Thousands Of LPG Vehicle Gas Tanks Dangerous

[Plus]

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"

They are not that different in size.

Most of the time scuba tanks are NOT in the water, and it's not unusual for a filled tank to stand unused in the sun for a whole day. They just don't blow, and the piping and stuff work like a swiss clock. Of course oxygen wouldn't catch fire like NGV or LPG, but the pressure itself is not a problem.

Every kitchen in this country of 66 million has an LPG "tank". That's an awful lot of tanks that never ever blow up or leak or catch fire. In case the escaping gas does catch fire, you can just turn it off, it won't blow - I've seen a demonstration, though it would be difficult to turn off the flaming gas in the car, of course.

Where have you been with these safety concerns when people were advocating using cooking gas cylinders in motorcycles? There's a thread about it somewhere in "general". Looks like I've been caught between two extremes.

[Soutpeel]

Going to cite the recent problem with a hole blown in Quantas jet, its suspected that an oxygen cylinder exploded in the belly of the plane, blowing a big hole in the side of the jet, these oxygen cylinders are somewhat like scuba tanks...if this incident had gone a different way...a "scuba" tank could have been responsible for a couple of hundred deaths..

[Plus]

Do you mean to say that scuba diving is dangerous because tanks might explode like on that Quantas jet?

I'm not saying that there's no danger in running cars on LPG or NGV but that it's seriously blown out of proportion. They only need to make sure proper installation procedures are followed. Inherent dangers with tanks is not the problem here - the problem is the lack of management and control. Or, in other words - if they want to make LPG/NGV safer, thery should start not from tanks but from their certification process.

[Soutpeel]

Do you mean to say that scuba diving is dangerous because tanks might explode like on that Quantas jet?

I'm not saying that there's no danger in running cars on LPG or NGV but that it's seriously blown out of proportion. They only need to make sure proper installation procedures are followed. Inherent dangers with tanks is not the problem here - the problem is the lack of management and control. Or, in other words - if they want to make LPG/NGV safer, thery should start not from tanks but from their certification process.

First thing is the Quantas jet didn't "explode"....its suspected an oxygen cylinder inside the jet exploded, the investigation is still on-going as to the actual cause, the reason I mentioned this incident is that it illustrates that tanks/vessels etc can and do explode in a given set of circumstances...am I suggesting that all tanks/vessels under pressure will explode..No....In diving there is a bigger inherent risk of drowning, than being blown up by your scuba tank, but can we also say there is absolutely no chance of a scuba tank exploding in a given set of circumstances..No we cant say that...is the risk pretty low, yes it is..

I dont believe the issues around the LPG/NGV systems are being blown out of proportion, as I have spent nearly 20 years in O&G, refineries etc looking at the likelyhood and consequences of when systems containing hazardeous/flammable chemicals under pressure decide to go "bang".

Industries worldwide spend millions of $ a year, maintaining/inspecting systems so they dont go "bang"...granted the tanks and vessels are a lot bigger, but contain chemicals etc which are no more dangerous than what is in the LPG/NGV cylinder in the back of your car.

The major issue I have with the whole LPG/NGV situation is that these systems are being retro-fitted in vehicles which where not structurally designed for LPG/NGV by the vehicle manufacturer.

Should someone like Toyota sell a vehicles for specific LPG/NGV use, ie the system is factory fitted would have a bit more confidence, but at the moment seems to be that installations/maintainance is being carried by people who are possibly not "qualified" etc etc.

My prediction would be as more and more conversions are being done, we will start seeing more incidents relating to LPG/NGV use in vehicles.....I use the word incident as opposed to explosion..as to me fire is the biggest risk

[ataloss]

...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...

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

Hmmm...this truck seems to have slipped through the inspection net...scary:

http://www.thaivisa.com/forum/Tilting-Vehicle-t204778.html

[byronvandamme]

I like the way so much fervour is created by this story.

Most of us living here in Thailand either eat at restaurants or street stalls or at the very least walk past them on a daily basis.

If these places are explosion proof then forgive me for diverting the subject as what do I know.

[Cuban]

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...

Well I think we should be told! What is the calarific value of ¹/₂ a litre (STP) of human methane 2 hours after a Som Tom salad with extra Plar Rar? What is the risk of exact stoichiometric balance of air to such Thai food 'gas' in a taxi after a 120 Km journey?

More seriously - LPG in the home: The tanks and pipe work is not bouncing around the roads during the day - and generally all tanks are stored outside the house, allowing any leakage of LPG gas to disperse. In a car the boot is an enclosed space allowing any leaked gas to build up and then be ignited by any of the normal suspects. Not sure static would be a big problem here, air too humid?

