O2 tank explosion

[swamp diver]

I'm not sure that the comparison to bumping or knocking over a medical oxygen tank is a fair one. In a medical tank the valve is vertical without the tortuous pathway found in a scuba valve and the medical valve does not have a large soft rubber handle which sticks out the side where it can accidentally get rolled on if bumped or if the tank falls over.

Additionally in the health industry most jurisdictions do not allow high pressure medical oxygen tanks to be stored loose where they can accidentally fall over. They are kept in storage racks to prevent such accidents. Also maximum fill pressure for a medical O2 tank is 2400 psi.

There are other problems with the scuba valve used for 100 percent O2 such as the nylon seat which is not oxygen compatible and in this case the unfortunate use of a non-oxygen compatible lubricant on the neck threads.

If the valve was not cleaned as part of the annual servicing then the nylon seats can collect compressor lube oil and filter dust over time if the tank is also used for partial pressure oxygen mixes.

It is time someone in the scuba industry designs a proper valve (i.e. vertical) for this specific application in order to reduce one of the risk factors which might contribute to such incidents. There was a fatality in Florida a decade where an O2 tank fell over and killed the woman filling the tank. HP oxygen tanks should be stored in a rack during the fill process and when not in use.
Cylinder incident in Luraville, Florida - Luxfer: Setting The Standard Worldwide

Glad to hear that the photographer and his wife have moved forward from what must have been a very traumatic experience.

 

[mselenaous]

This article says the deco O2 bottle exploded from the presence of Silicon lube in the neck & valve put there by an untrained tech who did not understand the incompatibility of that lube with O2 essentially contaminating the tank after cleaning.

 

[kafkaland]

Perhaps a larger question of standards in handling compressed gases: I occasionally work in a research lab setting with compressed gases, and the rule is that every tank, no matter what is in it, has to be strapped down so that it can't fall over. Or, when it's transported, have a steel cap over the valve stem to protect it. We would be in a world of hurt with OSHA if we violated these rules. Then, I got into scuba diving, and I was surprised how cavalierly we handle our tanks, compared to that. Yes, we make a point of bungeeing them in on the boat, but that seems to be more to prevent them from hurting anyone by them being big and heavy, and not so much the risk of knocking the valve stem off. Otherwise, we bump the tanks around quite a bit. Now, does that mean the OSHA workplace rules are overly conservative, as I don't hear often (except in this particular freak accident case) of exploding scuba tanks? And, why wouldn't a fill station be covered by workplace rules, and you'd never see a tank that isn't secured around?

 

[tbone1004]

part of the reason for the big tanks is more for personnel safety due to how heavy they are and how easy they are to tip over. The valve protectors are nice, but not really needed. This accident would have been prevented by proper O2 cleaning of the tank and has nothing to do with the tank getting knocked over. It would have happened on a dive boat or in the car, first metal to metal contact and any sort of velocity and it would have popped. The comparison to the med O2 is fair because this had nothing to do with the valve aside from it being contaminated. If you look at the pictures, the valve is fine, and the valve was not impacted during the fall, it was the shock from the tank hitting another tank that caused the explosion. You could have had a capped medical valve on there and it would have done the same thing.

 

[DandyDon]

Perhaps a larger question of standards in handling compressed gases: I occasionally work in a research lab setting with compressed gases, and the rule is that every tank, no matter what is in it, has to be strapped down so that it can't fall over. Or, when it's transported, have a steel cap over the valve stem to protect it. We would be in a world of hurt with OSHA if we violated these rules. Then, I got into scuba diving, and I was surprised how cavalierly we handle our tanks, compared to that. Yes, we make a point of bungeeing them in on the boat, but that seems to be more to prevent them from hurting anyone by them being big and heavy, and not so much the risk of knocking the valve stem off. Otherwise, we bump the tanks around quite a bit. Now, does that mean the OSHA workplace rules are overly conservative, as I don't hear often (except in this particular freak accident case) of exploding scuba tanks? And, why wouldn't a fill station be covered by workplace rules, and you'd never see a tank that isn't secured around?

We used to be horrible on our farm about ignoring what few Osha rules existed in our life back then, worse - removing safety shields and leaving them off for easier work. We survived long enough to grow to appreciate most of them.

What we thought we knew about Oxygen & Acetylene tanks we learned from other farms and from local blacksmiths, with similar casual attitudes. Our supplier would not accept empty tanks for exchange unless the caps were securely in place tho, so we almost always had them on when transporting - altho we seldom strapped them down. Never heard of one exploding, but then their periodic inspections were probably more professional than many scuba tanks experience.

Did you see this week's thread: http://www.scubaboard.com/forums/accidents-incidents/490662-tank-explosion-kills-one-cozumel.html

 

[wolfgangmob]

We used to be horrible on our farm about ignoring what few Osha rules existed in our life back then, worse - removing safety shields and leaving them off for easier work. We survived long enough to grow to appreciate most of them.

What we thought we knew about Oxygen & Acetylene tanks we learned from other farms and from local blacksmiths, with similar casual attitudes. Our supplier would not accept empty tanks for exchange unless the caps were securely in place tho, so we almost always had them on when transporting - altho we seldom strapped them down. Never heard of one exploding, but then their periodic inspections were probably more professional than many scuba tanks experience.

Did you see this week's thread: http://www.scubaboard.com/forums/accidents-incidents/490662-tank-explosion-kills-one-cozumel.html

I grew up on a farm (90's and early 00's) and helped my dad with torch cutting and even did some myself, our tanks were on dolly carts with locking wheels and had bars around the tank which was strapped in, came in handy when a summer farmhand knocked one over, the tank was fine but it jerked the torch my dad was holding but it thankfully didn't injure anyone. We were more concerned about crop dust and oil catching fire than the tanks usually and we tried to keep all torch cutting to the shop but did have to go mobile to work on pig pens.

 

[John C. Ratliff]

I have about 35 years in the occupational safety and health fields, and in industrial hygiene. While many consider OSHA regulations a pain, please remember that they are "written in blood." OSHA also writes and publishes Letters of Interpretation, and this one on "Storage and Use of Compressed Gas Cylinders" is pertinent to the discussion we have here.

"...The standard further states, in §1910.101(b), that "the in-plant handling, storage, and utilization of all compressed gases in cylinders . . . shall be in accordance with Compressed Gas Association (CGA) Pamphlet P-1-1965. We note that there are more recent versions of the industry consensus standards that are referenced in §1910.101.2 If the more recent consensus standards address hazards associated with compressed gases that are not addressed in the CGA pamphlets referenced in the standard, §1910.101, §1910.1200, or any other applicable OSHA standard, the more recent consensus standards may provide support for a citation alleging a violation of the OSH Act's general duty clause, 29 USC 651(a)(1). If an employer is not in compliance with the requirements of an OSHA standard but is complying with the requirements of a current consensus standard that clearly provides equal or greater employee protection, the violation of OSHA's requirement will be treated as a de minimis violation. De minimis violations are those having no direct or immediate relationship to safety and health and result in no citation, penalty, or requirement to abate..."

SeaRat
John C. Ratliff, CSP, CIH, MSPH