Fuel tank gauge

[Phil S.]

I have a 550 gallon above ground fuel tank.  It is filled from the deck above so the height of the fill is well above the tank with 5-6' of 2-1/2"pipe leading to the tank.  I need a way to know the level of the fuel in the tank.  Is there a gauge that will work in that situation?  I'm worried that if the tank is overfilled into the fill pipe, fuel could leak out of the gauge and make a mess.

Phil

[R Clark]

I think that most gauges are built to be sealed against that kind of leakage, no?

I recently looked online at how to determine the level of fuel in large propane tanks.  Some of the YouTube video I came across used a temperature sensitive tape adhered to the tank exterior that changed color on the outside of the tank.  It worked by the user pouring warm water over the tape.  Above the fill level, the tape turned one color, below the fill level it was a different color.  It could work for a regular liquid fuel like diesel, kerosene, or gasoline.

If a gauge is not possible, then I think I'd look for a flexible dip stick to measure it the old fashioned way.  Of course, that presumes you can get to the top of the filler neck easily.

[TDKPE]

Isn't there a fill alarm, aka a 'whistle'?  That's the normal method of determining when the tank is near full, at least for the use of the person filling it.  Installed at the top of the tank, with the vent pipe coming up from there, the sound travels through the vent to where the driver connects the fill hose.  You can get them with a longer than standard stem so the driver gets earlier warning than with the standard size.

And I agree, the gauge should be oil tight, even if overfilled.

https://www.granbyindustries.com/petrole...m-whistle/

[Stwood_]

Fitting on bottom. Fitting on top. Clear vinyl hose connected to both.

[R Clark]

Fitting on bottom. Fitting on top. Clear vinyl hose connected to both.

Yeah, I was thinking that, too, when I responded earlier.  Couldn't find a way to describe it as succinctly as you did!  


Downside to that, of course, is that the tank will have to be empty (and perhaps purged) before drilling into it.

[Stwood_]

Yeah, I was thinking that, too, when I responded earlier.  Couldn't find a way to describe it as succinctly as you did!  


Downside to that, of course, is that the tank will have to be empty (and perhaps purged) before drilling into it.

Hmmm yes, unless there's a plugged hole on the bottom somewhere. There usually is on most all steel and alum tanks.

[DieselDennis]

So where do you want the gauge to be?  Where do you want to see the readout?  

These people may have something that will work:

https://rochestergauges.com/

And put me in the camp who would just use an old fashion "dip tube" (aka, stick).

[Phil S.]

Thanks for the replies guys.

That heat sensing tape sounded pretty neat - easy to apply, no chance of tank leakage - found a dealer here-
https://www.thermographics.com/consumer/...-indicator
but I don't think the difference in temperature above and below the fuel oil level would be great enough to make it work.  Discharging a propane tank will put frost on the outside of the tank, but I think the fuel oil in a tank would be about air temperature.

The whistle would be okay to let me know when the tank is nearly full, but I'm more concerned when the tank is nearly empty and I need to get the fuel guys to fill it up.  I'm on autofill, but I'm not sure the supplier is thinking there will be parts of the year when he won't be able to deliver fuel whether I need it or not.

I'm reluctant to use a sight glass type of gauge, providing a potential source for leaks with a hole into the bottom of the tank.  The only hole near the bottom of the tank right now is where the filter and discharge line are connected.

Using a dip stick would also be tough.  The fill pipe has two 90° bends in it.  The top is about 8" above the top of the deck, it drops about 3' to the first 90 and then runs horizontal for 6' to the next 90 that drops another 8" or so to the tank.  There are two 2-1/2" plugs in the top of the tank (in addition to the two that are used for the fill and the vent), but they need to be sealed in case of an overfill and I only have about 2' of clearance above the tank and the bottom of the deck.  The tank is about 4' in diameter.

This tank replaced a 275 gallon tank.  The old tank didn't have enough capacity to last the winter so I had a couple of 55 gallon drums next to it that I'd transfer when the fuel got low in the main tank, a headache the bigger tank was meant to avoid.  The driveway into my place is half a mile long over a hill and if there's snow the fuel company won't deliver so I want to be sure to have enough fuel to carry me from the end of October to April, the stretch when the driveway might be icy.

The old tank had a float gauge in it, not particularly accurate, but good enough to tell me if the tank was full, near empty or somewhere in between.  It threaded into one of the plug holes in the top of the tank and had an indicator on top of it that would rise with the level of the fuel.  The indicator would rise maybe an inch for each 10" of fuel in the tank.  I'm not sure how oil tight that gauge was, but the service man was standing next to the tank when he filled it rather than on the deck above so there was less of a chance it would be overfilled.

My inclination now is to see if I can find a float gauge that will work in the bigger tank and is oil tight.  Then my worry will be if I can fit it into the tank given the limited clearance above it.

Phil

[goaliedad]

Run the sight gauge from the output line instead of the tank itself. That way no new joke in the tank. There should be a valve on that line already, turn it off and install the gauge. Easy peasy

[R Clark]

...
That heat sensing tape sounded pretty neat - easy to apply, no chance of tank leakage - found a dealer here-
https://www.thermographics.com/consumer/...-indicator
but I don't think the difference in temperature above and below the fuel oil level would be great enough to make it work.  Discharging a propane tank will put frost on the outside of the tank, but I think the fuel oil in a tank would be about air temperature.

Regarding the tape:  In the video I saw, the user installed the tape and then to get a fast read, the user poured warm water down the side of the tape.  the tape obviously changed color quickly, and then the tape cooled at different rates above and below the level of the liquid inside, giving the differential temp and hence the reading.  Perhaps a bit awkward to go out in the weather to do that, but not a great deal of bother more than going out and checking a dipstick.