Before I do something stupid...

[kidharris]

Originally Posted by Bon Voyage

I had a few propane vehicles 10 or 15 years back and they have tanks that either have an automatic shut off or when your filling you open a vent, when it gets to the 80% capacity it’ll start spraying out of the vent you know it’s full (80%) and you shut it off.

My old 2007 class A motorhome had the auto shut off, but anything with an auto shut off will have a vent also. My experience with my motorhome and pulling in to places to fill it led me to get the 20 lb tanks system like I put in my bus.

Yeah, my 200 gallon tank in the back yard is like that. Also, all (as far as I know) propane powered vehicles, including forklifts, are like that. Some even include fuel gages. What, I think you, and several others here are confusing is the difference between filling tanks meant to dispense liquids and those meant to dispense vapor.


High volume fuel use tanks, like vehicle and forklift tanks, have different valves and a tube that goes to the bottom of the tank to pickup liquid instead of vapor. This is to prevent the tank from freezing up and causing low pressure during high volume use. Vapor dispensing tanks do not have this liquid pickup tube going to the bottom. That's why the instructions tell you not to turn the bottle up side down or on it's side - then liquid in the tank may flow out the valve, no tube needed. Horizontal tanks/bottles have a slightly different setup because of the different liquid and vapor positions relative to the valve/outlet/pick-up tube.



" when your filling you open a vent, when it gets to the 80% capacity it’ll start spraying out of the vent you know it’s full (80%) and you shut it off"

I believe, not absolutely sure, that is liquid venting (not vapor?) which tells the operator filling the bottle that it is full, If a bottle only contains vapor, then it is too "empty" to be of much use, but it can still explode.

Automatic shut off when filling the bottle, don't know, never seen one. If there was one I would think that it would be in the propane cpmpanies gear.



Bottles/tanks do have an automatic high pressure pop-off valve (similar to the one required on your hot water heater) built into the valve to try to prevent an over pressure explosion when it gets too hot, but I don't think that is going to help you if the bottle gets crushed/flattened in a read-end collision situation. It cant vent fast enough and the gas it vents is going to be a fire problem.


BTW, a pop-off going off is scary, a lot of sudden noise and propane out. You definitely know something is wrong. Been there, done that.

My guess is that none of us here have enough knowledge to be designing propane systems. Personally, I would visit a large propane supplier and get some professional advice/opinions/knowledge.

[Zork]

Originally Posted by HamSkoolie

THANK YOU......

As someone who spent a career working with ordnance, safety, compressed tanks, etc. it amazes me how people think a propane tank is going to explode if it gets hit.....or shot. I have no idea how many "improvised explosive devices" (IED's) I've read about HERE IN THE STATES (not to mention YouTube vids with people upset that shooting a tank didn't do anything) that were made from a propane tank and shooting it. Here locally they even taped a flare to the tank and lit it before shooting it.
for a propane tank to cause an explosion when released into air there must be a concentration of propane that is between the upper and lower explosive limits (UEL LEL). Outside that window the mixture is too rich or too lean and will not combust. That window is 1.8 to 8.4 percent per the MSDS of propane manufacturer Airgas.

You can cause an explosion by exposing the tank to fire until pressure exceeds the capacity of the tank but there are pressure relief valves on tanks and that valve would also have to fail. Otherwise, all you'll get is more intense fire when the propane finds sufficient oxygen, which, inside an already burning fire, is usually in short supply.
Bottom line....... too many people rely on the concepts they've learned from Hollywood and ignorant politicians when it comes to explosions. NO gasoline cars do not explode at the bottom of the canyon, smoking while refueling a gasoline car isn't a guaranteed fire. And propane tanks ALMOST NEVER explode from fire or collision.
When does propane explode? When the pilot light goes out (old appliances), a fitting or valve leaks, or some other leak that is then contained but finds itself in the window between UEL and LEL AND THEN finds an ignition source.

You are far more likely to suffer a cold injury from a propane tank than a burn.
All that said, yes it can explode...... but it's not going to unless you walked under a ladder as a black cat crossed your path and when you jumped you knocked a mirror off the ladder.....

