Tank Slope for Outdoor Tank

BinDerSmokDat

I've heard about two different schools of thought when bottom feeding off an outdoor oval vertical tank...

1) Slope tank away from the outlet to AVOID picking up water and sludge...

2) Slope tank towards the outlet, use additives and let the filter deal with the crud...

My current thinking is to do 1).
In the winter I use a multi-fuel salamander to heat my detached pole barn that can run on kerosene/diesel/#2.
I also use a drum-style manual crank fuel pump in the winter to pump fuel from my oil tank to a fuel can.
I'd designate the bung over the "sludge/water" end for my transfer pump and add a rubber hose extension, so that I'm pumping out any water and crud from the very bottom into my fuel can.
Then I let that can sit and use a siphon to take fuel off the top for the garage salamander.
Any water and crud left in the bottom would eventually go in my waste oil disposal jug.

This way the tank slopes away from the feed AND I'm periodically removing water and sludge as it accumulates and hopefully before a lot of algae and crud build up.

Thoughts?

STEVEusaPA

Manufacturer and every knowledgeable person in the world recommends sloping 1/4" per foot toward drain. Let the filter(s) do their job.
Buy 2 9" legs and 2 10" legs and you'll have your slope on level ground.

EBEBRATT-Ed

I agree with @STEVEusaPA

Why collect sludge in a tank? It will get sludge eventually anyhow. Slope towards the outlet

Jellis

Slope towards the drain, change your filter yearly and you should never have an issue with your fuel.

Slope it away from the drain, you may save a few filters... But guarantee system failure, plugged oil lines and tank that requires treatment and possible pump out once the sludge builds up enough to reach the drain.

Without a doubt the proper way is install with the tank sloping towards the drain.

Big Ed_4

Depends on where you live ,some states want you to top feed . Their fear is freezing , breakage and leaking out oil . I think it's dumb thinking. I disagree . Let me explain ...Oil will float on water . Water will freeze and oil would thicken. Where water and oil meet an algae with thrive . The algae eats the oil and it's waste product is sludge , you know the crap that plugs up filters and nozzles .The fuel you buy does not come with sludge . Sludge is produced with the right environment in a poorly designed tank..Also on another point the algae can not digest the sulfur in the oil it eats and it's waste (sludge) is sulfuric acid base which can eat out the bottom of the tank .

The key for trouble free system is to kill the eviroment simply drain away the water from freezing.. I would recommend to set up an tank with high enough legs , 1" higher legs on the far side from the bottom feed ball valve . Pipe the supply tubing on a constant down hill to the inside of the house or basement to an oil filter away from the cold.. The filter will catch and hold the normal small amounts of water and gets dumped out with a filter change .. ... Keep you warm on them bitter cold nights

BinDerSmokDat

Well the old tank DID slope towards the feed for 20+ year with only one line blockage due to ice/gel in all that time. I should probably stop overthinking things.

richkenny7

I have a problem with water freezing in my line. I thought that if I sloped the tank away from the drain, the water wouldn’t enter the line. After reading your responses, I realize the water and sludge will just build up in the tank. I am trying to solve my line freezing issues. I know it’s water freezing because the problem happens around 22 degrees.. too warm for oil to gel. I opened my line once and found some ice chunks. 

I’m out there with the heat gun hitting the few feet of line that is exposed every time it gets cold!

STEVEusaPA

Yeah re-slope, then start draining into a bucket until the water is gone.
Then, put in some fuel treatment that disperses water and lowers the pour point.
Keep in mind, if you're using bio, that does freeze like water, so you should treat the tank with every fill up, 1/2 bottle after you get rid of all the initial water.
Some people wrap heat tape around the oil line at the tank, leave it plugged in and controlled by a thermostat. But I think if you eliminate the water and treat the tank, you should be fine. Of course if you're in a below zero type of climate, more extreme measure may be needed.

EdTheHeaterMan

I have installed top feeds many times in order to resolve the "Frozen Fuel Line" issue. My optimum top fuel feed is to slope the tank in the direction of the bottom drain. Install a 1/2" street 90° and a full port ball valve in the bottom tap I add a 1/2" cap for safety. Then I install the top feed at the higher end of the tank about 2" to 3" from the bottom, which will draw all the way down to 4" from the bottom of the low end of the tank. That leaves only about 15 gallons of bottom oil that you can't use. Any accumulated foreign tank bottom deposits will accumulate at the low end near the drain valve.

Every summer during the annual maintenance I open the 1/2" ball valve and let out any tank bottom deposits and condensation. It turns out that if this is done annually, there is very little "JUNK" that comes out. this is verification that my plan works. The key is maintenance. Now that I'm retired and someone else is servicing my customers, that may not happen anymore.

Maybe that is a flaw in my design.

Respectfully submitted,
Mr.Ed

PS
I had an illustration I used to use (can't find it anymore) that shows how a tablespoon of water (about a month's worth of condensation in a 1/4 full 275 tank) could block a fuel line that has a slight uphill bend outside, before entering the basement or crawlspace. The key is: if using the bottom feed on the tank, make sure the fuel line has a continual downslope until the fuel line is in a space that is protected from the freezing temperature.

EdTheHeaterMan

I found my illustration about the frozen fuel line from 1 tbsp. here
https://forum.heatinghelp.com/discussion/comment/1607985#Comment_1607985

HVACNUT

EdTheHeaterMan said:

I have installed top feeds many times in order to resolve the "Frozen Fuel Line" issue. My optimum top fuel feed is to slope the tank in the direction of the bottom drain. Install a 1/2" street 90° and a full port ball valve in the bottom tap I add a 1/2" cap for safety. Then I install the top feed at the higher end of the tank about 2" to 3" from the bottom, which will draw all the way down to 4" from the bottom of the low end of the tank. That leaves only about 15 gallons of bottom oil that you can't use. Any accumulated foreign tank bottom deposits will accumulate at the low end near the drain valve. Every summer during the annual maintenance I open the 1/2" ball valve and let out any tank bottom deposits and condensation. It turns out that if this is done annually, there is very little "JUNK" that comes out. this is verification that my plan works. The key is maintenance. Now that I'm retired and someone else is servicing my customers, that may not happen anymore. Maybe that is a flaw in my design. Respectfully submitted, Mr.Ed PS I had an illustration I used to use (can't find it anymore) that shows how a tablespoon of water (about a month's worth of condensation in a 1/4 full 275 tank) could block a fuel line that has a slight uphill bend outside, before entering the basement or crawlspace. The key is: if using the bottom feed on the tank, make sure the fuel line has a continual downslope until the fuel line is in a space that is protected from the freezing temperature.

You invented that? Thank you. 

Dave T_2

Here in MA, for an outside oil tank, the bottom outlet is plugged and the supply line installed in the top and slope to the conditioned space so as to avoid any trap where water may accumulate and freeze.
Installing a pipe and valve at bottom of tank may allow water to accumulate in pipe, freeze, split the pipe, and leak the tank contents when it thaws.