Small Cabin

Small Cabin Forum
 - Forums - Register/Sign Up - Reply - Search - Statistics -

Small Cabin Forum / Off-Grid Living / Need Propane Tank Level Indicator or Warning Light
Author Message
paulz
Member
# Posted: 4 Jan 2017 13:17
Reply 


The small town where my cabin in located has a propane backup generator that powers the restaurant, small store and firehouse when the grid power goes out. Last night the power went out and the propane tanks were empty, oops. We currently have two 100lb. tanks connected such that when one goes empty it switches to the other. Problem is nobody really tracks how long the generator runs (it also runs for 15 minutes a week for testing) and the tanks are in an area nobody pays much attention to.

So the 'boss' has asked me to figure out how to make sure this doesn't happen again. I'm new to propane myself since I built my cabin, is there a warning light system, level gauge, scale or something to alert us when we need to fill a tank?

MtnDon
Member
# Posted: 4 Jan 2017 14:22 - Edited by: MtnDon
Reply 


The most dependable and least costly method might be to simply have someone designated to check the regulator indicator once a week or even monthly, depending on how long it takes on average to use 100#. That assumes there is an indicator; the two I have do use a green/red indicator that changes when the first tank hits empty. They could also log the date they checked so anyone else could affirm it was being done. As soon as the switch over indicator shows red you refill the empty tank. That is what we have done for years. We also have a third tank that gets switched into the coupled pair when one hits empty.

MtnDon
Member
# Posted: 4 Jan 2017 14:25
Reply 


There are pressure gauges that can give an idea of the level, but they are extra cost and still not useful if nobody checks. A scale could be used but that likely means finding one that can sit out in the weather.

groingo
Member
# Posted: 4 Jan 2017 15:56
Reply 


You can use an infrared thermometer, just scan from top to botton of the tank and just look for a temperature drop, do that a couple times to verify and you have it....coldest is where the propane level is.

creeky
Member
# Posted: 4 Jan 2017 16:17
Reply 


Or splash hot water on it and feel where the tank goes from hot to cold.

Steve_S
Member
# Posted: 4 Jan 2017 16:41 - Edited by: Steve_S
Reply 


http://fuelminder.biz/lpg%20and%20propane%20gauges.html

Maybe something there would be suitable, also check amazon & ebay.

There is this one on Amazon, a GasLow with Remote INdicator https://www.amazon.com/Gaslow-Remote-Propane-Monitor-Gauge/dp/B0028F6WIY/ref=lp_11879 679011_1_1?srs=11879679011&ie=UTF8&qid=1483566341&sr=8-1

paulz
Member
# Posted: 4 Jan 2017 17:17
Reply 


Thanks guys. Are pressure gauges accurate enough since they measure the tank pressure, not the level of liquid? Some of those pressure gauges have remote indicators and even wifi/internet!

MtnDon
Member
# Posted: 4 Jan 2017 18:13 - Edited by: MtnDon
Reply 


Because propane is stored as a liquid a pressure gauge provides little useful information. Other gases such as oxygen and nitrogen are stored in a compressed gas form, so with those a pressure gauge gives an accurate assesment of how much is left. The liquid propane evaporates to occupy the space above the liquid. It stops evaporating when the pressure reaches equilibrium. The level can be at full or at 25%, makes little difference to the pressure. However, the propane gas pressure varies widely with temperature. Boyle's Law.


A cylinder with liquid propane in it will have a gas pressure of about 220 PSI at 110 F, 125 PSI at 70 F, 30 PSI at freezing and less than 5 PSI at -40 F/C. The pressure will change from summer to winter without using any propane. Once the liquid has all been gassified the pressure will fall quickly as the gaseous propane is used.


If propane was being used at the same rate the gauge will show the cylinder to be full longer in summer than in winter.


With that in mind I find it hard to see how a pressure gauge on a propane cylinder can give you any real idea of how much liquid propane is left. I'd feel more confident in splashing warm water on the cylinder or simply doing as I posted above about using an auto switch over regulator and observing the red/green indicator.

Our Class C RV had a level system in its ASME propane tank. That used an actual float gauge inside the tank with a dash gauge like the gas/diesel tank gauges we are all used to. However those can not be fitted to a portable cylinder.

paulz
Member
# Posted: 4 Jan 2017 20:36
Reply 


Yes I think it's more important to know when we are on the backup tank than the actual level in the tank(s). I found this remote indicator kit for the changeover valve so the light could be mounted in the office or someplace visible. We are also getting two extra full tanks tomorrow so when the light comes on, switch to a new tank, fill the empties later.

http://rvpartaccessories.com/products-page/rv-lp-products/remote-lp-changeover-indica tor-rci-24-by-marshall-products/

MtnDon
Member
# Posted: 4 Jan 2017 21:35
Reply 


That looks like a useful devic

But don't let the "later"in fill the empties later,get to be so much later that it is forgotten about.

drb777
Member
# Posted: 4 Jan 2017 22:37
Reply 


I don't see why you wouldn't talk with your local propane supplier about setting a small-ish, say 300 lb tank. While there may be a small yearly rental, the supplier may waive the charge when you tell him it's for the firehouse back-up power, and you agree to let him be the propane source. With the larger tank you'll have have a reliable float gauge, and benefit from a lower per gallon price vs. 100 lb bottles. I assume natural gas via. pipeline isn't available, it is safer, easier & cheaper than any liquid fuel.