Again tuk tuks and the mobile hot food stalls are open affairs where any leaked gas will blow away, and I would expect the operator to beware of any leaks as they run on tight margins so lost gas is lost profit. Also short pipes that are easily fixed with a knife and a screwdriver. The average motorist, and I see this morning a bus driver, is isolated from the workings of the gas system installed in their vehicle. For service vehicles that are not owner/operated the driver will have little interest in the support of the vehicle - you see this when they have an accident and run away! (Somebody else's problem.)

Normal benzine gas/petrol can be seen leaking so would be picked up more quickly (I guess), The normal fuel tank and the pipework connecting it to the engine is outside the body of the vehicle - NVG/LPG tanks are mounted inside the vehicle - I think this is the crux of the problem.

If I were considering a gas converstion of this nature I think I would look at externally mounted tanks and piping.

Look at the big trucks with NGV tanks you see on the highways - I have not heard of them blowing up - tanks mounted outside the body of the vehicle.

Is the cure this simple? (You heard it here first.)

[cloudhopper]

One other point to consider - CNG is methane and is lighter than air so any leaked gas will rise and normally dissipate quickly. LPG is a mix of propane and butane and is heavier than air so leaked gas can pool like a liquid and will explode if ignited.

[Tony Clifton]

Nothing wrong here, same as trying to find a real plumber or l<electrician in there parts. Everyone improvises.

The number of vehicles using it is way too low. There was good footage on tv of strange contrptions made for mcycles, boats and pretty well anything that needs fuel. My wife talked of converting a brand new diesel truck. Nope because of the contant botched jobs and no because of market manipulation.

[kartman]

Sorry have to ask, Did the next customer at the ServiceStation ask "Can anybody give me a hand to fill up ???"

[Tony Clifton]

One thing they have to work on is the storage of dozens if not hundreds of tanks of LPG by individuals doing business in residential areas.

There 's one a hundred yards away, and it seems every moo ban in the area has one.

Disaster waiting to happen.

[alexisthetiny]

The article in the original post is a little confusing. Are they referring to LPG or CNG? There's a pretty big difference. Anyway, I'll tip in my two cents since I'm in the CNG business. Tanks for LPG and CNG are vastly different. LPG is stored in pressurized steel cylinders. CNG is stored in steel cylinders as well but owing to the fact that it is compressed to 3000psi, the cylinders and the parts of conversion kits are made to be able to withstand the pressure of CNG. CNG cylinders are made from one piece of steel so there aren't any welding seams that would become weak points in the cylinder. CNG cylinders are required at the very least to go through a bonfire test and ballistics test, these are to make sure that under fire conditions or in case of a rupture, the tanks do not explode. Also, some cylinders come with safety functions in the cylinder valves that will automatically release the CNG if the pressure in the tank become abnormally high to prevent an explosion. Since CNG is mostly methane, its lighter than air and will rapidly dissipate, maybe it'll stink up the car a little since the regulations require that CNG be 'flavored' with the 'scent' of either rotting cabbages or rotting eggs to warn people of its presence. Anecdotally, my company in Singapore has had a customer whose converted vehicle was hit from the behind in an accident and the cylinder held up to the impact remaining unscathed while the rest of the car was pretty wrecked. I have the pictures somewhere.

Also, in terms of flammability, CNG is a lot safer than LPG as CNG requires specific conditions for ignition. Firstly, there needs to be the right ratio of CNG to air. Generally this would be about 5-15% CNG in the air. AND it requires a temperature of 600 degrees Celsius. Unless these two conditions are fulfilled, CNG would not ignite. And CNG would never pool like liquid fuels would.

Additionally, when a garage converts a vehicle to CNG, they will need to apply for a PTT certification that states that the vehicle meets certain safety standards. Once this certification is gotten, the vehicle owner will be issued a gold card and only with it can they pump CNG at gas stations. However, this rule is not always enforced. In Chiangmai, yes, in other parts of Thailand, I'm not too sure.

Ultimately, the most important thing is to exercise common sense and caution. Pick a reputable garage to do a conversion, ask lots of questions and if in doubt, there's always Google. So far, the reports of CNG explosions I've come across in Thailand are those where slightly dubious practices are suspected or like when someone installed a carbon fiber wrapped cylinder and then PEELED the wrap off the cylinder.

Ok, I'll get off my soap box now. =)

[Bard]

The most dangerous is the LPG, if it leaks from a parked car and someone start there nearby... Anyone seen the fuel bomb used in a lot of wars? You get the idea. You get the same effect as a fuel bomb from LPG, whilas CNG as previously stated is lighter than air lifts to the atmosphere, so it is far safer but still a 3000 psi highly flammable gas cylinder in my trunk, a crash from the rear from a Hino and it will fail, any sparks (likely) will not make it better.

That is why in the separate room I store my cooking gas bottles I have LEL sensor mounted at floor level and will shut in the gas, start a EX proof blower to ventilate the room plus sound fire alarm in my house at a level which still is safe, but I have shutin the problem, venting it out safely and got out of the house before it becomes a real danger. A perfectly good alternative is to have them in a well ventet locker outside of your house, and use a magnet valve to open it into your house only when you need it.

