Forklift LP Tank

[David Tilston]

I have been considering changing the LP mount on my trailer to accept a forklift tank. The tank would lay down across the front of the trailer with the 2 x 6V batteries in front of it. The 33.5# aluminum tank costs $210 in Calgary.

Why?

Well mostly because I think it would look cool. Not very rational, so lets start rationalizing.
- I can fill the tank at a gas station and pay by the litre, (gallon).
- It has a fuel gauge
- They are available in aluminum, (polished to a mirror, cool!)... I mean light.
- Sizes are 20#, 33.5#, and 43.5#. I hope to support all three with one bracket.
- Can get a liquid, (propane electrical generator?) and vapour.
- Can be used to refill 1# cylinders.
Manchester Tank: 1# Refillable Cylinders
- Slightly smaller diameter combined with tucking it in under the slope of the front of my Trillium 4500 would provide a more compact install then two 20# bottles.

Please feel free to point out the error of my ways.

[BCDave]

Sounds like a good plan actually! the 43.5# would give you more "profane" storage than two- 20 pounders and with the gauge you'd not risk running out.

However, I'd want to be sure it is legal and acceptable by your insurance company (and the motor vehicle licensing folks, too!) , just in case.....

I do not know if the "standard" 20 and 30 (etc) pound bottles are "crash tested" or how they are rated for use on highway (and on your BBQ!) but the forklift ones may well be a whole 'nother creature. (but the idea of a having a Polish - er, ahem, I mean polished alum one is very appealing!)

[Greybeard]

In some case/places, it may be illegal to carry a propane tank in a horizontal position.
I think it has something to do with it being propelled if the head gets taken off accidently

[BCDave]

Originally Posted by Greybeard

In some case/places, it may be illegal to carry a propane tank in a horizontal position.
I think it has something to do with it being propelled if the head gets taken off accidently

I hadn't thought of that....

There are the stories - mostly "urban legends", (I suspect) of a train wreck where a propane tank car got its end crunched and then lit off, becoming a rocket-propelled device that traveled for a few miles at high speed, setting of forest fires in the process.......

Train car loads of the stuff aside, I can see how it would be more dangerous to have the valve end facing outwards instead of on top.....

[David Tilston]

Um...Propane is not at that high of a pressure. At -40 (F or C you pick) it can be carried in a bucket.
Thrust from combustion is ...um ... unlikely. This is rocket science after all.

Now a welding cylinder. Well, the shop video was really impressive!

It is DOT approved. What else could count? I don't think that they rate them by maximum allowable velocity. I'm no expert though.



I gotta tell you, they seem better built then the average BBQ tank.

[Raz]

I knew a fellow who had a pickup that had been converted to run on propane. His tank sat in the back bed just behind the cab. He had no issues with state inspection as far as I know. Other than the cost, the only other consideration I can think of is tongue weight. Raz

[cpaharley2008]

I got me one of these, you can see the amount of fuel and they are RVIA certified.
Lite Cylinder LC-25-00 Propane Storage Tank, 25 Lb

[Raz]

According to this site a fork lift cylinder is for dispensing liquid not gas.

Propane Cylinders - LP Gas Bottles


Jim, how often is the recertification on a fiberglass cylinder? Raz

[cpaharley2008]

AFAIK, it's no different than metal ones. And propane is liquid, at least what you can see inside the f/g tanks , it turns to gas once exposed to air, I think that is what the regulator does in addition to keeping the pressure a constant.

[David Tilston]

Originally Posted by P. Raz

According to this site a fork lift cylinder is for dispensing liquid not gas.

At Manchesters web site:
Manchester Tank: Forklift & Buffer Cylinders
I would like: 9315 - Aluminum 33.5# Liquid w/gauge - Fills through vapor opening

[Byron Kinnaman]

Originally Posted by cpaharley2008

it turns to gas once exposed to air, I think that is what the regulator does in addition to keeping the pressure a constant.

It turn into a gas, i.e. boiling point, at some low temperature. I don't remember exactly what it is. It keeps it's liquid state by being under pressure. The regulator reduces the high the pressure to something in 4 psi range. Most propane regulators are two stage, meaning the first stage reduces the pressure so that the second stage will have an easier time maintaining the proper, as you said, constant pressure.

The biggest difference between a vertical and horizontal tank is where the gas is taken off. A horizontal tank has to have a tube that's along the top side of the tank when it's laying down to get the LP in its gas state. Orientation is critical in a horizontal tank.

[David Tilston]

Originally Posted by Byron Kinnaman

It turn into a gas, i.e. boiling point, at some low temperature. I don't remember exactly what it is. It keeps it's liquid state by being under pressure.

The boiling temp of propane is -40 (C or F, they are the same)

According to Wikipedia, (so don't quote me)
Propane requires just 1,220 kilopascals (177 psi) of pressure to keep it liquid at 37.8 °C (100 °F)

Should a tank experience a catastrophic failure, then the propane would boil until, through evaporative cooling, it dropped to -40. Then it would boil as quickly as it could get heat from its surrounding. Depending on conditions, this could take some time.

