Ron
Regular Diver
Posts: 41
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Post by Ron on Feb 21, 2006 5:49:23 GMT -8
Nemrod
I think I would like to learn more about Nemrod, o never mind I can find all I need on Yahoo.
Have a good one
Ron
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Post by Linda on Feb 21, 2006 8:43:26 GMT -8
Man this thread is idiotic we can go on and on on this topic with no practical out come. I think this thread is far from idiotic. I see a lot of practicality and value in it and I would hate to see it degrade. Going back and forth is what it's all about in a respectful discussion. It's only when one person tries to force himself on another or becomes overly emotional that things go awry. To say the thread is 'idiotic' is a bit arrogant, because one can assume you mean all but your own input... So unless you want to consider yourself an idiot as well, please stay on track and let others have their say. I would hate to have emotional comments ruin an otherwise fascinating discussion.
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Post by SeaRat on Feb 21, 2006 8:54:39 GMT -8
Nemrod,
I'm sorry to hear that you've deleted your posts. That makes the discussion somewhat hard to follow. It would be good if you (or Linda) could re-instate those posts (see below).
Ron,
As a new member, please show some respect for the people who've been here a while. Steel 72s are very pertinent to vintage diving, as they were the tank of choice for many years. They still have some advantages over the newer AL and steel HP tanks (especially concerning buoyancy characteristics of a steel 72 verses a HP steel tank). Many of our vintage divers dive without BCs, and need to know the buoyance of the steel 72 for weighting purposes, which is where this thread started. Yes, there are problems with steel corrosion, but they are handleable. I have two steel 72s now, one that I've had since the early 1980s. I have two steel 42s that date to the same period, and they (the 72s and the 42s) are wonderful in the water; balanced, streamlined, and with the capasity that is about right for sport diving.
To all,
I am still studying, but felt that this was an important enough topic to weigh in on.
Enjoy your vintage equipment,
John
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Post by Linda on Feb 21, 2006 9:18:42 GMT -8
I too, am sorry that James deleted his posts, not because the thread might be hard to follow so much, but because I think what he had to say had as much value as anyone else... Unfortunately the forum has no "recycle bin" so what is deleted is gone forever and cannot be reinstated. Ron (Hearn) registered recently, but as a guest he's been around forever. Neither here nor there really, but I don't think the length of time here should have anything to do with treating each other with respect... It should be something we all try to do automatically.
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Post by SeaRat on Feb 21, 2006 9:44:19 GMT -8
I've seen Ron Hearn's posts before, but assumed that this was a different Ron. 'Sorry about that; that's what you get for making assumptions. I just haven't seen this type of behavior here before...
John
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Post by duckbill on Feb 21, 2006 10:01:53 GMT -8
I thought it was a different Ron, too! "Ron"s posts on this thread seemed out of character compared to Ron Hearn's posts on previous threads. I think Ron was just trying to reiterate the importance of regular cylinder inspections. It's been interesting reading, but maybe Linda could move this thread to SCUBABoard's "Tanks, Valves, and Bands" topic
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Post by luis on Feb 21, 2006 10:20:48 GMT -8
I am sorry of some of the turns this thread has taken, but in general I think some of the information in it is very valuable. I don’t want to add fuel to the fire, but this thread reminded me of information I have that I think is important for me to share. The link below leads you to a Bulletin D100-E that came from the engineering department at Pressed Steel Tanks (it is a PDF file). The bulletin describes the hydro pre-test procedure (also known as round-out procedure) that is recommended for steel tanks. www.vintagedoublehose.com/downloads/PST-D-100.pdfvintagedoublehose.com/forum/viewtopic.php?t=549PST is the manufacturer of many of our steel 72's tanks, but the hydro test procedure described in this bulletin applies to all galvanized steel tanks. If you are the owner of a steel tank I think it is VERY IMPORTANT that you take a copy of this bulletin to a hydro tester when you take your tanks for hydro (and /or make sure he follows the pre-test procedure). Perfectly good tanks have been failed during hydro testing when this procedure was not followed. The probability of a steel tank failing even if the pre-test procedure is not followed is low, but if that tank fails the results are final. You have no recourse; the hydro tester is required to condemn the tank. The procedure is within the allowable DOT regulations as can be seen in the bulletin, but the hydro tester is not required to perform it as required by the manufacturer. I am personally aware of hydro test facilities that did not follow this procedure. Below is the text from that bulletin. I recommend you down load the PDF file and print it in its original format.
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Ron
Regular Diver
Posts: 41
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Post by Ron on Feb 21, 2006 10:27:08 GMT -8
Hi
Yes! its me Ron Hearn recently fully registered. My contribution to this thread was simply trying to get the message across that you just can't go wrong when you have your tanks hydro tested and inspected by a facility that's sanctioned by DOT or CSA. I just don't understand why some vintage cylinder owners would think differently and continue to use a tank that has not been hydro tested past its due date as its such an inexpensive safety procedure to carry out. I don't think I was out of my regular character on this topic as some serious topics warrant debate more than others. I'm a stickler for safety spending most of my life as a Mixed gas sat diver in the off shore oil industry were I've seen little things that one person ignores hurt allot ot other down the road. I apologize if I insulted any one in any way and I accept your apologies also so now can we all shake hands and talk vintage..