One of my most impressive demonstrations in classes has been when I light a cigarette and then put it out in an open container of gasoline.....then throw the still lighted match right in behind it!!!!!! This demonstration is usually done with a glass jar so that I can then ignite the gasoline VAPORS and demonstrate that the gasoline doesn't burn only the vapors (yes propane is already a vapor - keep reading) AND only at the point where the concentration of vapors is between the UEL and LEL which is some point just below the lid of the jar but above the liquid fuel.

END OF RANT BY ORDNANCE TECHNICIAN

Schooled by another jarhead. Imagine that.

[kidharris]

Originally Posted by Bon Voyage

Not sure if your question is for me but no I don’t want to lift it that’s why I went with 20 lb tanks.

Not sure but if you’re thinking it’ll explode, that’s not going to happen. For it to explode it would have to have oxygen with the propane inside the tank. If the tank were to get punctured it would spray out and if it then got ignited it might shoot out similar to a blow torch. Might be neat to see but not from the cab of a truck that hit it.

All you have to do is squeeze the tank to a smal lenough volume. Don't believe me? Stomp on or drive over a full beverage container/can/bottle. No fuel needed, it's an explosion caused by over pressure, but fuel and sparks (steel on steel, makes lots of sparks) certainly makes it worse.


A fuel explosion can happen outside of a tank....

https://www.youtube.com/watch?v=iC75dUjDIpo

This propane tank leaked, external ignition

https://www.youtube.com/watch?v=CUrRjxpJp9U

[kidharris]

Originally Posted by o1marc

My point was towards the comment of states that only allow filling by weight and not measure. I don't believe this is true.

Been over 20 years since I roofed in Texas, so I thought maybe the rules have changed, so I looked it up using this search term "propane law texas railroad commission" on DuckDuckGo

https://rrc.texas.gov/alternative-fu...m-gas-propane/

Followed a link to here

https://www.propane101.com/propanecylinderfilling.htm


took 2 whole minutes

[Zork]

Originally Posted by kidharris

A fuel explosion can happen outside of a tank....

This propane tank leaked, external ignition

The first video doesn't prove anything other than the typical clueless media conjecture. There is no evidence in the video to even support the title of the video.

The second one is, as you said, the result of a leaking tank, caused by negligence, which caused exactly what my fellow jarhead has been saying, that you need a mixture of fuel and oxygen. In other words, it supports his point. The tank itself did not explode, but the propane and oxygen in the car did.

[kidharris]

Originally Posted by kidharris

Automatic shut off when filling the bottle, don't know, never seen one. If there was one I would think that it would be in the propane cpmpanies gear.

Bon Voyage

YOU: "I had a few propane vehicles 10 or 15 years back and they have tanks that either have an automatic shut off"

ME: "Automatic shut off when filling the bottle, don't know, never seen one."

I got curious so I looked it up and you are right, newer tanks do have them.


One interesting thing about it is that it won't allow propane out of the bottle if it is not hooked up, so opening the valve while not hooked up will fool you into thinking the tank is empty. Worth reading.


https://www.propane101.com/opdcylindervalves.htm

[Oscar1]

Originally Posted by Zork

I agree, hence the current plan to put the tank inside a ventilated steel box... But anyway, IMO if rear end crashes were so much more common, there would be a lot more accidents involving propane and food trucks with tanks in the back. The actual number is tiny.

The number of food trucks on the road is not the metric you want to be using, a few food trucks moving only a few miles a few times a month compared to hundreds of thousands of rv’s traveling at interstate speeds all over the country, you’re not comparing apples and oranges here. And as previously said rear ended collisions would likely be way more common.

[kidharris]

Originally Posted by Zork

The first video doesn't prove anything other than the typical clueless media conjecture. There is no evidence in the video to even support the title of the video.

The second one is, as you said, the result of a leaking tank, caused by negligence, which caused exactly what my fellow jarhead has been saying, that you need a mixture of fuel and oxygen. In other words, it supports his point. The tank itself did not explode, but the propane and oxygen in the car did.

Sorry I still haven't watched the video. Had a whole 1/8 inch of rain and dust storm and the power went out. Odd watching dust devils and rain at the same time....anyways


the fire it self can deny some fuels the correct explosive or flammable range to combust (a primary cause of soot and visible smoke). This can change very suddenly (a gust or change of direction of the wind, opening a door or window, etc changing the available fuel to oxygen ratio).