[Byron Kinnaman]

Originally Posted by David Tilston

The boiling temp of propane is -40 (C or F, they are the same)

According to Wikipedia, (so don't quote me)
Propane requires just 1,220 kilopascals (177 psi) of pressure to keep it liquid at 37.8 °C (100 °F)

Should a tank experience a catastrophic failure, then the propane would boil until, through evaporative cooling, it dropped to -40. Then it would boil as quickly as it could get heat from its surrounding. Depending on conditions, this could take some time.

Thanks for looking that up. My memory was better than I thought. -40° was what I remembered.
177 PSI would probably be high enough to rupture copper pipe. Again, I'm too lazy to look it.

Now that I think about it, copper pipe would probably handle 177 psi. We used copper pipe for 150 to 155 psi air lines.

Got over the lazy and looked it up. Lowest burst pressure was around 475 psi.

[ken h]

It is very important to insure that the tank is sitting in the correct position if you rotate it in it's bracket you could get liquid ,the forklifts have bracket that holds them correctly. You can only use it for your l.p. system if it has a vapour outlet, you can't use liquid l.p. Your regulator can regulate vapour only ' if liquid gets in the line it will pass through and vapourize ,the l.p.pressure will go well past the max 14'' of w/c which is 1/2 lb . By the way all gas valves in R.V 's are rated for 1/2 lb

Hope this helps

[David Tilston]

Originally Posted by ken h

It is very important to insure that the tank is sitting in the correct position if you rotate it in it's bracket you could get liquid ,the forklifts have bracket that holds them correctly. You can only use it for your l.p. system if it has a vapour outlet, you can't use liquid l.p. Your regulator can regulate vapour only ' if liquid gets in the line it will pass through and vapourize ,the l.p.pressure will go well past the max 14'' of w/c which is 1/2 lb . By the way all gas valves in R.V 's are rated for 1/2 lb

Hope this helps

This is totally true! The whole problem I have is, how to accommodate all three sizes of tank? If you open the pdf in the first post, of this thread. You will see the procedure for changing a tank. There is a pin at the valve end that keeps the tank oriented correctly. There is also a central band around the middle of the tank. The band would be a fixed object, and the pin would need to be located in three different places. Hopefully they sell a bracket that adapts. There is also a small difference in the diameters of the steel and aluminum tanks. A rubber liner on the bracket would make up the difference, I think.


If there is any regulatory hurtle I expect to encounter it is with bracket. I would guess that it is considered an integral part of the system. As such, there will be rules.


I will be researching further.

[Frederick L. Simson]

They do make RV propane tanks that are oriented horizontally. I just saw one mounted on a 13' Scamp at the Lake Casitas Rally in October. The RV ones are designed to be mounted permanently to the RV and are not removed for filling. Their mounting brackets are part of the tank.

The only difference I see is that forklift tanks are separate from their mounting brackets, and are removable.

[DavidSo]

On the Lite Cylinder website they list the forklift bottles as "for liquid delivery only". That would suggest that the tanks are designed to deliver liquid fuel, not gas. They also make horizontal tanks for RVs. Those could be mounted in a cradle and removed.

Here is a good deal on cradle clamps:

http://www.amazon.com/Propane-Crawle...ref=pd_cp_hi_0

I'm replacing my dual steel tanks with a single 25lb Lite Cylinder. I'm building a vertical clamp rack to hold it using the clamps above.

David

[David Tilston]

Originally Posted by DavidSo

On the Lite Cylinder website they list the forklift bottles as "for liquid delivery only". That would suggest that the tanks are designed to deliver liquid fuel, not gas. They also make horizontal tanks for RVs. Those could be mounted in a cradle and removed.

Here is a good deal on cradle clamps:

Amazon.com: Propane Rock Crawler Tank Bracket Forklift Heavy Duty: Home Improvement

I'm replacing my dual steel tanks with a single 25lb Lite Cylinder. I'm building a vertical clamp rack to hold it using the clamps above.

David

I have recently discussed this topic with my brother. It is his opinion that the increased surface area of boiling fluid makes a horizontal tank a better cold temperature producer of vapor, especially when it is half full. This is important to him in his 5th wheel toy hauler when it is near -40. Makes sense to me.


Since the tanks that Manchester sell actually fill through the vapor port, I assume that there is some ease of filling benefit to having one.


I have been struggling to find a use for the liquid port. I may be reading it wrong, but I think they fill the 1# bottles off of it.
Manchester Tank: 1# Refillable Cylinders


I really don't work for Manchester! But they do make propane cool/green. A propane weed wacker?

[Night Sailor]

I saw a propane rail car on fire once. You could see it two miles away. It was flaming right out of the top. The firemen wisely chose to let it burn itself out. I think there is some cooling due to the expansion from liquid to gas which offsets the heat generated. I watched for a long time and the flames was constant so i there was no ablation at the opening.

I don't think these things turn into rocketsz

[WildBirder]

Be careful of maximum carrying regulations if you plan to take ferries.

Living in BC, a month on Vancouver Island is on the agenda. Most ferries have restrictions on the amount of propane you can bring. BC ferries is two 35# tanks per RV. (They don't specifiy if they let you have on 70#)

Transportation Canada also has regulations of a maximum of 500kg (2200#) for an open vehicle and a max of five 30kg (66#) tanks in an enclosed vehicle. I think you can squeek under those numbers

This thread is giving me great ideas…my poor wallet.