Propane level gauge- howzit work?

[TinKicker]

You are definately right--the forklift will NOT run off vapor! Tried it. And you sho ain't gonna push dat baby out of a crowded parking lot with a pallet of stock in the air!
Somebody out there might know where you could get a valve that would allow only vapor out of those tanks. I assume their siphon tube is engineered longer to remain "under water" all the time, just like in the NOS tanks we use.

[brian_bp]

Somebody out there might know where you could get a valve that would allow only vapor out of those tanks. I assume their siphon tube is engineered longer to remain "under water" all the time, just like in the NOS tanks we use.

Yes, both vapour and liquid fittings are arranged with internal tubes (if necessary, depending on valve location) to end in the top or bottom of the cylinder, as appropriate. Similarly, the pressure relief is at the vapour end, and if the cylinder has an 80% fill level bleed valve (many don't) it is connected to a dip tube which ends at that level. Thus, all propane tanks really care which way is up! Barbecue tanks are dead simple because they just need one valve body screwed in the top, and ones filled by weight and without an OPD (which means most of them here until very recently) don't even have a float or dip tube sticking down into the cylinder.

The Manchester aluminum 33.5# forklift tank is shown on their web site in cutaway; it looks like it could be used vertically or horizontally, with the tubes leading to vapour and liquid spaces going to opposite "corners" of the tank. Their tanks also come in both liquid and vapour (or both) versions. The specifications for Worthington forklift cylinders show that they have a liquid service valve, but also have a plugged port for vapour service: I assume you can remove the plug and screw in a vapour service valve.

I looked into getting a large tank for long-term use with a larger trailer. I can easily get a 420 lb upright tank, but I wanted a horizontal cylinder to sit low on a trailer (so I could haul it to a station for filling). I can't readily get a really suitable one, because the vapour-service tanks used on motorhomes have the mounting brackets on the top (for hanging, not sitting on a trailer), and the ones used in the the back of pickup trucks using propane as engine fuel are set up for liquid service.

Some companies will make a tank with whatever combination of fittings is needed, if one is willing to pay for that... in most cases, I think we're stuck with what they come with.

What does this have to do with a gauge? Well, all of these big tanks usually have float-type level gauges, but with all the various plumbing fittings, everything has to be the right way up. In some applications (such as motorhomes), there is a sender instead of a dial, so it can have a remote display, just like a car's gas tank.

[BPFox]

Here's how I tell, when the flame goes out, time to change the tank.

But seriously, losing the ability to cook and heat in the middle of a trip is not fun. I assume that my travel trailer has two tanks only so the second one can be used as reserve, not because people commonly use 40 lb of propane in one trip.

Thats the prime reason for two tanks. Run one empty then switch tanks. You maximize your LP gas dollar that way. When I had my travel trailer it had twin 30lb tanks. Took almost all summer to burn up the first tank.

[BPFox]

You are definately right--the forklift will NOT run off vapor! Tried it. And you sho ain't gonna push dat baby out of a crowded parking lot with a pallet of stock in the air!
Somebody out there might know where you could get a valve that would allow only vapor out of those tanks. I assume their siphon tube is engineered longer to remain "under water" all the time, just like in the NOS tanks we use.

Your forklift tank will have a positioning hole and your tank bracket will have a positioning pin. Make sure the pin goes in the hole and you are all set. If you don't do that you could run out of gas with plenty of gas still in the tank.

[brian_bp]

...
Your forklift tank will have a positioning hole and your tank bracket will have a positioning pin. Make sure the pin goes in the hole and you are all set. If you don't do that you could run out of gas with plenty of gas still in the tank.

Although I have never changed the tank on a forklift, I heard this is how they ensure that the cylinder is used with the right side up. This is important not only to keep the liquid outlet in the liquid, but to keep the pressure relief valve in the vapour and the gauge working (assuming that it works when horizontal).

[Lgboro]

I just picked up a composite tank and can see how much propane is left in the tank.

[BPFox]

...
Your forklift tank will have a positioning hole and your tank bracket will have a positioning pin. Make sure the pin goes in the hole and you are all set. If you don't do that you could run out of gas with plenty of gas still in the tank.

Although I have never changed the tank on a forklift, I heard this is how they ensure that the cylinder is used with the right side up. This is important not only to keep the liquid outlet in the liquid, but to keep the pressure relief valve in the vapour and the gauge working (assuming that it works when horizontal).

That is 100% correct. It is a very common mistake to just throw the tank in the bracket without paying any attention to the locating pin. I can't tell you how many service calls I have been on where folks complained that their forklift quit running even though there was still gas in the tank. They get smart real quick when you charge them $50.00 to rotate their LP tank one quarter turn. Works just like a spray paint can. Turn it the wrong way and you get no paint. Peace.

[brian_bp]

I just picked up a composite tank and can see how much propane is left in the tank.

I like the idea of these composite tanks, which also save some weight. They are pricey, though, and like any tank other than the generic 20 lb "barbecue" unit, you can't trade it for a full one at a store which does exchanges, you have to go to a real propane station.

[wlooper89]

With the teardrop an eleven pound tall skinny tank lasts us several weekends. Got it at REI and it is easy to refill at Ace Hardware. It weighs 12.1 lbs empty and anything above that is propane. Conveniently we have a set of old scales in the garage, so just set the tank there and presto one knows the amount of propane remaining. This is also less depressing than keeping the scales in the bathroom.

Bill

[wlooper89]

Our tall skinny 11 lb. tank makes a tinkling sound when shaken or if it is riding inside the car. Does that mean there is a float and that the tank could accept a quantity gage? There is not a gage on it now. The sound would drive one batty on a trip, but normally the tank is mounted on the trailer so we do not hear it.
So far I guess we are in the use-it-until-the-flame-goes-out crowd. Although removing the tank from the trailer for use gives me a pretty good idea if it feels light. Previously we used the one lb. canisters with our portable stove and have one left over from when we got the tank. I carry the one pounder to serve as a backup in case we deplete the larger tank in the middle of cooking.

Bill

[brian_bp]

Our tall skinny 11 lb. tank makes a tinkling sound when shaken or if it is riding inside the car. Does that mean there is a float and that the tank could accept a quantity gage? There is not a gage on it now...

Any Overfill Prevention Device uses a float to shut off filling at the 80% volume mark. The Manchester SureFlame does use this float for its gauge, and I assume that The Tank does as well, but the system only works with a valve body that's designed for the purpose... no adding a gauge to a tank with a valve body that wasn't specifically designed for SureFlame or The Tank.

The larger tanks with gauges use separate hardware for the OPD (if so equipped) and level gauge (each screwed into their own ports), but there's no port in which to install a level gauge in a common small vertical tank... there's just that one threaded hole (port) in which the all purpose service valve / OPD / relief valve / bleed valve body is installed.