Safely transporting propane

[slomatt]

I've always felt that the 16oz green cylinders are an inelegant way to transport propane, mainly because they have a small capacity and cannot legally be refilled. A 1 gallon (4.5lb) re-fillable tank seems to be a great solution, but I'm a bit concerned about transportation.

These types of tanks are designed to vent if the internal pressure exceeds ~375psi, which would lead to the release of gaseous propane into the surrounding space. Because of this many states have laws prohibiting the transfer of propane tanks in the passenger compartment.

http://fm.colorado.edu/firesafety/PropaneGasTransporation.html
http://msucares.com/news/print/fcenews/fce02/020916.html

This is not a big deal for trucks or cars since the tank can be stored in the bed or trunk respectively, but for those of us with SUVs this is a problem. And I can't think of any alternative locations. I would hesitate to put a pressurized vessel outside of the vehicle for fear of puncture or collision.

The only possible solution seems to be to build an air-tight storage compartment inside the vehicle that vents to the outside. This could possibly be integrated into a rear storage platform, but getting a good seal and vent could be problematic.

Anybody have thoughts on transporting propane in tanks? I would hope that the risk of venting is lessened by the new pressure-control fill valves, but it's still going to vent if the temperature gets high enough.

 

[LaOutbackTrail]

I'm not very familiar with propane tanks, but, where does it vent from? Is there any sort of hole where you could put a hose over and simply run the hose out of the vehicle? I'm thinking that might be the easiest option if it is at all possible.

 

[Grim Reaper]

Just need to have an open vent to the outside. Slide in campers and some smaller campers do it all the time. For that matter a car battery vents Hydrogen. It also need to be vented to the outside.

Personally I'd throw a propane tank that small on the roof rack.

I hat the little tanks as well and when pulling my little trailer I will have a 20lb tank and only keep 1-2 of the little tanks as a back up.

 

[Green Ganesha]

I originally carried my propane on the roof rack. I cut circles out of plywood the same diameter as the base of 25# tanks, mounted the plywood to my rack with U-bolts, and secured the tanks with ratcheting tie-downs through eyebolts. (Since then, I've relocated propane storage to a trailer.)

 

[ntsqd]

FWIW, though still inelegant there are small propane tanks available that are legally refillable.

What about under the SUV? Either of my 4x's would swallow a 1 lb tank whole.

From what I can tell the venting method is a disc designed to rupture at the present maximum pressure. Pretty SOP for this sort of thing, but that means that the venting is sudden rather than gradual. The venting ports in this sort of contraption are usually 90* to the axis of the cylindrical body of the safety device in order to try to dissipate the blast. Clamping a hose over it would likely be problematic.

 

[BigAl]

IIRC the 25lb tanks fit perfectly into a milk crate which gives you some more mounting options.

 

[overlander]

Here's the model I'm working off of for my 110. I'm going to have a rack like this built for a 10 lb tank that I saw at Northern Tool. There is also a 5lb tank as well.

 

[rusty_tlc]

I believe the pressure relief valves on propane tanks are the POP-Off type ie they will open just long enough to reduce the internal pressure to within safety limits then close.

I ran across this while I was looking for a info on this topic and thought it worth posting to this discussion;

A safety note for you: Propane cylinders of the DoT design must be transported and stored in an upright position so the pressure relief device will function properly. Laying the cylinder on its side in the trunk of your car is a potentially very dangerous situation.

 

[ntsqd]

Interesting. My inspection didn't lead me to think that they were of that type, but that is what I would expect them to be.

 

[MountainBiker]

I believe the pressure relief valves on propane tanks are the POP-Off type ie they will open just long enough to reduce the internal pressure to within safety limits then close.

Quote:
A safety note for you: Propane cylinders of the DoT design must be transported and stored in an upright position so the pressure relief device will function properly. Laying the cylinder on its side in the trunk of your car is a potentially very dangerous situation.

I ran across this while I was looking for a info on this topic and thought it worth posting to this discussion;

True! But there are some tanks designed for transport on their side, because some travel trailers require them to be stored that way for clearance.

 

[kellymoe]

Here's the model I'm working off of for my 110. I'm going to have a rack like this built for a 10 lb tank that I saw at Northern Tool. There is also a 5lb tank as well.

I have that rack on the back of my 130. It came with two 10lb tanks but unfortunately they are euro spec and dont mesh with stuff sold in the US. I didn't know about the Northern Tool bottles. I'll take a look.

 

[rusty_tlc]

Interesting. My inspection didn't lead me to think that they were of that type, but that is what I would expect them to be.

I've had freshly filled tanks vent a little when they sat in the sun to long.

 

[rusty_tlc]

True! But there are some tanks designed for transport on their side, because some travel trailers require them to be stored that way for clearance.

I've only seen that on motor homes and then the valve is located on top. I'm assuming upright means with the valve on top with out respect to the shape of the tank. This makes sense. If the over pressure valve were below the vapor level an over pressure tank would vent liquid propane. One of the rocket scientist here would probably know how much more liquid would need to be vented to reduce pressure compared to vapor. But I'd think it would be somewhere between a butt load and bookoo bunches.

 

[slomatt]

It's sounding like there is no good option for propane storage in an SUV. Since the tank has to be mounted vertically it would be very difficult to fit it under the truck, and on the roof I'd be worried about exposure, wind resistance, and the chance of it hitting a low-hanging tree branch. It seems that the only viable option (in my opinion) would be to mount it on the rear of the truck but then I'd worry about being hit by another vehicle. This is a bummer since I would really like to move away from disposable tanks.

Does anybody know if the 16oz green cylinders are also designed to vent off excess pressure? Most of us have driven around with them many times with no problems.

Oh, and as a side note. Most places online seem to have the 1 gallon tanks for ~$55, but yesterday I ran across a 1 gallon tank for $35 at Orchard Supply Hardware.

- Matt

 

[mk4]

I've traveled with mine for a while without any problems.

Your cylinder should come with an OPD (overflow prevention device) valve. When the pressure is XXX psi (or 80% full), the tank will relieve itself. When it does, you will know. The valve is on or off, not 10% open or 50% open, it's either open or closed. So unless you're getting your tanks filled or have them stored in some really hot environment, I wouldn't worry.

Propane also has added odor, so when there is a leak, you'll be able to smell it.

Another reason why propane should be stored upright is to prevent accidents. If you shear the valve while in an upright position, the tank will be supported by the floor. If you shear the valve while laying on its side, you will now have a projectile.