The perils of owning LP tanks in the Midwest

[tbone1004]

@KWS it's 1,000lbs weight, not $1000. That would be a problem as just the sphere on my CCR is worth over $1k... 1,000lbs gross weight

 

[Divin'Papaw]

Exaggerated counterpoint: If I take my 60 gal. shop compressor tank diving, I can have about 80 cubic feet (at compressor-nominal 150psi or 120 if I jack it to rated max of 225psi) to do a nice reef bimble. Unfortunately, that doesn't really work on a number of levels.

Caring/competent humans tend to select things for efficiency. For dive cylinders, that is going to be a series of tradeoffs between gas capacity, buoyancy characteristics, cost, weight, size, durability, "fillability", etc. And when more utility can be obtained by cramming more gas in while holding the other factors the same, well that is more efficient ...

At least in my experience, "we" also tend to make personal evaluations of risk profiles for certain circumstances that may be less or even more conservative than those governmentally dictated (typically in a Lowest Common Denominator sort of analysis i.e. for folks who are anti-Wobegonean)

In my mind the "reasonable overfill" is very akin to the fact that (barring jams or adverse conditions) the majority of highway traffic seems to consistently travel at a speed 5-15mph over the posted speed limit. It is simply more time efficient. (Which is why we use vehicles of all sorts instead of walking everywhere.)

I'm honestly not really following your point. Sorry.

When we dive we bring with us the gas we need to survive underwater. The fundamental question is "do I have the gas I need plus a reserve?" Certainly we select the tank(s) we use based upon buoyancy and volume characteristics but what matters is whether we have the volume of gas we need or not.

Getting worked up about whether I get 3000 psi in my LP85s or 3442 in my HP100s is a fools errand. I dive HP100s primarily. Sometimes I get a solid cool 3600 psi fill and sometimes they cool to 3300-3400. But what matters is do I have the gas to do the dive??? Anything extra is just left in the tank as the base for the next fill, right?

 

[formernuke]

consistently travel at a speed 5-15mph over the posted speed limit.

Around here people get pissed and tailgate, flash lights etc if you aren't going at least 30 mph over the posted speed limit.

 

[StefinSB]

I'm honestly not really following your point. Sorry.

When we dive we bring with us the gas we need to survive underwater. The fundamental question is "do I have the gas I need plus a reserve?" Certainly we select the tank(s) we use based upon buoyancy and volume characteristics but what matters is whether we have the volume of gas we need or not.

Getting worked up about whether I get 3000 psi in my LP85s or 3442 in my HP100s is a fools errand. I dive HP100s primarily. Sometimes I get a solid cool 3600 psi fill and sometimes they cool to 3300-3400. But what matters is do I have the gas to do the dive??? Anything extra is just left in the tank as the base for the next fill, right?

It’s not of you dive different tanks than your buddies

 

[NAM001]

@KWS it's 1,000lbs weight, not $1000. That would be a problem as just the sphere on my CCR is worth over $1k... 1,000lbs gross weight

And I think you prove my point. one shop i dealt with said he could not transport over 10 tanks for a similar reason. he cited 10 tanks did not constitute a non commerce transport and that any more than 9 tanks required a bill of laden and full complliance with DOT because the wuanmntity constituted a commerce move . that explaination like all the others is just one more in the bucket of those that desire to interpret to their advantage. What was more entertaining was that he said it used to be 1000$ of tanks but since 3-5 tanks now would equal that price the standard changed to 10 tanks. The justification was many tanks is more than what can be reasonable used in a personal outing . Then you hit the meat of the matter where it was the ins company that defined the conditions and you get one more layer of confusion. I have had people say they can put 15 tanks in a truck so long as there is no more than 10 in one location IE 9 in the bed of the truck and 6 in the front seat Then of course there are the arguments that if you can put all you want in the back of a truck with out strapping them, that it is not a commercial transport and that strapping them makes it commercial. The topic is entertainment at least. And we cant ;forget things done by those not employed.. " is not the shop doing it, it is a private indivudual doing it". Owners kids doing VIS's or filling tanks does not have to comply because they are not a paid employee. Lots of crap out there. And even when you post the verbatum CFR it is challenged as whether it applies to a preticular condition or situation. Here is another one. You can not ship a vessel that is out of hydro. Any common sense says that is BS. another is you cant ship a presurized vessel if it is out of hydro. The truth is you can not pressurize a vessel out of hydro and then ship it. I have had shops say it is illegal to fill a tank with Air IF IT HAS A NOTRIX STICKER ON IT. Then the truth comes out. they say they have to vent down and remove the valve to guarantee an empty tank and then since the valve was removed, it will need a Air VIS before they can refill the tank because a Nitrox vis is not good enough for air. AGAIN LOTS OF ENTERTAINMENT OUT THERE.

