CNG Tank Failure in Los Angeles [Merged]

[larrycng]

About 5pm this afternoon there was an explosion, in Pasadena, Ca. while a CNG Linnen delivery truck was being refueled. Three people were injured, one seriously with lower extrementy injuries.

There was very little information given on the TV report. The film showed a cylinder, black in color, laying on a sidewalk which appeared to be across the street.

That is all the information I have at this time. The station is www.abc7.com and then check for the Pasadena explosion. The company is Linn an industrial laundry company.

Lets all be careful and have our systems safety checked regularly

Larrycng

[freedml]

Just watched the story. A tank which looks to be in the 8-10 gge range was blown high in the air and across a busy street, landing about 150' away. Not too many other details. Two seriously injured, one not seriously injured.

[Curtis]

I just saw on the 10pm news that a California Linen Services delivery van had a tank blow while refueling. No one died but 2 were injured, one very seriously. The news reported that the company has been using cng in their fleet since 1973 without incident.

The vehicles are UPS style, medium duty, delivery vehicles that appear to be fairly old from what I could see on the report. They showed another of the vehicles and the tanks were mounted underneath the sides of the vehicle and were clearly not shielded.

I suspect that this will come back to a damaged, possibly even expired tank. It's unfortunate that these events occur. As with other such tank failures in recent history, the majority in work vehicles, it has been a case of failure to have the tanks inspected for damage, usually caused by a caustic substance damaging the tank.

I doubt that the tank placement, assuming it's the same in the vehicle in question as it was in the one they showed on TV, that that would be the case here. Perhaps road debris could have been the culprit, since the tank was fully exposed to anything thrown up underneath the vehicle.

I'm sure we'll get the full details over the next few days and weeks.

[cnghal]

Curtis,
Thanks for the heads up. I wonder if anyone we know will be investigating this.
Here's the story with video:
http://www.nbclosangeles.com/news/local/Two-Burned-in-Explosion-at-Pasadena-Building.html

Wow!!!!!!

[ijustride]

Jeez, that's right by me! Just a few blocks up the road. Hope they're ok.

[freedml]

3 injured total, two in the hospital, one critical

[smwalker]

Will there be any report made public on this event? Is there usually? Is there a way the public can get the results of the investigation?

Thanks

[freedml]

NHTSA will almost certainly put out a report in 6+ months.

[afvman]

Larry/cng et al,

Usually, CVEF will get involved on behalf of the industry and send in an investigator. We'll see.

If Curtis is right (1973???) and it's the original installation, it's gotta' be out of date???

I wonder if it's an EDO???

afvman/Bill

[OhMyGas]

would it make sense to include the tank inspection as part of a car's registration renewal?
Just like a smog-check in CA? the smog-check is every other year and the tank inspection would be every 3 years - without a valid inspection, no registration.

[larrycng]

Bill, you and I are thinking along the same lines, from the shape of the dome and end boss I would agree EDO. I thought they were phased out a long time ago except for the one I had at the college (I think it expires this year). As of about 18 months ago LAMTA was still running some of the EDO's in Division 8 in the San Fernando Valley -- and they had the metal heat conducting straps!

I wounder when they were last inspected?

Larrycng

[Highmarker]

I would have to agree on the EDO identification of the tank. It definitely looks like a Type IV and not Lincoln.

[Franz]

Hmm, an EDO tank? A UPS type vehicle? Putting two and two together, I feel this is a surplus UPS vehicle circa around 1997, when UPS was using EDO tanks. This is about the time EDO had their most failures and were pulled. At one time, UPS was a major user of the EDO cylinders.

Gut feeling tells me that this MIGHT be a refurbished UPS vehicle that MIGHT have been either wrecked and rebuilt, or was missed in the recall.

I remember that this EDO situation in 1997'ish almost shifted UPS away from alt fuels altogether.

If anyone gets a close look at the truck, see if there is any brown paint anywhere!

Franz

[rellimr]

Does anyone know for sure if this a Type IV tank? From the picture I saw on the Star News website it looked a bit like a Type III - hard to tell for sure.

If it is truly an old EDO tank then it is Type IV for sure - can anyone verify if it is an EDO, or a Lincoln (from before they had their aluminum tube stuff perfected).

[cowboy]

am I missing something the tank landed across the street ? If parts of the tank landed across the street I could understand. but the whole tank must not have been mounted well as the mounting gave up. I know there is a lot of power stored in the tank but this is why we biuld heavy mounting brackets and bolt them to the frame .

[freedml]

It was pretty clear from the news report footage that an intact tank landed across the street. I would theorize that there were multiple tanks and one ruptured sending this one across the street.

[Lakewood90712]

I know there is a lot of power stored in the tank but this is why we biuld heavy mounting brackets and bolt them to the frame .

