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Thousands Of LPG Vehicle Gas Tanks Dangerous


george

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Are you sitting on a bomb?

Thousands of substandard vehicle gas tanks are at the centre of new explosion fears.

BANGKOK: -- Drivers of natural-gas powered vehicles should beware substandard tanks and conversions can explode, injuring you and others.

An expert says while there are hundreds of mechanics skilled in installing tanks and conversion systems, there's nobody to check that work and declare it safe.

Graduate School of Energy and Environment specialist Athikom Bangvivat says there are 138 liquid-petroleum gas installation centres certified by the Land Transportation Department.

But, there's just 49 inspectors to monitor all these centres. There are zero qualified specialists checking on the standards of gas tanks used in converted vehicles.

"No one can guarantee gas tanks will not explode," he says.

With soaring petrol prices as a result of high crude futures, the government is encouraging motorists to convert their cars to run on natural gas.

It's believed there are 93,500 vehicles on Thailand's roads burning natural or liquid petroleum gas.

But, because of the lack of monitoring, people are getting worried there will soon be a bad accident.

Lerdsin Hospital director Dr Pravit Limkuansuwan is frightened drivers, passengers and others are at risk of serious injury caused by an exploding gas tank or substandard installation.

He says illegally installed gas-fuel systems or improper installation cannot handle the high pressures required.

Gas is stored at 3,000 pounds-per-square-inch. If gas under this much pressure explodes, it can cause serious injury. These can include middle ear and other nasty internal injuries.

As well as flying metal, injuries occur because of the massive pressure exerted on the body in such an explosion.

However, PTT marketing vice president Punnachai Footrakul says the gas tanks used here are up to international standard. Installations are carried out to exacting world standards, too.

PTT and the Defence Ministry have tested tanks by firing bullets at them, setting them on fire and putting them under extreme pressure.

None have exploded.

-- The nation/Xpress 2008-08-07

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Interesting...I thought that LPG was stored at about 105psi (7.5Bar) and NGV is stored at about the ststed pressure. If I remember correctly our LPG tank, installed so two years no, was 3/8 thick...guess I'll go and check again at his shop. For those of you really interested see http://www.sae.org/technical/papers/2006-01-1274.

So is this article about LPG or NVG.

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Not to mention this

Warning its a bit graphic!!

http://www.gasexpertthai.com/index.php?pag...n=view&id=6

Guy tries to fill LPG tank with NGV..... bye bye. I think we are going to see a few more of these as well. This was a Volvo imagine what would happen to the Japanese tin cans... But isn't regulation another word for bribery in LOS?

oz

Edited by ozsamurai
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Not to mention this

Warning its a bit graphic!!

http://www.gasexpertthai.com/index.php?pag...n=view&id=6

Guy tries to fill LPG tank with NGV..... bye bye. I think we are going to see a few more of these as well. This was a Volvo imagine what would happen to the Japanese tin cans... But isn't regulation another word for bribery in LOS?

oz

sure is a bit graphic :o

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I understand that the NGV tank's storage pressure is much higher than required for the LPG system.

I'm sure that the tanks (NGV & LPG) are manufactured to a high standard and you can shoot them, involve them in traffic accidents and hit them with golf 'sticks' without risking them 'exploding'. However.....

...the 'engineer' fitting the pipes together that link the tank to the car's fuel system is the weakest link in the vehicle's safety chain. It's there the risk of a future leak is created, and this is true for LPG, NGV and old fashioned gas gas (benzine/petrol/etc.)

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...no vehicles in Thailand are ever inspected for safety the odds...
I was just about to say that the safety inspection is when the vehicle is 7 years old, however as many older cars are the exact ones that are NGV converted - I think my old tin hat and body armour will be required should I get one in the future. Omg - taxis!
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Since no vehicles in Thailand are ever inspected for safety the odds of being killed by an overloaded vehicle, blown tire, bad brakes, no lights, etc. are far more likely.

Incorrect.

Vehicles older than 5 years are inspected every year at road tax renewal time.

Of course that does not mean that your concerns are not valid ones.

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There is a very real danger from the LPG Tanks installed in Tuk Tuks, they are mounted just under the passenger seat and at a height which would make them the first point of contact if the vehicle was "rear-ended".