For instance, incomplete combustion can cause a build up of carbon monoxide gas (a flammable, lighter than air, gas) which doesn't have enough oxygen available to burn or it is not in contact with the flame, but accumulates near the ceiling in structures or under a overhang. Something happens, some one opens the window, the roof caves in ..whatever...suddenly more oxygen or the flame jumps up a little higher...big fireball. I believe firefighters call this a flashback. It is not just Hollywood bs., it does happen in the real world, just not on cue.


Propane is heavier than air so it will accumulate on the ground along with CO2 and other heavier than air gases which can provide opportunities for this sudden explosive correction of the the propane to oxygen ratio required for its explosive or flammable range

https://www.engineeringtoolbox.com/e...its-d_423.html

As far as shooting propane tanks not exploding or catching fire, your just not doing it right.

My momma told me not to play with fire so I don't think you will catch me throwing lit matches at glasses of gasoline. The wind may change direction or the glass fall over. You also won't catch me following behind a vehicle with 100 pound propane tanks hanging off the back.

[kidharris]

Originally Posted by Zork

What is not a good idea for someone is not necessarily the same for others. I was once told it was not a good idea to join the military, that I should finish college among a gaggle of drunk kids who made drugs in chem lab and ran a prostitution ring from the girls dorm. I joined the Marines. Best decision I ever made. People who blow a gasket and have a shitfit when they run into others who don't think exactly like them should stay away from topics like this.

Well that explains it.

[HamSkoolie]

Originally Posted by kidharris

All you have to do is squeeze the tank to a smal lenough volume. Don't believe me? Stomp on or drive over a full beverage container/can/bottle. No fuel needed, it's an explosion caused by over pressure,...

Actually, that's not an explosion. While it is commonly, and improperly, referred to as such, an explosion is releases far more energy than what you described here. Perhaps you are confusing a Boiling Liquid Evaporative Vapor Explosion (BLEVE) with the miniscule stomping or quishing of a can/bottle?
To be an explosion there must be a significant pressure differential, not just a combustion process.

Originally Posted by kidharris

A fuel explosion can happen outside of a tank....

Actually, it can ONLY happen outside a tank unless one introduces oxygen or an oxidizer into the tank such as when building an IED. Inside the tank, even an empty tank, there is insufficient oxygen to support combustion. As an example, a vehicle fuel tank with a fire burning at the open filler neck is incapable of exploding no matter how long the flame burns. Seal the filler neck with the flame inside the tank and the oxygen is almost immediately consumed which extinguishes the flame, and again, no explosion.



Now to the two videos.
#1 shows a fuel air mixture igniting. It's combustion, but it is not an explosion. It's impressive, but an explosion would have produced a shockwave and at minimum caused serious and instantaneous mechanical damage to that building. It just started a fire.



#2 shows exactly what I described earlier when I said

"When does propane explode? When the pilot light goes out (old appliances), a fitting or valve leaks, or some other leak that is then contained but finds itself in the window between UEL and LEL AND THEN finds an ignition source."

The leaking BBQ tank (appliance) released flammable gas which was contained inside the vehicle (house) until it reached a level between the UEL and LEL and then found an ignition source (cigarette).
That video does not describe an accident but negligence. Propane (sold to consumers) within the UEL/LEL window is EASILY discernible by smell as a pungent odorizer is added so that it's presence is quickly known. The occupants were either ignorant of the proper transportation of propane or (more likely) ignored the danger.


EDITED TO ADD: WHAT? You posted videos to support an argument but you hadn't even watched the videos? JUST WOW

[Zork]

Originally Posted by Oscar1

The number of food trucks on the road is not the metric you want to be using, a few food trucks moving only a few miles a few times a month compared to hundreds of thousands of rv’s traveling at interstate speeds all over the country, you’re not comparing apples and oranges here. And as previously said rear ended collisions would likely be way more common.

Actually, it is exactly what I want to use because virtually all food trucks have their propane tanks in the rear.

