Overfilling LP Steel Tanks -- How bad is it?

[SparticleBrane]

I wonder if they did the recommended PST hydro pre-test on applicable cylinders...

 

[clerickass]

Why overfill? If you're buying tanks, get tanks that hold what you want.

Terry

"Isn't he just so CUTE? Almost makes you want to take him home and keep em!"

Seriously, if we did that, how would we justify the months spent continuing this thread!?

 

[adm3745]

Overfilling is not an issue. As long as you have an understanding of what you are doing and respect it. I'm not gonna take 3800 psi on a reef dive, but I can definately justify taking 3600-3800 on a deep dive or when I will go into a cave. Also don't do that three times a week or leave it stored for a couple weeks with that much pressure.

 

[Rick Christ]

Really? Funny, I've never heard of a single incidence of a steel 72 blowing up from being overfilled. Surely this would be news worthy as fill stations would be destroyed and people would be dying. Do you have any examples, any documented case of this happening? I'd be interested in that. I'm not denying your statement, I just never heard this before.

I have always assumed that steel 72s were over-engineered for their service pressure. This is why it's almost unheard of for them to fail hydro, despite the fact that every one still in service is decades old. I spoke to a hydro guy once who told me he has never seen one fail.

I think that in part, the service pressure of those tanks was influenced by the fact that lower pressure for compressed air was the norm in the 1950s and 60s, and also by the fact that many steel 72s were reputedly used as fire extinguishers, which operated at much lower pressures.

I would be very interested to know the wall thickness and other specific structural information on LP72s as opposed to current 3AA 2400 tanks.

http://www.scubaboard.com/forums/4555547-post27.html

 

[Rick Christ]

Does anyone have a picture of a steel SCUBA cylinder of any kind that failed due to reasonable overfilling (ie not 10000psi or physical damage)?
I spoke with the owner of a hydro facility in the area that handles most if not all of the local hydros and he said he has never seen a steel SCUBA cylinder of any kind explode.

Im not advocating either argument here just looking for pics of the aftermath if one has ever actually let go under pressure.

SCUBA Related Incidents
As Reported by PSI-International, Inc. July, 2001

*Injury Codes: 0=None, 1=Death, 2=Severe, 3=Moderate, 4=Minor
Date Location Type Activity Cause Injuries*
1960 Watertow, NY Steel Filling ? 4
1960’s Canada Steel Stored ? ?
1960’s Florida Steel Filling ? 0
1970’s Oregon ? ? ? 0
1971 British Virgin Islands Steel Filling ? 4
1971-72 St. Kitts Steel ? ? ?
1973 Los Angeles, Ca Steel Filling Corrosion 2,3
1974 Grand Bahamas Alum-6061 Filling ? 4,4
1974 Cozumel, Mexico Steel Filling ? 3
1974-75 Anchorage, AK Steel Rigging Corrosion 1,2,4,4
1977 Hawaii Aluminum Filling Fire 4,4
Aug. 1979 Japan Steel Rigging Corrosion 1,2,4,4
1981 Florida Aluminum Filling Heat 2
1981 Florida Aluminum Filling Heat 3,4,4,4,4
1982 Ft. Lauderdale, Fl. Aluminum Filling Crack ?
1983 England ? Filling Metric Valve 0
1983 New York Steel Stored Corrosion 0
1983 England Steel ? Thread Corr. 2
1984 New Guinea ? Filling ? 0
1984 Hawaii Steel Filling Corrosion 4
1984 Hawaii Steel Stored Corrosion 3
1985 U.S. Virgin Islands Steel Filling Corrosion 2,3
1985 Florida Steel Filling Corrosion 2
1986 W. Palm Beach Florida Steel Filling ? 0
1986 Moline, IL Steel Re-valved Pressure 2
1988 Australia Aluminum Filling Crack 2,3,3,4
1988 Virginia Aluminum Filling Altered Drugs 0
1990 Belize ? Filling ? 0
1990 Key Largo, Florida Aluminum Stored Heat 0
1990 Puerto Rico ? Filled ? ?
1991 Cape Town, So. Africa Aluminum Stored ? 0
1991 Roatan Aluminum Stored on boat Fire 0
1991 Latusis ? Stored in Van Burst Disk ?
1992 Hilo, HI Aluminum Filling ? 2
1993 Pooler, Georgia Aluminum Filling ? 2
1993 Pompano, Florida Steel (Vinyl) Filling ? 0
1993 Egypt (Red Sea) Aluminum Filling Overfill 2
1993 Honduras Aluminum Stored Fire 0
1994 Ft. Lauderdale, Fl. Aluminum Filling Crack 2
Aug. 1994 Calgary, Alberta, Can. Steel Filling Overfill/disk 1,3
Jan. 1995 Florida Steel Filling Metric Valve 2,4,4
July, 1996 Alabama Aluminum Filling ? 0
Aug. 1996 Athens, Greece Aluminum Storage Metric Valve 1,3
May, 1997 Fiji Islands (2) Aluminum Boat Fire Heat Damage 0
May 30, 1997 Tjoeme, Norway Gerzat, 5283 Aluminum Storage ? 0
1997 Jeddah, Saudi Arabia Aluminum Filling Cracking 0
1997 Rio De Janeiro, Brazil Aluminum Val Extrusion Metric Valve 0
1997 Cuacao, NA Aluminum Hydro-Retest ? 0
1997 Cuacao, NA Aluminum Val Extrusion Metric Valve 0
Feb. 1998 Auckland, New Zealand Steel Filling ? 0
Jan. 25, 1998 Anaheim, CA Copper In Use ? 0
Feb. 1998 Auckland, New Zealand Steel Filling ? 4,4
Feb. 1, 1998 Riviera Beach, FL Aluminum Filling Cracking 2
June 4, 1998 Joplin, MO Aluminum Filling Heat Treat Paint 3,4
October , 1998 Auckland, New Zealand Aluminum Filling ? 2
April 19, 1999 Campbell River, B.C. Can. Aluminum Filling Cracking 0
May 1999 Cozumel, Mexico Aluminum Filling ? 0
Aug. 9, 1999 San Diego, CA E9791 Filling Valve Extrusion 2
October 2, 1999 Auburn, CA Aluminum Filling Cracking 0
October 19, 1999 Syosset, NY Steel Filling ? 0
March 17, 2000 Key Largo, FL Aluminum Filling Cracking 2
June 8, 2000 Tobermory, Ontario, Can. Steel Storage ? 1
June 30, 2000 Okinawa, Japan Aluminum Filling Cracking 4
Nov. 24, 2000 Hawaii Aluminum Blending ? 3
December, 2000 Rio de Janeiro, Brazil Aluminum Filling ? 1
February, 2001 Osaka, Japan Steel Val Extrusion ? 0
November, 2001 Sebastion, FL Steel Filling ? 1

