3/8 Flexible Copper Fuel Line Replacement

Old 09-15-02, 10:05 AM
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Question 3/8 Flexible Copper Fuel Line Replacement

On one side of my basement, I have a 275 gallon fuel oil tank that feeds both my oil fired hot water heater and my oil burner on my furnace for my forced air heating system. The water heater and furnace are on the other side of the basement. The 3/8 flexible copper line spans the perimeter of the basewment along the intersection of the floor and wall and is approximately 43 feet in length. The basement floor is concrete and the walls are concrete block and both the floor and walls have been painted with a latex paint made for concrete. The basement is very dry.

I am concerned because at various places along the way, the copper line has a thick build-up of aqua or blueish green corrosion all around it.

My question is, is this corrosion actually eating into the copper line and will it eventually cause a leak, or is this corrosion simply some sort of reaction that will not cause detrimental effects to the line? Should the line be replaced or is this nothing to worry about? Is there something made especially for cleaning this corrosion off of the line? If I replace the line should I use compression fittings or flare the ends of the line and use flared fittings? If flaring is the way to go, will a single flare be adequate or is a double flare necessary?

Thanks for any and all responses.
Old 09-15-02, 01:55 PM
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the blue/gray

is called "patina" by roofers who use copper in their trade, i call it corrosion. if the buildup is thick, replace the line, it cannot hurt, and will be dangerous to your family should it leak. i have not worked on fuel oil for years, but my opinion is that a single flare (not sure what you mean by double flare) connection at each joint should be sufficient. the fuel oil is not under high pressure, so i would think compression would possibly be overkill. other pros on this site who work with this every day can give you better advice, but in my book, a couple hundred bucks is worth the peace of mind.
Old 09-15-02, 08:47 PM
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I'm inclined to think it's corrosion. When you say "flexible line" I think you mean soft [annealed] tubing? Single flare connections are fine. Double flares are used on brake lines for cars. BTW- if you find that you need to connect any tubing together with sweat type joints, they have to be brazed and not soldered. The fire protection code for fuel oil requires it. Also, use copper or plastic straps.

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