My gustimate of the pressure energy release of a full 10 gge would be approx 108 million foot/pounds all in a split second :eek:. Even the best brackets , bolts and backup plates would not hold that.

[cowboy]

I never thought of it as foot lbs more like thrust and = and opposite reaction as the gas comes out should of turned the truck over but not come loose I think I might have to do some more testing with old tanks and brackets anyone have any idea how to cause a catastrophe failure of a tank I have shot holes in them and nothing other than lots of gas . other than to much pressure I dont have any idea think I will try this so send your ideas on how:)

[cngmike]

Please be careful a group of engineers in Canada killed themselves doing rupture testing several years ago.

As I remember the strength ratio of hoop tanks goes as fallows, hoop or wrap/liner
Type II 50/50
Type III 60/40 to 80/20
type IV 100/0

Dave correct me If I am wrong.

[larrycng]

Mike, I don't think there has been a range in the liner to overwrap ration. It has been 20% liner to 80% overwrap. The only variation I can recall is in a training film which stated 85% overwarp and 15% liner. Otherwise your are correct

Larrycng


An aplolgy to all, Since I got side tracked and am not "Dave" I shouldn't have commented on the message.

Larrycng

[Curtis]

From what I saw on the news one end cap of the cylinder was gone, probably where the PRD was located. The rest of the cylinder looked fairly good.

By the way, I appreciate it if no one posted ways to cause a tank failure on this site. I'm sure that you can review past tank failures and figure out a way to create a life threatening condition all on your own.

[John Mitton]

On March 19, 2009 a step van converted to operate on natural gas by the California Linen Service was damaged by a cylinder explosion in Pasadena, California. The incident occurred while the van was being refueled at an onsite private refueling facility. The incident injured three people, all employees, one critically. One Type 4 cylinder from the van came to rest 200 feet from the van after the incident. The van and immediate surrounding area incurred significant damage.

CVEF is investigating the incident, which apparently involved the failure of two 14- year old type 4 CNG cylinders during fueling operations. The information available is preliminary and will be confirmed by CVEF’s investigation team led by John Lapetz Director of Technology. The team consists of John Dimmick and Rob Adams, contractors to CVEF who have assisted on NGV incident investigations over the last few years. They will make a site visit on Tuesday March 24th, accompanied by representatives of the National Highway Transportation Safety Administration (NHTSA), and will coordinate with SoCal Gas and California OSHA personnel. CVEF has received a number of reports and photos of the vehicle and cylinders involved and will make all of the information available as soon as the investigation is completed. As part of CVEF’s activities, we have compiled information on incidents since the 1980s, and have used this information to develop codes and standards to improve safety and reliability of NGVs, infrastructure and operations. If you have any questions or would like additional information, contact John Lapetz at the Clean Vehicle Education Foundation -- http://cleanvehicle.org/



{note our member afvman (http://www.cngchat.com/forum/member.php?u=1460) is also part of CleanVehicle.org -- you may want to contact him for more info}

[freedml]

The delivery truck fleet in Pasadena is a good test case for the kind of use that these tanks got -- fast filled 5 days per week year after year. The 15 year limit was calculated assuming this kind of daily use. If you're fast-filling your car every day, then I would be very concerned about replacing the tank when it expires. The relatively fast increase in pressure in the tank is a major stress on its structure.

Unfortunately, unlike some other types of high pressure tanks, there is no test to 'recertify' the type of CNG tanks found in passenger cars.

[cngacrossusa]

Any info that can be shared like how old were tanks, which manufacturer, etc??

Are plain old steel cng tanks (type 1) able to be Re-certified after 15 years with proper test, repainted, etc??

[afvman]

Greetings all,

Thanks to some great pictures from Cal Macy and conversations with CVEF, I'm more concerned about the vertical mounting of a cylinder inside the box, behind the drivers seat! Any cylinder, sitting on a metal ring even with a 'split rubber hose' for a cushion would be questionable! Constant bouncing up and down on the dome could eventually lead to failure of the best design construction.

This type of mounting would not meet today's NFPA-52 requirement for the cylinder and valve/PRD in the same compartment and although it may have been legal at the time, would be condsidered a safety hazard by current standards. More to follow, I'm sure, but for now, suspect that vertical mountings like this would not pass muster.

b/r,

afvman

[cngmike]

If any one would know the scoop it would be Cal. A friend of mine walked away from doing the maintenance on this station because of there safety standards. shortly after they had a fire at there compressors.

[cowboy]

I have been thinking again I have not read any reports of type 1 0r 2 tank failures just the plastic tanks have there been any catastophic failures of type 1 or 2 tanks used for cng as motor fuel ? also anyone got a guess as to how many cng tanks are in use for motor fuel in the us other than a lot?:)