DaveBell
Member
# Posted: 5 Jan 2017 00:08 - Edited by: DaveBell
Reply 


A couple of these might be simple enough.

https://www.youtube.com/watch?v=Sj4hqYFNRqY

or.....
https://www.youtube.com/watch?v=ih-aFvTdfzs

paulz
Member
# Posted: 5 Jan 2017 11:38
Reply 


They did check about getting a larger tank, that was apparently nixed due to the small and inconsistent amount used. No piped in gas in the town. I checked into the temperature strips used on the 20lb. tanks but I haven't seen any long enough to use on larger tanks. They did get two more 100lb. tanks yesterday and say the changeover valve does have and indicator so they're good with that and keeping an eye on it. I'm still going to see if we can add a warning light extension where someone won't miss it.

Thanks again for the replies, I knew I came to the right place!

DaveBell
Member
# Posted: 5 Jan 2017 15:50
Reply 


Quoting: paulz
I checked into the temperature strips used on the 20lb. tanks but I haven't seen any long enough to use on larger tanks.


Quoting: DaveBell
A couple of these


paulz
Member
# Posted: 11 Jan 2017 09:04 - Edited by: paulz
Reply 


The Chief now wants to tie in the extra two tanks he bought, such that two tanks draw at the same time, then when the regulator switches over it draws off the other two. Bad idea? So I would need a pair of hoses, each able to fit a tank on one end with a T on the other end that fits a tank and the male fitting on the existing hose. Off the shelf item or something I'd have to make up?

Edit: thinking this through a little more I would tee them at the regulator with standard pipe fittings.

MtnDon
Member
# Posted: 11 Jan 2017 09:48
Reply 


DIY, a tee on each side of the regulator with two hoses attached to each side.

I see this as a lousy idea. Now instead of the two tanks running dry because nobody bothers to check, all four will run dry. (the pessimist as to how people fail.....)

paulz
Member
# Posted: 11 Jan 2017 10:20
Reply 


Good thinking, maybe the primary two paired, single tank on switch and one unconnected for last ditch.

Malamute
Member
# Posted: 11 Jan 2017 11:56 - Edited by: Malamute
Reply 


Quoting: paulz
They did check about getting a larger tank, that was apparently nixed due to the small and inconsistent amount used


Can you elaborate on that? Who nixed it and for exactly what reason?

When I was living in my motor home, after dealing with taking my collection of smaller tanks in to get filled, the propane company suggested getting a larger temporary type tank. I don't recall the size, it looked like the large yard tanks, but was smaller. Due to its size, it wasn't required to have the same regulations as the larger tanks in how it was set up. It sat on wood blocks and was set up wherever was handy. I ran a long rubber hose to the motor home. The propane company came on whatever time interval I requested and checked the level, or would wait for a call to fill it. The tank rent was something like $40/year. I HATED dealing with moving tanks, and really hated running out, or messing with changing tanks if/when I ran out. I figured that small (100-150 gal?) tank was one of the best moves I ever made in propane before just getting the full size 250 gal tank that does my cabin now.

Buying more portable tanks seems like an expensive way to cover the situation. I'm surprised if the propane company wouldn't rent you a small temp type or larger fixed tank because of low use. They make money on the rent at least, and you apparently are using some propane.

After getting the larger tank, I filled my portable tanks and just kept them for emergencies. I think they lasted several years, I ended up using them for my radiant heater on job sites. Keep in mind, with the large yard tank, IF you run out and they cant come right away, you can detach the short hose from the big tank and hook it up to your small tank to get by for short periods. Ive done it several times with the BBQ size tanks. I don't check mine very often as the 250 will last about a year.

Running out of propane because nobody is organized enough to check the level monthly, bi-monthly, or quarterly, is operator error, and easily corrected with writing on the calendar to check it on whatever interval ensures not running out. Most cell phones can be set to give notice for whatever events need remembering also. Getting 3 people to agree to do it, maybe it can get done though. Have to say, with the things that rely on it, I'm really surprised nobody can get it together to check the propane level or refill the tanks on a schedule. If they are only half empty, so what, just DOING it regardless of level at regular intervals will keep them from running out. Criminy.

old greybeard
Member
# Posted: 11 Jan 2017 12:31
Reply 


Buy a 100 gallon tank, around $400 here. Save $.80 a gallon on propane.

paulz
Member
# Posted: 11 Jan 2017 13:25
Reply 


These are 100lb. tanks. The story I was given on why not a larger tank was that the area where these are does not meet clearance requirements for a larger tank, and hard for the propane company to get back and fill, plus in the summer only a bit of propane gets used on monthly generator tests. The real story might be that the chief got worried when we ran out and rushed out to buy the two more 100lb. tanks. In any case now that it happened I'm sure we all will be keeping a closer eye on it.

paulz
Member
# Posted: 13 Jan 2017 18:14 - Edited by: paulz
Reply 


I pulled a hose off today to see what I need for a T. It is not pipe thread as I thought but flare. I tried to loosen the brass reducer off the changeover valve but it was very tight. Standard RH tread would it be?
0113171101_HDR.jpg
0113171101_HDR.jpg


OlinOvid
Member
# Posted: 7 Oct 2019 12:55
Reply 


Hi...there is a voltage source up in the indicator panel. The tank gauge is nothing more then a variable resistor.
Short or disconnect the gauge wires, near the tank, and see if it reads full on the panel inside.If either test makes it read full, the tank sender/gauge is bad.

Your reply
Bold Style  Italic Style  Underlined Style  Thumbnail Image Link  Large Image Link  URL Link           :) ;) :-( :confused: More smilies...

» Username  » Password 
Only registered users can post here. Please enter your login/password details before posting a message, or register here first.