDERS AND TITLE 49, CODE OF FEDERAL REGULATIONS.  If anyone is qualified, you’re readin’ his writin’.  Shops that regularly “fail” cylinders (you wouldn’t believe the stories that come across the gunwale), by-and-large don’t do it right.

I’m a licensed construction supervisor.  I’ve regularly dodged compressed gas cylinders at construction sites at a regular rate.  They get driven over, knocked over, you name it.  Do you know how long steel cylinders last?  Practically indefinitely.  The earliest retest date I’ve seen on K tanks was 1927 (older than I am).  At dive sites, scuba cylinders do not suffer the same manhandling that I’m talking about.    But, if in one’s haste a 2250 steel is banged to 5000 (aluminum 50s and 80s test pressure), it won’t last long, if at all.  Inexperienced people in dive shop fill stations, who are not paying attention, could fail several steel seventies without batting an eyelash.

We became PSI cylinder inspectors because it was interesting to do – because in my other life it was beneficial – and because we could see where this smoke-and-mirrors b-s was going to lead.  Because of U.S.Divers and its followers (DACOR et al.), and the aluminum cylinder fiasco, Scuba-Pro through its outlets, NASDS shops, instituted the VIP program.  They would look into your tank or they wouldn’t fill it.  They were looking for aluminum chips.  Talk about a red herring, heh?  In the beginning, everyone complained about the ‘Global stickers’ and about everyone doing ‘their visuals’.  Well, things ain’t much better now than then, although it sounds more legit.

Here are some facts to face:  steel cylinders fail at the hands of dive shop fill stations and private compressor stations (they are accidentally over-filled – – integrated weights vests can not readily be divested of their lead (maybe the charade works when they’re standing on the shop floor, but it doesn’t work when they’re floating at the surface).

Capt. Fred Calhoun, Gloucester, MA

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3 thoughts on “Tanks and Weights”

  1. As an instructor I have only had to purposely dump weights twice, both had integrated weights and they dumped flawlessly. On the other hand I had to retrieve countless weight belts that simply fell off and not on purpose. In my opinion and experience weight belts as a rule are infinitely more dangerous and more prone to cause accidents.

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  2. I was involved in both the lead and tank business and make the following comments;

    1. As a general rule, divers don’t drop their weights (on purpose) I’ve pulled up more dead divers wearing a weight belt than a weight belts alone.

    2. As a general rule, the dive industry treats cylinders rather poorly. I am sure they are abused on construction sites but ours are abused by the dive stores filling stations. Industrial cylinders are filled by gas handling professionals. Ours seemed to be filled by what has been described as “tank monkeys”. Please consider that the filling rate for high pressure cylinders is 300-600 psi per minute. Crash filling is common and the best way I can describe it so that people understand is to use the 16 penny nail comparison. Put a 16p nail on a 2×4 and take a 22oz framing hammer and push as hard as you can. Nothing happens. Swing the hammer and you can drive it through in one stroke. Crash filling a tank is “swinging the hammer”.
    I can also go on and on about oxygen protocols and overfilling, but you get the idea. A little gas handling professionalism,in this industry, wouldn’t hurt.

    As for 6351 aluminum cylinders, why is the problem concentrated in the dive industry. Of the millions and millions sold to the oxygen and beverage industry, why us? DOT examination have shown that all the “catastrophically” failed cylinders had cracks for at least one hydro cycle and 7/8 VIP’s. I’d say it’s time for a little self examination.

    Off my soap box for now.

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  3. I took PSI training. It opened my eyes. My question is about steel LP tanks that are overfilled. I see it all the time. I never hear of them exploding. Could you direct me to studies on this and or some cases of failure reports? I need to “scare straight” a few folks. Raphael

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