[Zork]

Originally Posted by HamSkoolie

The leaking BBQ tank (appliance) released flammable gas which was contained inside the vehicle (house) until it reached a level between the UEL and LEL and then found an ignition source (cigarette).
That video does not describe an accident but negligence. Propane (sold to consumers) within the UEL/LEL window is EASILY discernible by smell as a pungent odorizer is added so that it's presence is quickly known. The occupants were either ignorant of the proper transportation of propane or (more likely) ignored the danger.

Otherwise known as "You can't fix stupid."

[CoffeeGuy]

Originally Posted by Contra Line Bus

Try using forklift tanks. They can mount horizontally.

I think there is a big difference between forklift tanks and the propane tanks used for cooking and heat. The forklift tanks feed liquid propane to the engine, where the BBQ style tanks feed vapor. These applications are not interchangeable, so I don't think the forklift fuel tanks will work in this application.

[Zork]

Originally Posted by CoffeeGuy

I think there is a big difference between forklift tanks and the propane tanks used for cooking and heat. The forklift tanks feed liquid propane to the engine, where the BBQ style tanks feed vapor. These applications are not interchangeable, so I don't think the forklift fuel tanks will work in this application.

I was just reading about that. So much for that idea.

[HamSkoolie]

Originally Posted by CoffeeGuy

I think there is a big difference between forklift tanks and the propane tanks used for cooking and heat. The forklift tanks feed liquid propane to the engine, where the BBQ style tanks feed vapor. These applications are not interchangeable, so I don't think the forklift fuel tanks will work in this application.

Not positive but having used and filled (myself) both, I believe the difference is ONLY EXTERNAL to the tank and nothing else. Just a matter of where the regulator is. The forklift doesn't use liquid fuel in the engines cylinders, it's metered in as a gas. Never worked on those systems but liquid fuel in a cylinder is a really bad thing. Filling the tank on the forklifts I drove involved the same exact process as filling a BBQ tank except that the tank was mounted on my forklift and filled in the horizontal position.

[Zork]

Originally Posted by HamSkoolie

Not positive but having used and filled (myself) both, I believe the difference is ONLY EXTERNAL to the tank and nothing else.

No, it is an internal difference. Forklift tanks have dip tubes which bring LIQUID fuel to the engine, not vapor like for a BBQ. You can get CO2 tanks like that too, I have one that I use to refill my SodaStream cartridges with liquid CO2 instead of gas. I have another tank without the dip tube that I use for homebrew beer carbonation.

[kidharris]

Originally Posted by HamSkoolie

Not positive but having used and filled (myself) both, I believe the difference is ONLY EXTERNAL to the tank and nothing else. Just a matter of where the regulator is. The forklift doesn't use liquid fuel in the engines cylinders, it's metered in as a gas. Never worked on those systems but liquid fuel in a cylinder is a really bad thing. Filling the tank on the forklifts I drove involved the same exact process as filling a BBQ tank except that the tank was mounted on my forklift and filled in the horizontal position.

You are right in the fact that the forklift engine does not use liquid fuel in the engine, however no one said that it did. After the liquid leaves the tank it acts very similar to a gasoline engine (which also does not use liquid fuel in the engine despite the fact that liquid fuel is pumped to the engine from the fuel tank).


You are wrong about everything else, the LPG vaporizes on the way to the engine. If you actually "used and filled (myself) both" as opposed to just changing tanks, then the training required to perform that task should have clued you. Even just changing tanks should have clued you that there was liquid coming from the tank.

[Oscar1]

Originally Posted by Zork

Actually, it is exactly what I want to use because virtually all food trucks have their propane tanks in the rear.

Are you building a food truck?

[o1marc]

Originally Posted by CoffeeGuy

I think there is a big difference between forklift tanks and the propane tanks used for cooking and heat. The forklift tanks feed liquid propane to the engine, where the BBQ style tanks feed vapor. These applications are not interchangeable, so I don't think the forklift fuel tanks will work in this application.

Propane can be used as a gas or a liquid. Depends on where the pickup in the tank is, tank can only be mounted in one for it's intended use. The tanks can be either, depending on the pick up tube.

[kidharris]

Originally Posted by Oscar1

Are you building a food truck?

LOL