Ron
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Post by duckbill on Feb 21, 2006 13:42:27 GMT -8
Yeah, James, quit deleting your posts. And never, ever delete your original thread-starting post after it's been up long enough to be seen! When I saw this thread a while back, I had no idea what the conversation was supposed to be about. No wonder the topic got side-tracked. It's all your fault
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Post by JES on Feb 21, 2006 14:18:07 GMT -8
This has been one of the most enjoyable, highly informative, and spirited posts in a while. Thanks to everyone for sharing all of your collective information. It is truly educational. I still stand by my earlier statement. This has been one of the most informative posts in quite a while. Nothing quite compares to having many different opinions coming together on a common subject. I'm glad that the misunderstandings have been ironed-out. Remember, when all else fails we can all agree to disagree (peacefully).
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Feb 21, 2006 14:40:31 GMT -8
Jeepers,
Missed out on all the fun and guns........now that the smoke has cleared some what , I found the post that Allan did on old tanks.........
Noticed one detail.....it stated 42's were 38's filled to 2068 psi...........didn't know that.....thought they were 38's at the 10% overfill.......can anyone elaborate on that?
I have two sets of twin 38's.......one set are my voits at 1880 psi indicated on the bottles and the other are my USD's at 1800 indicated on the bottle........
Are they both 42's at 10% over or just 38's?.....of course the USD's would only be 1980 psi at 10% over......but I'd push them to 2000
as a comment: On my 72's.........negative bouancy for them would be more than what is listed empty, cccccccccause I would have approx. 400 to 500 psi still in there.....I never breath them dry......not healthy.......
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Post by duckbill on Feb 21, 2006 17:22:26 GMT -8
Noticed one detail.....it stated 42's were 38's filled to 2068 psi...........didn't know that.....thought they were 38's at the 10% overfill.......can anyone elaborate on that? I have two sets of twin 38's.......one set are my voits at 1880 psi indicated on the bottles and the other are my USD's at 1800 indicated on the bottle........ Are they both 42's at 10% over or just 38's?.....of course the USD's would only be 1980 psi at 10% over......but I'd push them to 2000 My USD twin 38s are 1800 psi only, meaning 38 cu.ft. at 1800 psi. There is NO PLUS RATING on the original factory hydro on mine. Check yours. Maybe they are different. But, a cylinder which is plus rated at the factory indicates that the cylinder will hold it's rated volume at that 10% overfill as designed. No plus rating means it will hold the rated volume at the actual pressure shown. Most of us are really just guessing the cylinder's volume when it comes to calling them 38s 44s 45s 50s etc. The BEST method I have found (short of filling them with water and measuring the volume to calculate the volume at pressure- NOT recommended with steel cylinders for obvious reasons), is to use a crossover manifold or whip connecting a known cylinder (a 71.55 cu.ft. cylinder at 2475 psi, for example) to your unknown, empty cylinder(s) , equalizing the pressures, and calculating the volume of your unknowns from the resulting equalized pressure. I can provide the formula if anyone wants it. as a comment: On my 72's.........negative bouancy for them would be more than what is listed empty, cccccccccause I would have approx. 400 to 500 psi still in there.....I never breath them dry......not healthy....... ....AND, almost all listed buoyancy characteristics for cylinders DO NOT include the weight of a valve. A steel 72 is rated 3.5 lbs. buoyant empty. Add 1 pound for air ( 450 psi reserve/ (2475 psi/71.6 cf) X .08 lb/cf = 1.04 lbs ) and 2 lbs+ for a j-valve and regulator, and there you have it......near neutral when "empty" (450 psi reserve)!
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Feb 21, 2006 18:10:09 GMT -8
Duckbill
Looking at my USD's.....original hydro is in 61 with a + next to it.........same for my voits original hydro is 61+
Looks like they are 38 cuft no matter how I look at them.
Now my twin 45's are a different matter, bigger slightly in the shoulder, heavery by far and 2250 psi rated.
I need no weight with them and using a 1/4 inch wet suit.............then again, I tend to sink with or without aid of weights tanks etc...............
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Post by Broxton Carol on Feb 22, 2006 3:57:31 GMT -8
I pump my tanks the 10 percent over and never had any problem. Get you a compressor and get the government out of your life. Inspect the interior, and exterior, and get the greedy dive shop out of your life. I have saved $1200.00 in headaches and gas! Ill pump a few today with my vintage 1959 cornelius model 42017 compressor just for relaxation. Have a nice day ya' all. ;D
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Ron
Regular Diver
Posts: 41
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Post by Ron on Feb 22, 2006 6:31:29 GMT -8
Steel tanks usually do not qualify for plus signs after the second and subsequent hydrostatic tests.
Ron
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