 

[tbone1004]

@KWS I have never seen anything in writing from any regulatory body about quantity of bottles or dollar value of bottles. I have only ever seen the mass of bottles and definition of commerce.

 

[NAM001]

I'm honestly not really following your point. Sorry.

When we dive we bring with us the gas we need to survive underwater. The fundamental question is "do I have the gas I need plus a reserve?" Certainly we select the tank(s) we use based upon buoyancy and volume characteristics but what matters is whether we have the volume of gas we need or not.

Getting worked up about whether I get 3000 psi in my LP85s or 3442 in my HP100s is a fools errand. I dive HP100s primarily. Sometimes I get a solid cool 3600 psi fill and sometimes they cool to 3300-3400. But what matters is do I have the gas to do the dive??? Anything extra is just left in the tank as the base for the next fill, right?

IMO that is one side of the coin. it is a personal safety thing to have enough air for a dive. it is a public safety concern if the tanks are not being used or handled as intended. that difference is the battle ground in all these arguments. Manya say their personal tanks can not hurt teh public and that makes them exempt. I fully understand both sides of the fight. It does not help when regulations go over board. yes it makes the public safer. but how safe is safe enough. Can 100% be achieved??? any vessel that can be tested at 5k can not be hurt by a slight over fill. Yet it is a violation to do so. AND YET ANOTHER YET IS APPLIED It is ok to over fill per PSI vaslaue if when it cools to 70f it is then in spec. There is so much conflict in logic involved, too much one rule fits all. There is too much wiggle room that promotes ignoring or challenging of regs. Too many shops do stupid stuff like saying that there policy is that if a al80 has 2700 or greater in it it is a full tank. at 5psi per degree ,, that tank had to have had 3000 psi at a temp that is 60 degrees over 70F. And why because they claim it is illegal to fill more than 3000 psi. CFR clearly states otherwise. And then if a tank does cool to that PSI then the tank was being filled too fast IAW CFR's 600 psi per minute. IN GENERAL ......NO ONE FILLS CORRECTLY. Then you have those that say if you can water bath or use cooling for the tank it is a violation. Nonsence as far as I know. Their arguments are based on,,,,,cooling hides the symptoms of high fill rates which is heat and only people who do fast fills use cooling. SOME WHAT GUILT BY ASSOCIATION,,,,,,,,,NO CFR against that ( the hiding part any way). I asked the question whether it was OK to cool the tank prior to filling. (dark tanks get hot sitting in the sun prior to fill) That question did not receive even a cool welcome. It was cold for sure. That is the problem with one rule fits all AND AGENDAS.

 

[tbone1004]

@KWS my general rule is that per the CFR I am allowed to fill to 120% of capacity if the tank hits 131F. The tanks almost always hit that when filling especially if they are nearly empty and if you do that, then they should cool to roughly service pressure.
2475=>3100
2640=>3300
3000=>3750
3500=>4400

What do I do? It depends, but I think if you're filling at 600psi/min and the tanks are relatively empty, then setting the regulator to 20% over is pretty spot on IME.

 

[NAM001]

Probably not. It could have very well came from someone that had additional state or local transportation regs governing them. They then speak as if it was federal issued and not more local generated. Or they dont include the authority and it turns to gospel form lack of necessary information by those that pass it on.

Your tank psi's are a bit high for what gives me the final wp results but I charge slower, not by intent perhaps but because it is easier for me to charge many and not single tanks.
2475=>3100
2640=>3300
3000=>3750
3500=>4400

Al tanks I do not over fill for my self or others. they get 3250 hot and the charge ends.
My 2475's I fill to 2800 with he over fill, 2640 to any where form 3k to 3400
and I dont have any 3500's at all. If I did i probably would not fill them past 3600. NO sound reason why other than general talk oABOUT HP tanks do not handle over fills like lp tanks can. Its precaution based on UNSUPPORTED RUMORS. I NEVER BOTHER TO DIG INTO IT BECAUSE I HAVE PLENTY OF OTHER TANK OPTIONS INTHE GARAGE AND OWN NO 3500'S

 

[tmassey]

Or it can often times just as easily be: “Let me tell you why the federal government won’t let me do that thing which I never intended to do, but need a better excuse than I don’t want to.”

Insert overfill, schlep tanks, fill tanks faster, “bad” aluminum, old aluminum tanks, etc.

I think self interest fits Occam‘s Razor at least as well. Plus appeal to authority.

ETA: VIP stickers. Very, very much VIP stickers.