Copper fuel line sizing & fuel oil additives

belham

Here is my home setup:



If you've seen my other thread recently (apologize for its length), you'll know currently my home fuel oil-burner system is suffering from nozzle "after-drip"...... that can be pinpointed to either incoming-suction copper line narrowing (from the fuel oil slowly gunking up the sides of the inner copper pipe over 20 yrs) and/or "air" getting in the lines from the tank to the Afriso filter. Or possibly both. My burner/boiler unit still runs good, but you can tell-----because of the -0.4 to -0.5 vacuum it is pulling on the suction line during a burner run----that something needs fixing or replaced, fairly soon. And that 'something' would be the copper lines coming into the house.

So, one way or another, I am going to be laying new sheathed copper pipe (hopefully when the weather turns warmer here in 3-4 months) or, the dreaded option, maybe now. There's also the option of installing the new Afriso Flocop Tigerloop device I bought, but that means messing with the current 20+ year old sheathed copper 2-lines currently coming into the house. Basically, if I do this, I'd be going from my current 2 line setup to a one-line, and (I've no room to screw anything up as there's no service loop and/or extra copper length to play with. This is true for both the suction line coming in, and/or if I decide to use the return line as my "new" suction line).

Ok, my questions:

1) My current suction/return copper lines are 12 mm (near 1/2"). When I lay new sheathed copper, given the distances in my pic from burner to undergound tank, and the 3-4' lift, would you guys go with the same diameter tubing, or would you go down to 10 mm (3/8") or possibly down to 8 mm (1/4")?? I always thought, to a certain extent, that having a bigger diameter pipe was a good thing. But what confuses me is the new Afriso TL device (and all devices I researched) provide only compression fittings*** for incoming-suction line sizes of 10mm (3/8") and 8mm (1/4"). What happened to 12mm or 1/2" tubing? Is it now consider not a good thing?? My current old Afriso fuel filter on the side of the burner/boiler (see pic) is 12mm, so....?

***Yes, I realize the affinity for "flared" fittings in North America, but in Europe, they have developed 'different' compression fittings (pic of them in other thread) that are considered better, longer lasting and idiot (installing) proof. And those are what is spec'd here, for home heating installs.

2) Fuel oil additives - do they help or not? I realize this might be voodoo science and cause serious disagreements, but does anyone here regularly (say at every fill up or once a year) add an additive to their tank? I have easy access to my in-ground tank, so adding something is no problem. I had always been under the impression that in today's day and age, fuel oil & any gasoline-type have already added to them various additives---especially in the over-regulated European (German-French) markets. Still, would adding something to my 800 gal tank help at every fuel up, or maybe help in the future to keep my copper lines not-so-gunked up over time (like is happening now)?? One old guy I met in my neighborhood, he dumps about a pint of "white vinegar" once a year to his underground fuel oil tank. I was like: WHAT? You dump VINEGAR in there?!!


Thank you for any advice, hint and/or tips.

Brian26

I have used Hercules Sludge treat many times and it seems to work based on filter changes. Do you have Kerosene available? I have read that adding a few gallons of it will clean out the system.
https://www.oatey.com/2377232/Product/Hercules-Sludge-Treat

EBEBRATT-Ed

I would use 1/2" od from the tank to inside the building, then use 1/2 or 3/8 inside. Oil treatment depends...your not getting any sludge so why bother?

With 4' of lift and a buried tank it would stay 2 pipe if I was doing it and it would have a two stage pump

Brian26

Are underground tanks still allowed even in Germany? I have read their regulations are quite strict and perhaps they are grandfathered in if you have one?

Here in Connecticut if you have an underground tank you essentially cant sell your house until its dug up and replaced. I believe all of New England and NJ requires this?

Big Ed_4

You would size fuel lines to the distance and volume of oil traveling through them . ... With the tiger loop the volume would be the firing rate input .. If there is an suction leak the oil in the tiger loop will be foamy when the burner runs...

. I would drop it down to three eights for the ease if using copper .. I would also use the flexible braded lines instead of copper ..

You are being careful with the connection because you have just an short piece coming out of the floor to use .Compression fitting are rated for an one time use .. They also need an solid piece of malleable copper .. Old oil lines get thin and brittle .. If you have a 1/2" flair union at the floor and worried about the flair .. Disconnect the burner side flair and instal an 3/8" adepter , the adepter comes with copper flair insert . Dont forget that ..

As. far as additives some do work . You want one thats kills the algae and breaks down and neutralizes its poop ..


Any room for an new inside tank ? Properly installed all your problems are solved ....

belham

@Brian. Kerosene? Jeez, I don't know, would have to check. I haven't thought about kerosene since I was a kid man, many decades ago in the Midwest & my Dad had a portable (Sears or Montgomery Ward) kerosene burner to help heat our basement in the winter. Also, far as I know, in-ground are grandfathered in, but they prefer everyone (across Germany, Luxembourg, Netherlands, Belgium & France) to go to natural gas. Problem is, they still don't have natural gas piped to everywhere.

@Ed, yeah, haven't seen sludge or junk of any kind in my filters (or overall system) for years. But I realize that may be me since I do clean the mesh screens twice a year in straight gasoline and put them back in. Keeps gnawing at the back of my head how I am having such bad vacuum readings now---showing what I guess is obvious sludge in the lines (there's no kinks and/or bends in the lines other than going in at the top of the tank), yet I've never seen sludge and/or residue of any significance anywhere in the system. Weird.
Re: the pipe: hmmm, 1/2" or 12mm, eh? 1/2" (12mm) sheathed, grooved copper for oil/gas is still widely sold, so I can easily go that route. Probably will now.

