"A" frame bottle location & plumbing setup

[noseoil]

I'm wondering about a simple gauge setup for my system to monitor the propane level in the tank. The high pressure regulator side has a threaded hole with an allen screw in it on the top (facing up), on the inlet hose side. Wondering about attaching a small pressure gauge (0-200 psi, 1" dia.) in this location, to monitor the tank contents. I found some small tank gauges online and they will fit in my installation. Couple of questions arise around this stuff.

1- Will there be a problem with DOT or anyone else, if they want to be picky about my setup on the highway with a non-standard gauge? (I now have regulator covers in place, they are removed in this picture)

2 - Will a simple pressure gauge function properly to monitor the tank level in this location and actually work well enough to use?

Here's a couple of pictures to illustrate what I'm thinking about. The left side regulator shows a small brass set-screw in place now, but I can fit a very small dial gauge to that opening and still have clearance against the tongue box where it's mounted. The gauge is a simple pressure gauge from a paintball setup and 200 PSI should be sufficient for a propane tank. Thanks & all answers appreciated.

[Dale M.]

A pressure gauge will only tell you if a tank has propane or not.... The science is...

If there is liquid propane in tank it boils off into a vapor, the amount of vapor in tank relates to temperature and temperature is what causes the vapor and the PRESSURE.... So if there is any liquid in tank, (full or almost empty) the pressure registered on gauge will be in relationship to temperature not volume of liquid... Its a sliding scale as temperature goes down pressure goes down, and as temperature goes up pressure goes up.... So unless tank is empty the gauge will always so pressure in relation ship to temperature NOT what actual amount of propane (liquid) in tank.. Note at approximately 70° f. tank pressure is approximately 120psi...



OR another way...



Two ways to see how much propane (liquid) is in tank...

One is to boil a pan of water and then drizzle it down side of tank, water will warm shell of tank, down to lever of propane (liquid), you run your hand down side of tank and feel for temperature change, where temperature changes from warm to cool the is line where liquid is in tank..

Second method requires a scales, propane weighs 4.25 pounds per gallon, tanks usually have TARE weight of tank in safety collar, usually newer tanks weigh about 20 pounds (TARE) , so if you weigh tank with propane, and it weighs like 33 pounds you subtract tare weight of tank (33-20=13) so if you have 13 pounds of propane in tank you divide 13 by 4.25 (13 / 4.25 = 3.05) so you have pretty close to 3 gallons of propane in tank....

A gauge can fool you by showing good pressure till tank no longer has enough liquid propane in it to create vapor/pressure then you are suddenly empty (no pressure reading) ... Gauges are sort of a joke on the public that needs something visual to give them indications that all is well or not well....

Another solution may be one of the new semitransparent tanks where you can actually see the level of fuel (liquid) in tank...



Be aware the when looking for a transparent type tank there was a factory recall on SOME that were not safety tested correctly... Not all transparent tanks are in this recall, you need to do research and have tank serial number to see if tank is good or not...

To answer your question, if plugged port on regulator is for gauge, by adding gauge it will indicate there is pressure in tank and but necessarily how much propane is in tank......

Dale

[noseoil]

Dale, thanks for this reply. I was having trouble understanding how a "regular" propane tank gauge (the in-line type) actually worked, if it was simply measuring gas pressure. I knew that with propane, pressure is a function of the tank's temperature, so the gauges they sell were "different" than I could understand. Perhaps they should just sell a "digital" idiot light that comes on after the tank is empty to let us know when we're S.O.L. on cooking for that meal. Thanks again for the great reply. tim

P.S. Perhaps there should be a sticky with the heading "Propane Snake Oil for Sale"

[Dale M.]

About the only people that gets it right is some of the propane grill manufactures like my WEBER, it has a spring scales the tank hangs on and it shows approximately how much propane is in tank ( by weight) on a scales that reads "FULL - 3/4 - 1/2 - 1/4 - EMPTY" or some thing like that... Unfortunately it wont work to well on TD...

Best method is hot water, my dad taught me method 55+ years ago and it has never failed me...

Dale

[High Camp Trailers]

I like the KISS method (usually selected after trying every other Not-Simple method!).

I have used a stick-on gauge like this one http://www.leevalley.com/US/Garden/page.aspx?p=55008&cat=2,40733,40996&ap=1 and find it to be an excellent, low-cost, simple to use solution to the LP tank level question. I would probably stay away from a magnetic version, so look for one that is adhesive. Since most of us boil water for coffee or tea in the morning, you are never really put-out to check the level on the road. You do need boiling water for it to really work well.

-Dennis

[Dale M.]

I like the KISS method (usually selected after trying every other Not-Simple method!).

I have used a stick-on gauge like this one http://www.leevalley.com/US/Garden/page.aspx?p=55008&cat=2,40733,40996&ap=1 and find it to be an excellent, low-cost, simple to use solution to the LP tank level question. I would probably stay away from a magnetic version, so look for one that is adhesive. Since most of us boil water for coffee or tea in the morning, you are never really put-out to check the level on the road. You do need boiling water for it to really work well.

