outdoor aboveground oil tank -- sludge?

[cashug]

Hi,

I'd appreciate any help with this. I have a 275-gal aboveground outdoor oil tank. This heating season I've been having problems -- first the whistle on the tank apparently goes off when the tank is only half full so the oil company thought it was a full fill-up and the tank went dry. Since then it's been a headache -- within a couple of days the furnace sounded like it was throbbing (?). I initially thought the line was frozen or freezing (I had this happen my first winter -- I didn't know about the anti-gel you need to add to the fuel) but I had added the anti-gel when the tank was filled. The service tech blew whatever it was in the line back into the tank and changed the nozzle. Two days later, it happened again. and again. then fine until . . . the tank was next filled. same thing all over again. I've been told it was frozen water in the line or sludge from the bottom of the oil tank. One technician (I think I know all of them by first name basis now) said that condensation from the sun beating down on it during the summer leads to bacteria growing in the tank and that's the sludge on the bottom. I also read that condensation leads to corrosion and that's the sludge. so apparently when the tank gets filled the sludge gets stirred up then as it settles everything's ok. Does this sound right? I've been told I should replace the tank with a new one. Is this the only solution? I've seen these plastic enclosures for outside tanks -- would that reduce the condensation?
Thank you very much for your help!

[Al Gregory]

I hate Outside tanks. There are hundreds of them around here. A section of the city has a bunch of slab houses (Campennelli's) with the boiler in the kitchen and the tanks used to be in the garage and people moved them outside so they could make the garage into a room. If the tank is outside it should be on a concrete slab and the oil lines should come off the top of the tank. The bottom of the tank should be checked for water a cpl times a year. You should have a good oil filter inside the house near the burner so it cant freeze outside. They make an enclosure for outside tanks I think its called a Tank Mitten. If that old tank leaks or falls over your house could become worthless once DEP gets through with it. Get a new tank get it installed correctly and get it inspected.

[cashug]

Thank you for your quick reply. a couple more questions . . . my oil line is coming from the bottom so I guess that's one problem. who should check the tank for water? me or the oil company? and if it's me, how should I do that? It isn't on a concrete slab -- gravel. I believe the oil filter is near the burner inside the house. When you say inspected, do you mean by the building dept?
thanks!

[jrc2905]

I hate the thought of working on any system in a Campenelli.

Oil does not freeze, the wax in the oil does. The additive sould prevent that. Sounds like you have a water in the oil problem, may have been the result of condensation. Is there rust in the oil pump?

[johnsp]

Sounds also like each time they fill the tank they stir up the sludge in the tank. If the tank is over 20 yrs old I'd replace. You must have a good spin on filter in the house near the boiler. Some even put a regular General filter in front of that to trap the heavy stuff first. Very important to keep the tank filled during the summer, so there's no air space for condensation to form inside the tank.

[millerman]

A relatively new item on the market is the "floating suction line" by Oventrop USA contact at heatlines@comcast.net. The suction line floats at the top of the fuel line allowing only clean fuel to be pulled. Past Fuel oil news issues had a column in it giving pro's and cons. http://www.fueloilnews.com hope this helps

[joeoilman]

basement & outside aboveground tanks are required by code to draw from the bottom. (national fire code). tilt 1/4" per ft toward drain. firomatic valve ,flared lines. put filter inside house. ventalarm gauge, 2" fill, 2" vent (code) put it on a 3'x5'x4" pad & 12" legs. sturdy correct installation,sludge problem gone. (new tank)

[Al Gregory]

Originally posted by joeoilman
basement & outside aboveground tanks are required by code to draw from the bottom. (national fire code). tilt 1/4" per ft toward drain. firomatic valve ,flared lines. put filter inside house. ventalarm gauge, 2" fill, 2" vent (code) put it on a 3'x5'x4" pad & 12" legs. sturdy correct installation,sludge problem gone. (new tank)

Not in Massachusetts, Outside tanks have to draw off the top, They dont even want a valve on the bottom to check for water. They want the bottom pluged. Minimum size vent is 1 1/14 but not smaller than the fill size.

Around here oil tanks are inspected by the fire dept. The installer needs to file a permit. The floating suction line has been around a long time. A plastic tube that rides up and down on the tank gauge float. Maybe its improved now but the plastic tube would always crack and lose suction.

[indian]

You eastern techs have a lot to deal with burning oil. What is this about a whistle on an oil tank? Heavy oil generally doesn't create enough vapor pressure to require storage vessel safeties?

[casturbo]

An outside oil tank without any protection is troublesome to say the least. And the ones that don't have problems run poorly instead. It's a lose-lose situation. Any type of covering on the tank will work, whether it's expensive and pretty to look at or just plain cheezy in appearance, get something covering it. Don't go overboard and make filling the tank difficult though. Oil tanks come in different sizes and styles, maybe a "belly" tank will work if you have a crawl space somewhere.

[Al Gregory]

Originally posted by indian
You eastern techs have a lot to deal with burning oil. What is this about a whistle on an oil tank? Heavy oil generally doesn't create enough vapor pressure to require storage vessel safeties?

It sucks, everyday there is something new to deal with. Now they want us to replace oil lines when ever we make a change to a furnace or boiler. What makes it worse is everything is inspected by the fire dept that has no idea what they are looking at most of the time. We are basically the only trade that isnt inspected by people who work in our trade. Then we have plumbers complaining to their inspectors that oil guys are piping tankless coils though most of them couldnt pipe a boiler right if they tried. We have electricains complaining about us wiring boilers although we finally got permission to wire from the cieling down.

[jrc2905]

The Mass. code states you only need to replace unprotected oil lines or install an OSV valve on new or retro systems.

If I service an oil system with an unprotected under ground oil line, I give them an newspaper clipping about a leak that cost the homeowner $350,000.00 dollars, and I make them sign a slip that says they were informed that they have a been informed about their unprotected oil line. Most homeowner’s insurance policies now only pay the neighbors clean up costs. Most business liability insurance no longer covers oil spills.

I spoke to my local inspectors about this and because they want to encourage the replacement of unprotected oil lines they told me that I could do the work without a permit, they would consider it a repair.

[Al Gregory]

Many towns want nothing to do with OSV valves anymore. I guess the people that were putting nickles under the cap to hold them open ruined it for the rest of us. If you swap a burner, a tank, or a boiler you need a new line. I like the idea of having them sign a piece of paper. I wonder if that would hold up in court though.