Additionally many of these Tanks are second hand - imported from places like Japan where there are regulations that LPG Tanks on all vehicles must be changed every few years. They ship the old ones here.

Patrick

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The good news is that cooking gas bottles, periodically, as they are sent back for refilling get hydrotested. Something like once per year.

If these people are so concerned they should lobby for a law requiring a hydrotest for vehicle cylinders.

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...no vehicles in Thailand are ever inspected for safety the odds...
I was just about to say that the safety inspection is when the vehicle is 7 years old, however as many older cars are the exact ones that are NGV converted - I think my old tin hat and body armour will be required should I get one in the future. Omg - taxis!

Incorrect.

Vehicles older than 5 years are inspected every year at road tax renewal time.

Of course that does not mean that your concerns are not valid ones.

Ah! I stand corrected then. I have had 3 "safety inspections" so far on 3 different trucks, and as far as I could tell they each consisted of checking the engine and body numbers! A bit off topic but I would be curious to know if anyone who has had a "thorough" one could briefly describe it...

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The good news is that cooking gas bottles, periodically, as they are sent back for refilling get hydrotested. Something like once per year.

If these people are so concerned they should lobby for a law requiring a hydrotest for vehicle cylinders.

Out of curiosity I checked the 3 15 kg gas bottles we have at the house right now:

#1 tested in 1990 and retested (per stamping) 2005

#2 tested in 1997 and retested in 2002

#3 tested in 1987 and never retested!

Like most laws here, enforcement appears to be rather scant...

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The good news is that cooking gas bottles, periodically, as they are sent back for refilling get hydrotested. Something like once per year.

If these people are so concerned they should lobby for a law requiring a hydrotest for vehicle cylinders.

Oh no their not....possibly required by "law"....but not done...

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"Gas is stored at 3,000 pounds-per-square-inch.."

"However, PTT marketing vice president Punnachai Footrakul says the gas tanks used here are up to international standard. Installations are carried out to exacting world standards, too"

Typically cylinders like these would be designed,constructed and inspected to an international standard like ASME section VIII, BS EN 5500 - unfired pressure vessels and stamped up as such by a certifed inspector...I can assure you the ones I have looked at out of curosity, dont appear to be marked/stamped up with anything I recognise as a design/construction code, and I am actually in the business of pressure vessels....

At 3000psi....you are sitting on a bomb, irrespective of how its built/designed or inspected.....personally, I would never have something like this installed in boot of my car, however high the fuel prices get

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At 3000psi....you are sitting on a bomb, irrespective of how its built/designed or inspected.....personally, I would never have something like this installed

That is a standard pressure for scuba diving tanks. On each boat there are about fifty of them and they get refilled by "engineers" about four times a day and they serve for many many years, and people wear them on their backs underwater for many many hours.

LPG, by contrast, is stored at 30 times less pressure than either NGV or scuba tanks.

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At 3000psi....you are sitting on a bomb, irrespective of how its built/designed or inspected.....personally, I would never have something like this installed

That is a standard pressure for scuba diving tanks. On each boat there are about fifty of them and they get refilled by "engineers" about four times a day and they serve for many many years, and people wear them on their backs underwater for many many hours.

LPG, by contrast, is stored at 30 times less pressure than either NGV or scuba tanks.

The issue, without getting too technical is not just the pressure per se, its to do with the volumes and surface area of the tank, the unit we are measuring in is pounds per square inch(or Kpa)...therfore for evey square inch of the internal surface area of the vessel we will have 3000 pounds of pressure acting on it..the bigger the surface area of the tank or vessel, the higher the loads or forces involved for any given pressure

....the internal surface area of a scuba tank is quite a lot less than the internal surface area of the "tanks" used for LPG pr NGV, also have to consider the contents of the tank or vessel, we are playing with here--- highly flammable liquids and gas....not air.....in fact the failure of a large diameter pressure vessel at "low pressure" is will be more catastrophic than the failure of a small diameter vessel at "high pressure"

Also another point of operating a vessel at 3000psi (or any pressure for that matter) is to do with pressure relief if something goes wrong, ie a tank or vessel in the boot of a car is subjected to heating from the sun etc, increasing the pressure and there has to be a way to relieve the pressure from the tank to stop it exploding from over pressure, typically something called a PSV is used, these have to be serviced and checked periodically to make sure they work.....over pressure from external heating on a scuba tank would not really be an issue, seeing as you are in the water...