-Dennis

Only argument against stick on (adhesive backed) is if you exchange tank it goes with tank and somebody else has advantage of your measure...

Dale

[High Camp Trailers]

True, Dale. I think Noseoil bought his own, but yeah I might try the magnetic version if I were using an exchange tank so I could take it off... I've just heard the magnetic ones can be hit or miss with "stickiness".

[Dale M.]

Hot water method has never failed me....

Dale

[noseoil]

I realized I hadn't posted a picture of the back of the line installation, so here's the back end at the galley. The brass fitting is a quick-disconnect, which is tucked in under the back of the frame for an extra line out for a grill, lantern, stove, etc. The two stage regulator should help deal with the stove & oven (3 burners total), as well as any spikes in consumption due to temporary connections of other things on the QD.

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I was concerned about road stuff kicked back under the trailer at speed, so hopefully, here's the solution against rocks & alligators. The pipe is black iron, but the brass is pretty soft and could take a direct hit & shear off because it's at right angles to the line.

[noseoil]

Follow-up shot as things continue. Lots of changes since last year. Here's the galley now & we're getting closer to having things done. More pics to come as progress continues on the build. I'll complete this installation & show how things worked out when it's up & running, so others can do a good job from the start. The original installation in front won't work with this stove, as I found out later....

The galley now with the stove getting ready to be installed. The 1/2" black pipe is reduced to 1/4" then there's a shut-off valve to make sure things are "off" during towing. The tank has it's own valve up front, but I wanted to be able to shut off the gas in the galley if I wanted to, just in case. The fitting you see on the end is to allow for a swivel connection on this end, so the hose can be twisted into place & tightened to form a loop in the line, so the stove can track in and out & not cause kinks or binding. Without this swivel connection on one end of the hose, I would have to tighten the stove by "rolling" the entire unit on the hose.

[lrrowe]

True, Dale. I think Noseoil bought his own, but yeah I might try the magnetic version if I were using an exchange tank so I could take it off... I've just heard the magnetic ones can be hit or miss with "stickiness".

I bought a cheap bathroom scale at a flea market and put it under the scale to read the weight of the tank while in use. But I now only have the tank on the ground. It will less helpful when I permantly place the tank on the tongue.

Otherwise I have used the hot water trick.

[noseoil]

Finally at the propane stage in the build now, but figured I should update the thread to finish things off & tie up this loose end. I've set the bottle in place & had to use a 30# variable regulator to change the gas flow to work with the Camp Chef stove. An 11" water column pressure from the standard regulator won't allow the stove's burners to light, since it has its own diaphragm-type regulator attached already (to step down the pressure form a standard 1# bottle).

Perhaps someone knows of a fitting which will allow a low pressure line to work with the stove & bypass the factory regulator? I didn't find one. A shot with the bottle in place & plumbed into the hard line in front. I had a local company make up the flex lines for me. They do hydraulic & LPG lines, so it's handy to have them available near work, cheaper than buying off-the-shelf stuff as well.



The stove line with the regulator attached & ready to install in back in the galley. The line is longer & forms a loop, so it can unwind as the stove tracks in & out on full extension drawer guides.



The stop latches I used to hold the stove from moving while under way. They're just bathroom stall type latches, which drop into slots in the deck. Had some left over diamond plate so I made trim pieces to finish out the holes.

[bobhenry]

Speaking of propane ....... I finally got brave and left the gas on overnight in the caboose. The next day I decided to light the burners on the rv stove. I thought I had a hint of propane smell when I entered the caboose but dismissed it as paranoia after a few more breaths. Well the top of the stove hopped up about 4 inches and the resulting fire went out rather shortly. The double female adapter was leaking at the stove distribution log. I tightened it and took a lit match and checked for a leak and it still supported a flame so I re tightened the connection and now it's gone.

[Dale M.]

Speaking of propane ....... I finally got brave and left the gas on overnight in the caboose. The next day I decided to light the burners on the rv stove. I thought I had a hint of propane smell when I entered the caboose but dismissed it as paranoia after a few more breaths. Well the top of the stove hopped up about 4 inches and the resulting fire went out rather shortly. The double female adapter was leaking at the stove distribution log. I tightened it and took a lit match and checked for a leak and it still supported a flame so I re tightened the connection and now it's gone.

Good argument for turning propane off after each days use....

Dale

[noseoil]

Just a quick update on the propane use. Happy to say we've had no problems with the setup so far. Only about 2,500 miles on the trailer so far, but this will be changing soon. A longer trip is planned for this summer. That will be a bigger test of use as we'll be running every day for cooking & coffee, dishes, etc.

I filled up the 10# bottle this week & here's what we've used so far. Since our first trip to Nevada last November, we used a total of 6# of propane. This includes coffee on trip mornings, a few batches of cookies & sweet rolls along the way, dinners while camping, hot water, cobblers & general use over the last 6 months. The only time we use is for cooking, no lights or big grilling setup for groups of people.

The stove is really a great thing to have & the oven is wonderful for pumping out smells in the morning on sweet rolls.