Are Oil Tank Level gauges accurate?

The Wire Nut

I have two 275 gallon tanks that supply my Burnham with a Beckett AFG with a .75 nozzle. I recently had it professionally serviced. It's a steam system and this fall I repiped it with a drop header, etc. There was a whole thread about that and the value of drop headers (Hi, Ken!).

In any case, I get lots of nice steam and the radiators get nice and toasty. When it's cold out the boiler will run for about 1 hour 20 minutes on average and then not run for a couple of hours. We are there generally only on the weekends and keep the temp between 66 and 68 depending on how cold we feel! While we are not there it's set to be 61 deg.

We had a fill on 12/23 of 330 gallons. As of last Sunday we were down to 3/4 tank according to the gauge. This means we burnt 143 gallons of fuel in just over a week. Granted we were up there for the week between Christmas and New Years but this sounds like an awful lot of fuel...

So, I wonder; a) is that a normal amount of fuel for a fully insulated (Icynene foam) house about 1500 sq ft or b) are those gauges just not too accurate, like a lot of car gas gauges....

Thanks...

<A>

kevin coppinger_4

unless you...

refill the tank it really hard to say...the float can get bent if they are not installed right...some times the driver of the oil truck will not fill it to the top of the tank...which is better than overfilling it...how is your venting on the steam main? kpc

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The Wire Nut

Hot air...

The tank was just filled on 12/23, is that what you mean? I'm vented quite well, thanks to Steamhead. The shorter main has a Hoffman 75 and the longer main has two Gorton No. 2 vents.

Pinball

Hey Alex,

First of all most guages are only marginally acurate, they are measuring liquid level not gallons. What I mean by this is, if you look at your tank you'll see that it is narrower at the top and bottom.The liquid level drops faster for the first 8-10 inches and at the bottom 8-10"

also, in our area, the whistle/vent are extended into the tank approx. 4-6" (the point that the driver stops filling)

This is for oil expansion as it heats up to inside temps.

The odds are pretty good that 143 gallons is NOT a true number.

hope this helps

Al

D Logan Ireland Oil Co Inc

If you give me some more info I can help you out. Are these tanks piped in tandem when they are filled or are they filled with separate fill pipes. Keep in mind that a 275 tank with a vent alarm shuts off at approx. 250 gals. So therefore if your tanks were filled correctly you would have approx.500 gals. together. Standard 275 tanks are approx 42" in height so 3/4 of a tank would leave 31 1/2" of oil remaining assuming your tanks are balanced. According to my oil tank chart you would have approx. 215 gals in each tank or 430 gals remaining together. So as I do the Math I see 500 gals when filled minus the remaining 430 gals. leaves me with approx. 70 gals used during that time frame. In a 10 day time span you were averaging 7 gals a day. That doesn't seem unreasonable to me. The weather of course is the determining factor as to your usage.

Constantin

Yup...

...my Roth tanks may be nearly linear WRT fill vs. fluid height, yet the oilman never fills the things to "full". I have yet to see a post-fill level above 7/8, even after the oil comes to temperature.

On the other hand, I'm not going to argue with the safety aspect of keeping excess air in the tank to ensure that the oil doesn't contaminate anything.

I intend to keep a track of the boiler on/off hours via the Vitotronic 200. That combined with a pretty well-defined nozzle should make consumption calcs a snap. Things will get trickier if Viessmann ever gets around to adopting their Vitoplus burner for the Vitola (i.e. modulation), but I'll gladly cross that bridge when I get to it.

If Alex has a Tekmar controller, he can also usually discover the burn time.

The Wire Nut

Slippery slope...

would seem to be the way of the oil gauge... What Pinball says makes sense... I think I remember that the gauge glass divisions are not equal which may be an attempt to equalize the difference between the various widths of the tanks. But it would never be accurate...

The tankes are in tandem and filled by one pipe. And his math makes sense as to the consumption. I think we calculated that it should be around 7 - 10 gallons a day... I'll have to see how many gallons we get at the next fill...

Hey Constantin, happy new year... I wish I had all that fancy Tekmar equipment! You know I like to play with those types of toys...