I would never install any of those systems in my cars, no way. I don't care for the price of fuel compared to my family and my own life, it is more worth than that. Easy fixes if fuel is expensive and you feel it's to much is, drive less, don't drive in 80 - 100 mph but 55 mph, change in your car for a fuel efficient one, smaller or whatever. A small fuel efficient car uses 5 litres or less per 100 kilometres, so you need to drive a lot for it to make any economical sense at all... And can I walk there? Use a bicycle? scooter?

[NanaFoods]

CNG as previously stated is lighter than air lifts to the atmosphere, so it is far safer

This might be true in the West.

But this is false in Thailand, where ignorance meets cheapness. Because of this cheapness, no Thai is going to put up with his hard-earned baht leaking out of his tank overnight. Those kinds of problems tend to get fixed ASAP.

The problem it seems is cheap-charlie morons using LPG tanks to fill with CNG.

LPG has been used for cooking all over Thailand for a long time and has been in tuktuks and taxis for quite some time as well - nary an explosion reported.

Since CNG came to the scene, its been "boom-boom out go the lights".

[jts-khorat]

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.

Took exactly THB 50 more than the usual fee (THb 150) to have the mechanic 'hurry' and just put a signature on paper, as lunch break was starting and neither he nor me wanted to wait until afterwards.

[kenk3z]

It turns out you can get something of a performance boost on a diesel engine by injecting a little LPG into the airstream going into the intake manifold. So you have kids here in the States with cooking (barbeque) tanks sitting on the passenger floor space in order to get a little extra performance. Hopefully common sense takes hold and the kid trades in the diesel for a gasolene car.

Are the taxi conversions in Bangkok typically LPG or CNG? That isn't clear to me. I rode in something that had been converted and you're out of luck if you have any luggage, the tank takes up just about the whole Corolla trunk.

Aren't the fill fittings totally different?

kenk3z

[Gary A]

By far the most dangerous thing I see is that thousands of people don't know the difference between CNG and LPG. CNG is a fairly recent thing and due to the extremely high pressures required for storage, it is far more dangerous than the relatively low pressure LPG.

A good example is the oxygen cylinder that recently blew a huge hole in the side of an airliner.

[ratcatcher]

It turns out you can get something of a performance boost on a diesel engine by injecting a little LPG into the airstream going into the intake manifold. So you have kids here in the States with cooking (barbeque) tanks sitting on the passenger floor space in order to get a little extra performance. Hopefully common sense takes hold and the kid trades in the diesel for a gasolene car.

Are the taxi conversions in Bangkok typically LPG or CNG? That isn't clear to me. I rode in something that had been converted and you're out of luck if you have any luggage, the tank takes up just about the whole Corolla trunk.

Aren't the fill fittings totally different?

kenk3z

I don't know the exact ratio, but vast numbers of taxis run on LPG , maybe its 60%-40% CNG - LPG?

A proper installation done by a certified, registered shop, then inspected at the Land Transportation Department should prove trouble free.

Back alley shysters doing conversions for B8000 are the danger. You get what you pay for. Trouble is other people can lose their lives due to their stupidity.

I agree that the taxis are inadequate for carrying luggage, at least more than one suitcase. Trunk space with tank is very limited.

[madjbs]

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

That looks very much like an ngv tank to me. Anyhow, I'm pretty sure it's not possible to fill the tank with the wrong gas as the connectors on the pumps are different.

[kartman]

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

That looks very much like an ngv tank to me. Anyhow, I'm pretty sure it's not possible to fill the tank with the wrong gas as the connectors on the pumps are different.

Is it "a" ngv tank i think maybe two tanks here in tandem, one in first car pics looks like lpg maybe and another wrecked one being inspected don't know. Is car a Volvo? i think maybe early Hyundai.

My senario here is- Guy has lpg conversion then decides to save more money and buy alloy wheels by changing connectors(why not TIT) and running on ngv - works but mileage is crap so fits another tank(who knows what) and eventually BOOM !. But at least his dependants still have a set of shiny alloys.

[monty]

My senario here is- Guy has lpg conversion then decides to save more money and buy alloy wheels by changing connectors(why not TIT) and running on ngv - works but mileage is crap so fits another tank(who knows what) and eventually BOOM !. But at least his dependants still have a set of shiny alloys.

No chance!

An LPG tank would explode the very first time you'd try to cram in CNG at 2000 PSI!

LPG is stored at maybe 120 PSI, and I doubt the tank will stand much over 600 or 700 PSI!

[kartman]

Maybe his last words were "this was my first time AAAARRRRGGGHHHH--------)???????????

[mdechgan]

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?

Tuk Tuks are made like tanks. These things are made of heavy gauge steel with stainless steel bars unlike are cheap aluminium jazzes and vioses