So there a lot of factors to consider when assessing the risk of using a vessel/tank, using a scuba tank, the inherent risk is a lot lower than a LPG or NGV tank when considering the service, contents and lack of maintenance and inspection.

Its interesting to note a comment by another poster which says I believe in Japan, tanks in need to be replaced every few years....makes you think that the Japanese are on to something as regards the risk of failure...

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Oh good...more fuel for the scare-mongers

Dont think its a case of scare-mongering, IF the systems are designed, constructed and maintained correctly, you should not get any "big bangs" in the car..... but certainly the inherent risk is higher using LPG or NVG in the boot of your car over conventional fuels...

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Oh good...more fuel for the scare-mongers
Yes but it's cheaper fuel so they can whine longer for less Baht - and there's the enviroment as well :o

I think the issue about pressurized gas tanks is a blind - its the connecting pipes that link to what I assume is a pressure regulator that would worry me, and probably will next time I smell something odd (?) in a taxi.

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Oh good...more fuel for the scare-mongers
Yes but it's cheaper fuel so they can whine longer for less Baht - and there's the enviroment as well :o

I think the issue about pressurized gas tanks is a blind - its the connecting pipes that link to what I assume is a pressure regulator that would worry me, and probably will next time I smell something odd (?) in a taxi.

Cuban, would agree with you regarding the interconnecting piping, you have to consider the whole system when looking for the possible "big bang"......the next time you smell something odd in the taxi make sure its not the driver having a "tot" before worrying about the tank in the boot... :D

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There is a very real danger from the LPG Tanks installed in Tuk Tuks, they are mounted just under the passenger seat and at a height which would make them the first point of contact if the vehicle was "rear-ended".

Additionally many of these Tanks are second hand - imported from places like Japan where there are regulations that LPG Tanks on all vehicles must be changed every few years. They ship the old ones here.

Patrick

Given that LPG powered tuk tuks have been prevalent in thailand for many years, why is it we haven't heard of any exploding? ...upon impact or otherwise?

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There is a very real danger from the LPG Tanks installed in Tuk Tuks, they are mounted just under the passenger seat and at a height which would make them the first point of contact if the vehicle was "rear-ended".

Additionally many of these Tanks are second hand - imported from places like Japan where there are regulations that LPG Tanks on all vehicles must be changed every few years. They ship the old ones here.

Patrick

Given that LPG powered tuk tuks have been prevalent in thailand for many years, why is it we haven't heard of any exploding? ...upon impact or otherwise?

It wouldnt be a case of explosion per se would be leak and possible fire...

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ozSamari: Guy tries to fill LPG tank with NGV..... bye bye. I think we are going to see a few more of these as well. This was a Volvo imagine what would happen to the Japanese tin cans... But isn't regulation another word for bribery in LOS?

Surely they have a different nozzle for attachment? I am not familiar with NG but would assume the standard LPG nozzle would fail under the immense pressure of transferring fuel from the storage to the vehicle tank.

The graphic images in the link from the OP show a gas tank that is barely damaged from the explosion. The possibility of a fitting or gas line failing is highly probable.

Caution: Any concerned TV members should be vigilant to unusual smells in or around their vehicle. Any suspicion that LPG is leaking should prompt a rapid call to the fire brigade and the evacuation of everyone within 50 metres. People may think your being silly. But if the vehicle explodes they will thank you! If confirmed as a definite leak, make it 100 metres +

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Since no vehicles in Thailand are ever inspected for safety the odds of being killed by an overloaded vehicle, blown tire, bad brakes, no lights, etc. are far more likely.

Incorrect.

Vehicles older than 5 years are inspected every year at road tax renewal time.

Of course that does not mean that your concerns are not valid ones.

Seeing the amount of rust buckets around, vehicles spewing black smoke etc, could one dare to assume that these checks are somewhat less than that stringent?

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