new fuel line procedure

rgar98

I'm laying out about 40 feet of 3/8" polyethylene-coated fuel line. There are three 90 degree turns and one turn is in a different plane (up) and the line has to go behind a water heater and oil furnace (both are up against a wall) with very little room to maneuver.
What is the best way to approach this? I'm starting with a 50' coil of tubing. I have spring benders but how do you use a spring bender on a long run? Should I use 90 degree elbows, etc. which increase the possibility for leaks?
I just need a general description of how to approach the process.
Thanks for your help.
Richard

STEVEusaPA

By code you're not suppose to have any fittings, except at the tank (filter) and at the burner.
Don't forget your firomatics, and your OSV, power purge.
Easiest way to approach is have your oil burner tech do it.
Without a drawing it's hard to say how to do it.
But considering you are probably doing this yourself anyway, I generally start at one end (tank or burner), and unroll and bend as I go.

rgar98

Thanks Steve. How do you do the bends, with the coil, if you have to go around tight corners, etc?

Can I add a photo here? How?

rgar98

How do I add an image? Figured it out. Does this help?
Thanks.

ethicalpaul

Look for the "picture" icon on top of your message editing box when responding.

rgar98

Jamie Hall

Argh. Well, as @STEVEusaPA says, start at one end and go along to the other. If you are contemplating "tight" bends, you must use either a spring bender or a proper tubing bender. Assuming that you are using half inch pipe, if you are using a proper roll bender you can safely get down to about 3 inch radius. If you are using a spring bender, don't even think about less than a 5 inch radius. If you are trying to do it without a bender -- I'd personally limit myself to a 12 inch radius.

STEVEusaPA

Forget the spring bender.
Hard to guess the rest of the run, but basically run it like wire. Don't make the tight bends initially. Use large bend radius to get the tubing from one end to the other, and probably attach it at the fuel pump. Then work your way back to the tank, straightening the straight pieces and making your final bends all the way back to the tank, attaching the support clips along the way. Or it might go better from the tank.
One of those things that's easier to show than to explain.
I use a hand bender and at the tank and the pump where you need your expansion loops, I use a piece 3" or 4" pvc pipe to wrap around and make the loops.

rgar98

Thanks Steve. One more thing, please tell me about expansion loops.

Jamie Hall

What about expansion loops? If you have a pretty straight anything, as its temperature changes it is going to get longer or shorter. Some means must be provided to accommodate that change in length, and by far the simplest way to do that is to make sure that there is a set of bends -- or even sometimes just one bend -- between the ends which are rigidly fixed in place. The simplest to visualise is to consider a straight length of pipe, but now in the middle of it make a "U" bend -- 90 off to one side, over a bit, another 90 to parallel the original alignment, go along a bit, a 90 back towards the nice straight pipe, then rejoin the original alignment with another 90. There are simpler ways to do it...

rgar98

Thank you Jamie. Is the change in length you describe a problem with indoor fuel lines? Does the code require loops?
RG

Jamie Hall

The problem is much much less with indoor lines -- since they don't change temperature all that much. But the do change...

In practice, though, if there are a few bends in the line and it isn't particularly restrained, you shouldn't need to have to make any special allowance. The thing to avoid is a straight segment, restrained by fittings at both ends. I could contract enough to pull partly out of one of the fittings. But one 90 bend somewhere along the line and you should be fine.

I don't think the code speaks to that.

STEVEusaPA

Expansion loops required at the tank and at the burner

rgar98

Hello again,
Is there a rule of thumb about about when indoor oil tanks need to be replaced even if they have no apparent leaks or other problems? I think mine is about 45 years old! I've been living here for only one year, never had an oil-heated home before and learning as much as I can. I cut into the old oil line (I'm replacing it.) today and it was full of black sludge even though it ran well all last winter. The line I cut was about 2 feet from the tank and the filter is about 30 feet away near the furnace.
I'm eager to hear any and all suggestions.
Thanks.
Richard

stonebutson

The loops are to mitigate tank hum. I don't know if it works or not. in forty years I've never had a customer complain about tank hum (overhead lines nailed to the floor joists yes) but that's what Charles burkhart put out back in the day 

The safety line that your using is very forgiving when making bends. Just remember no fittings- it has to be a continuous shield from tank to burner. if a leak ever develops in the copper - it will leak out either end and be noticable - instead of leaking under the floor and heading for the water table. 
You really should have a licensed pro check your work when your done. It will be worth paying them for their time and years of knowledge. 

STEVEusaPA

stonebutson said:

The loops are to mitigate tank hum. I don't know if it works or not. in forty years...

Well you’ve been misinformed for 40 years. The loops are for expansion.

Big Ed_4

The old bellow Webster pumps were noted for tank hums ... Air trapped in the oil line was the cause .. The new pumps are not affected by it ...

EdTheHeaterMan

@stonebutson said:

stonebutson said:

The loops are to mitigate tank hum. I don't know if it works or not. in forty years I've never had a customer complain about tank hum . 

@STEVEusaPA commented on it.

@EdTheHeaterMan experienced it over 40 years ago. I changed a fuel pump on an oil burner with a basement tank bottom-feed oil filter at the tank (it was a model J pump back when it was called Sundstrand.) Two days later the customer called the company to say the tank was making a dull humming noise when the burner ran, ever since the new pump was installed.

My service manager was experienced and told me that some fuel pumps can cause a harmonic resonance that can be amplified by the tank. He said to go back and add a few feet of copper oil line to the existing fuel line by wrapping it around a coffee can to form a coil similar to that shown in the earlier picture. I did the loop thing and the noise went away.

Before I completed the repair, I had to tell the customer the reason the tank was humming is because it forgot the words.

Big Ed_4

Throwing a few nails in the oil line was another way out . To get out quick , shut off the tank valve to let the burner starve then turn it back on .... Working nights... Air trapped in the oil line caused tank hum . I remember a kit with a long plastic tube you slipped in the oil line with a spring on the end to hold it in place ... Back in the days with low pressure pumps ..... Hmmm check the pump pressure ..