 

[JDMerk]

What is this list supposed to mean? Its worthless...
*** does "1988 Virginia Aluminum Filling Altered Drugs 0" mean? and what does it have to do with SCUBA cylinders?

Besides the shockingly lacking documentation and details on this list i'm guessing half these "incidents" have to do with burst disks letting go, o-rings extruding, fire damaged tanks and some tanks being altered by drugs??? Does this constitute some kind of proof of something to you?

 

[WD8CDH]

So I live in Florida & I've noticed my LDS routinely overfills tanks...I wanna buy something like an LP80/85 to be overfilled. My question is..how bad/dangerous is it really to do this?

Not much more or less dangerous than overfilling an HP steel tank by the same percentage.

An HP 100 will be about the same size, weight and buoyancy (as an LP80) at any given fill pressure but won't actually be exceding it's legal pressure until you go over 3443psi.

 

[Rick Christ]

What is this list supposed to mean? Its worthless...
*** does "1988 Virginia Aluminum Filling Altered Drugs 0" mean? and what does it have to do with SCUBA cylinders?

Besides the shockingly lacking documentation and details on this list i'm guessing half these "incidents" have to do with burst disks letting go, o-rings extruding, fire damaged tanks and some tanks being altered by drugs??? Does this constitute some kind of proof of something to you?

Maybe you can understand this info, now (see attached)

 

[mkutyna]

So according to that document, there have been 2 cylinders that ruptured due to overfilling. One was an aluminum and the other was a steel. The steel failed due to "overfill/disk" which might mean that it was overfilled and the burst disk blew. Or maybe it doesn't. We certainly can't tell from reading the document.

Looks like overfilling steel tanks is pretty safe according to that document.

 

[Rick Christ]

So according to that document, there have been 2 cylinders that ruptured due to overfilling. One was an aluminum and the other was a steel. The steel failed due to "overfill/disk" which might mean that it was overfilled and the burst disk blew. Or maybe it doesn't. We certainly can't tell from reading the document.

Looks like overfilling steel tanks is pretty safe according to that document.

I put that list up because of all the experts on this board that are saying that steel tanks don't rupture.

How do you come to the conclusion that only two tanks ruptured because of overfilling?

1. Nov 2001 Sabastion, FL. Steel Filling Killed one
How do you know that this one was not weaken from overfilling???

2. June 8, 2000 Tobermory, Canada Steel Storage Killed one
How do you know that this one was not weaken from overfilling???


I could go on, on and on