Regarding a two stage pump: what does a 2-stage do in comparison to a one? Also, can I just (forgive the ignorance here) slap a 2-stage pump on my system without doing anything other than replacing the pump? Or does it all have to be re-wired and the burner specially setup to specifically handle 2-stage? (hey, wanted to tell ya before I forget, found out through slogging thru old manuals that my burner does have a pre-stage sequence but no post-stage purge).

Thanks for the feedback guys.

Big Ed_4

An two stage pump is used for high resistance two pipe systems , as the vacuum increases gasses start pulling out of the oil , The second stage blows off the foam into the return .. Too much gas and the pump cavities

Using the scale of inches .. The gasses start to pull out around 5" inHg and burner starts dropping after 12" inHg

At rest the vacuum would be the hight of the burner from the level of oil.. and should hold if no leaks.When the system runs under two pipe , the vacuum is the total of the rated volume of the pump x resistance + hight .... With the Tiger Loop it would be firing rate x resistance + hight

If you don't see any sludge then your oil already come with and additive ..

Western Europe you are from ? What are you reading vacuum in mbar ?

belham

Benelux region, right on the German-Belgium border (close to Luxembourg).

I've been reading on Google & came across this from Suntec (which are pumps used on Weishaupts, along with Danfoss pumps):

"Why a Two Stage Pump?
Reprinted from Suntec Techincal Bulletin

Since any Suntec single stage fuel pump can provide more than 20 inches of mercury vacuum, you might wonder why anyone would want to manufacture a two-stage pump.
The answer is that a two-stage pump satisfies the special need to pump fuel oil which has certain characteristics that defy efficient pumping by single stage pumps.
Fuel oil starts to break up, or "boil" at vacuum levels as low as 10 inches of mercury. When that happens, foamy oil collects within the pump.
A single stage pump will send the foam directly to the nozzle, causing unstable atomization. The result will be for the burner to burn dirty and reduce the effectiveness of the furnace's heat exchanger.
Also when the burner shuts down, the bubbles in the nozzle expand out of the nozzle, causing after burn, smoke and soot. Oil may even run down the nozzle line and drip on the pump shaft, making it look like the pump is leaking.
One way to correct this problem is to use a two-stage pump incorporating two gearsets with carefully designed porting geometry.
The foam created by operating under high vacuum collects in the highest portion of the inside and around the internal perimeter of a pump. By design, the first stage gearset not only brings the oil into the pump, but also returns any foam back to the tank.
Also the second stage gearset inlet ports are located so that this gearset is supplied clear oil at vacuum levels up to 17 inches of mercury.
However, good practice suggests that to accommodate all varieties of #1 and #2 fuel oils and to effectively compensate for the gradual reduction of line I.D. caused by build-up on the inner walls, vacuum should be limited to 17 inches of mercury on initial installations.'


Gotta say, I am more than intrigued now. Danfoss sells 2-stage pumps that fit my boiler, but I have to also wire in their controller. Trying to see if I can understand how to do this & how it all would work, because every time I re-read what Suntec (and we can substitute Danfoss in there too) said above, all I can think is: problems solved, forever

Big Ed_4

I would go with the tiger loop. , what if the return line is leaking ?

STEVEusaPA

I would do 1 pipe, larger size, tiger loop.
First I would take a 5 gal. bucket of clean oil, short pipe to the burner, bleed and run. See if you're still getting your after drip.
As far as additives, 2 things:
1. Have a sample of your oil taken at the bottom of the tank and up higher, checked to see what's going on if anything in your tank.
I also hear in Europe, it pretty common to have companies that clean the tank. At the very least you could hire them to bring over a fuel polisher.
2. Once you figure out if you need an additive, only use one brand. Don't try different brands 'just to see'.
Regarding the oil de-aerators, I recently saw some I & O manuals on new condensing oil boilers in Europe. One thing I saw which struck me as very odd, was that the oil de-aerators was spec'd to be installed outside the house. Seems to defeat the purpose of the benefits.

belham

@Ed, crap, totally forgot to answer your "mbar' question:

During burner running, it reads a steady -0.5bar (-500 mbar).

When burner is off, it reads near -0.1 bar (-100 mbar). (Am really confused why the vacuum gauge reads anything on the suction line when the burner is off).


So I've a difference of -0.4 bar (-400 mbar) between "on" and "off".

SuperTech

I agree with Steve and Big Ed. Install the Tiger Loop. There's no down side to it. It would definitely solve your problems. And do the two stage pump. It wouldn't hurt anything.

EBEBRATT-Ed

@belham , a 1 stage pump has 1 set of gears that pulls the oil from the tank and pressurizes it to the nozzle. they are used for gravity feed or low lift conditions.

A two stage pump has 2 sets of gears. 1 stage pulls oil from the tank 2 stage pressurizes it to the nozzle. Used on higher lift situations.

Where you have about 4' of lift per your drawing either pump should work 2 stage preferred. No wiring changes just swap the pump nothing else changes

newagedawn

the pump is dead, the seal is gone,change the pump and watch that drip go bye bye

newagedawn

a standard suntec 3450 will handle that set up

belham

newagedawn,

Lol, can't be the pump when a person has 2 new extras lying around & they all do the same thing. Appreciate the effort though