Condinsation In an oil tank

J.C.A._3

But one other thing to consider....The MASS.

A 275 gal. oil tank has quite a mass, that will cool and heat slower than the outside temperature also. Being connected to the outside air with a vent will bring in the condensation along with it.

When the condensation has collected to the point that it forms droplets, they will fall to the bottom of the tank as the water is heavier than the fuel. As they fall through the fuel, they will bring some of the sulfer along with them.... Water and sulfer make a great combination called sulfuric acid, which rots the tank from the inside out.

In the state of Ma., the codes have been changed so that a new install is supposed to be pitched to the feed, which has moved from the first couple of inches at the front, to the bottom front, thereby making the water move into the filter when it does form.

As long as the code is met and the amount of sulfer allowed continues to drop, this will work wonders. As to the older style tanks we see... I always like to draw some fuel off of the bottom when changing a tank mount filter until it is running free of any moisture detected, then change the filter.

Outside tanks seem to see and feel this quicker than a tank mounted indoors, but we all know the answer to that one...
Chris

Jesse Markeveys

Condinsation In An Oil Tank (That is outdoors)

I was wondering how you actually get condinsation in an oil tank (That is outdoors). Does it happen because the steel sides of the tank conduct heat out of the air and the temp. of the side of the tank is below the dew point of the air? Or is it because of the humidity in the air that goes into the tank and eventually condenses and then falls to the bottom of the tank. I really am just wondering.
Thank you
Jesse

Brad White_9

A little of each

Air in nature always has some moisture in it. By virtue of that, air at any specific humidity has a saturation point or dew-point. This is found by cooling the air without adding or removing humidity, just dropping the temperature until the air can hold no more moisture.

In dry climates the dewpoint temperature is lower, in moist climates it is higher.

Any surface of a temperature below that point will have moisture condense upon it. Air in the tank, or rather moisture suspended in the air within the tank, will condense on the cold surfaces that are below the dewpoint of that air mass.

Water being heavier (more dense) than fuel oil, the water will sink to the bottom of the tank.

Constantin

Good points...

I'd like to add that the type of fuel delivery system may also make a difference. One-pipe oil-supply systems don't recirculate warm oil back into the tank the way two-pipe systems do. The warm oil will promote the formation of condensate.

One way to virtually eliminate condensation is via flexible fuel tanks that simply collapse as the fuel is drawn out. No air = no opportunity for the condensate to form on walls and the like. However, to the best of my knowledge, flexible fuel tanks are not permitted in home storage situations. On boats they can be quite common.

burnerman_2

water in fuel tank

i have been del. oil for 17 years and guess what i believe more gets in the from lazy drivers that do not tighten fill caps or the tank is under a leaking down spout or the plastic gauge vail is broken and to explain the 2 gallons of water we say condensation

Ron Schroeder

Or as in one night call

I find out that the 6 year old decided to play old delivery driver with the garden hose.

chapchap70_2

kids

This is why with one stop in particular, and others I know that have young children, I use the end of my nozzle to tighten the unifil cap after I make the delivery.

The easiest way to limit condensation is to keep your oil tank at least 1/2 full but not too full to allow for expansion in the summer. Having said that, properly pitched and filtered tanks as alluded to earlier in this thread would minimize the effect of condensation to not warrant this precaution.

Carl