Question about my new steel tank (new to me).

[scubadada]

A LP 72 will definitely provide you with less air than a AL80.

Unless also filled to 3000 psi

 

[rnln]

A LP 72 will definitely provide you with less air than a AL80.

Let me make sure, even though it is 3" longer than the usual LP72, 28.5" long, and with a +?

 

[ScubaBunga]

Yep it’s a Norris steel. I have 2-3 in my workshop planned for hydro in summer. I have over a dozen old steels for me and my boys. Finding hydro that will plus has been a painful search. I might have found a place but won’t know until I take them in. The valve should be standard unless it’s a real oddball, so swapping out for new valve should be no problem. Using the j-valve is also not an issue, just keep the valve down and use an spg like you would with a new tank. Store the rod for when a vintage collector wants a complete set. I have 4-5 jvalves. Two in current use, one of which is a 1/2 inch with valve handle on top (I valve?). It is an old tank so some shops have erroneous belief that old tanks are bad, so just be aware if going to other shops. I usually call places I’m traveling to if bringing my tanks. So far I have not had any issues, but if you search the boards you will find other stories. Happy diving!

 

[SandyRobinson]

So, I love my old school 72s.... A little pro/con for you;
Weight- a smidge lighter, but less buoyant. Results in less lead on belt (approximately 4 to 6 lb)
Capacity- at 2250 they are only 65 cf. However, many shops fill lp steels to 2600 without even looking at what is stamped. If you have a shop that does "cave fills" at 2800 they are a true 80 cf
Trim- they don't get as floaty in the tail as they empty.
Tank ownership- keep it full and dive when you want without having to coordinate picking up or returning a rental.
Value- have to do the math on price difference between a fill and a rental at your shop. For me the math breaks even at about 20 dives a year per tank I own. I may not make those numbers, or I may far exceed them... For me it's close enough the convenience makes it worth it.

Your milage may vary....

Some good comments here. My daughters dropped 4 pounds using my 72s. Next time they will drop 5. Also, assuming you have the rest of your equipment, nothing like having a tank(s) ready to go!

 

[James79]

Let me make sure, even though it is 3" longer than the usual LP72, 28.5" long, and with a +?

Only way to be sure is to measure internal volume, then do the math off of the service pressure. The + means it was ok'd for a 10% overfill, unfortunately manufacturers of steel tanks include that in there designation. So your tank has a sevice pressure of 2250, but was plus rated resulting in a nominal 72 cf at 2475 psi.
Most hydro shops don't renew the + on old steels, but we good go deep into metallurgy on why "cave fills" are safe with a steel but not on aluminums. Long story short, even as a 2250 psi 65, it would be a great shoredive tank. At 2800 psi it beats an al 80 6 ways from Sunday!

 

[grf88]

I think we have to agree to disagree one this. Well you've wasted your efforts on me my friend.

I am not really concerned about you but I am concerned about newer divers that read to turn it back a little because it will save the seat and remember that they heard turn it back a quarter turn somewhere. These are the ones who may find themselves at depth with their regulator not providing any air. You are welcome to do as you like but do me a favour and don't promote the idea of turning the valve back, you may just save someone's life. All agencies teach against this practice but there are some in the industry that just don't get it and still promote it. Can it happen, I have first hand experience when after I had turned my tank on and tested it a divemaster on the charter turned it off and back on a quarter turn. At about 60 ft. the reg stopped providing air. Fortunately I was both experienced enough to recognize the problem and simply reached back to turn it on. I am not confident that many newer divers would be able to easily do either in a stressful situation.

 

[rnln]

So, I love my old school 72s.... A little pro/con for you;
Weight- a smidge lighter, but less buoyant. Results in less lead on belt (approximately 4 to 6 lb)
Capacity- at 2250 they are only 65 cf. However, many shops fill lp steels to 2600 without even looking at what is stamped. If you have a shop that does "cave fills" at 2800 they are a true 80 cf
Trim- they don't get as floaty in the tail as they empty.
Tank ownership- keep it full and dive when you want without having to coordinate picking up or returning a rental.
Value- have to do the math on price difference between a fill and a rental at your shop. For me the math breaks even at about 20 dives a year per tank I own. I may not make those numbers, or I may far exceed them... For me it's close enough the convenience makes it worth it.

Your milage may vary....

sad to hear all this after I have my mind set to this light tank. Just had a talk with the tech who do the hydro near here, nice guy but hard to get too. Seem like he has the best price
- He will give the + rated if it past. And if it past I can do 2475 psi. I asked about 2700psi. He said not recommended.
- He is primarily for fire protection so he won't take care of the valve. I will get new valve anyway, either from James or VDH
- He won't certify VIP, but he will personally visual check for crack and rust inside, but again he won't certify his check. Do I need VIP stamp to get filled?
- He won't tumble since his tumbling machine just broke down. Question is if I need tumble? Can I just take a peak after taking the valve off to see if any lining peel off or rust? I should check prior to taking it out anyway right?

If all the above is ok, it will cost me all around $80 total. Worth to own it. If it cost more and without the +, I don't think it worth it. Any thought?

 

[AfterDark]

I am not really concerned about you but I am concerned about newer divers that read to turn it back a little because it will save the seat and remember that they heard turn it back a quarter turn somewhere. These are the ones who may find themselves at depth with their regulator not providing any air. You are welcome to do as you like but do me a favour and don't promote the idea of turning the valve back, you may just save someone's life. All agencies teach against this practice but there are some in the industry that just don't get it and still promote it. Can it happen, I have first hand experience when after I had turned my tank on and tested it a divemaster on the charter turned it off and back on a quarter turn. At about 60 ft. the reg stopped providing air. Fortunately I was both experienced enough to recognize the problem and simply reached back to turn it on. I am not confident that many newer divers would be able to easily do either in a stressful situation.

Anything done wrong or incorrectly can be dangerous in this sport. If the valve is backed off a bit after going to the stop and nobody mess with it then no harm no problem. If a diver does it wrong or lets someone else check his gear that doesn't know what they back off on the valve then yes a problem a serious one can follow. Lots of things can happen diving doing things correct and taking responsibility for yourself helps to reduce those things.

 

[Dizzi Lizzi]

I have a 72 with a J valve. I don't have the rod but I just dive with it in the down position and use my spg like normal. The only issue I have is the 0 ring is a weird size that doesn't come in the save a dive 0 ring boxes, so I have to go begging at my LDS to find the correct size. They always find one for me.

 

[rnln]

I have a 72 with a J valve. I don't have the rod but I just dive with it in the down position and use my spg like normal. The only issue I have is the 0 ring is a weird size that doesn't come in the save a dive 0 ring boxes, so I have to go begging at my LDS to find the correct size. They always find one for me.

May I ask a further question? Does tank valve, j-valve, need to be serviced after a certain time? Can you find parts available beside the o-ring you are talking about?
Thanks.