New oil tank with new lines being run

Roho

Replacing the two 3/8 lines to a furnace with 1/2. Do I need to replace the 3/8 line after the filter that goes to the pump and will it hurt to leave the 3/8 return line to where it will be connected to the 1/2 new return line to the take .I would be 1/2 pipe to filter then 3/8 going to the pump and the 3/8 coming out to a 1/2 return line .

STEVEusaPA

Why do you need 1/2"? I wouldn't switch to 1/2" unless there was a proven need.
You should replace them all. They need to be the same size, and continuous, no extra unions/fittings. And of course it needs to be done by code.
But if you switch back to a single pipe system, you'll need to remove the bypass plug in the fuel unit or you will destroy it.

EdTheHeaterMan

Regardless of the reason for the replacement, if you install 1/2" fuel lines from the tank to the burner room, the restriction of 1/2" piping will be less than that of 3/8" piping allowing for some slight flow capacity increase reducing Vacuum created by the fuel pump on the supply line. That said, the 3/8" tubing from the filter to the pump will only deliver the amount of fuel that 3/8" tubing can deliver. Since that is currently working, then there is no problem with what you propose to do.

Think of it this way. The water service into your house might be 3/4" or 1". If you only have on toilet connected to the service, the toiler will work fine. You just have overkill on the water service. The water will flow slowly thru the larger service line, the water will flow faster thru the 3/8" branch valve and tube to the toilet tank. Speed of flow will change but the GPM will stay the same.

If in the future you have a need to add more than just a toilet to your service, you have extra capacity.

So 1/2" is ok but 3/8" is less expensive. Also, what is the total length of the copper from the tank to the burner, and what is the total length of the return from the burner to the tank?

Same questions as @STEVEusaPA Why change? and Why 1/2"?

Roho

The tank is outside and about 8 feet of pipe will be outside. I was thinking that the half inch pipe would not gel as fast as a 3/8 inch pipe.

Roho

Also the old pipe is buried underground.The new pipe will be above ground. We are using #2 fuel oil now. I may switch over to the #1 fuel oil when it gets below 32 degrees Or a blend of 50/50 of the two. I want to avoid gelling if anyway possible

SuperTech

I would imagine that the additional oil content in the 1/2" line would be more prone to gelling. I would avoid this scenario by using a single 3/8" line to a tiger loop ultra at the boiler or furnace. Use an additive with each fill up of the tank.

woodrow

Hopefully using a roth tank. outdoor oil tank is looking for problems with moisture .maybe a conversion burner to propane might be a better option

EdTheHeaterMan

@Roho, your logic is sound. At the lower temperature, the oil will become more viscous. The larger diameter will have less friction on the same volume of fuel. the only change is the fuel line. the fuel pump is going to move the same gallon per minute through the larger diameter tube.

Now it is more clear as to the purpose of the change. You have experienced burner failure at low temperature. The reason has been diagnosed as gelling fuel. This may or may not be accurate. You May have some water in the bottom of the tank. The source and quantity of that water are numerous. So there are several things to consider.

With a new tank, DO NOT PUMP ANY OF THE FUEL FROM THE OLD TANK TO THE NEW TANK. you may inadvertently move your problem from the old tank to the new tank.

When installing fuel lines from the outdoor tank to the indoor tank, do not create a trap in the copper line. Be sure the fuel line is pitched 1/4" per ft or greater in the direction of the house until the tubing is inside the home or basement or crawl space.
As indicated in this illustration the smallest amount of water in a fuel line can settle in a trapped fuel line since water is heavier than fuel. In extremely cold weather, this can freeze during a burner off cycle when the fuel is stagnant in the fuel line.

You can accumulate a tablespoon of condensation in a tank in less than one year.

Consider a tiger loop or other fuel deaerator. This will reduce the flow of the fuel thru the fuel lined to that of the firing rate of the burner. A two-pipe fuel system will have increased fuel flow to the rate equal to the pump gear set capacity. This can be as much as 17 to 30 gallons per hour (GPH) depending upon your fuel pump.

(Some "experts" on this site will contest this claim but they have not done the testing or read the technical literature on YOUR fuel pump. I have actually operated a fuel pump from a 5-gallon bucket with the return in a different 5-gallon bucket. It took less than 15 minutes to drain the bucket of exactly 4 gallons of fuel. My Beckett clean-cut pump is rated at a 17 GPH gear set capacity and a firing rate of up to 3 GPH. I was actually firing .60 GPH.)

Finally, Use new fuel oil from a reputable dealer. Don't take oil from any old fuel tanks (including yours as stated above).

EdTheHeaterMan

Follow up:
I have indicated 3 things you should consider for outdoor above-ground tanks that I have practiced with great success. You may not find those specifications anywhere else but here. This has been tried and tested over time with over 200 new oil tank installations and numerous fuel line repairs over 30 years of service to South Jersey customers.
There are many other considerations in replacing your fuel tank
here are some of them I found when I Googled: "home heating oil tank replacement best practices"

https://www.santaenergy.com/blog/when-to-replace-oil-tank/

https://www.tanksure.com/Best_Practices.pdf

https://inspectapedia.com/oiltanks/Oil-Tank-Replacement-Procedure.php

Roho

Thanks

Jamie Hall

Somewhere up there gelling was mentioned as a concern. Untreated #2 fuel oil shouldn't gell until you get down to around 18 Fahrenheit. Pour point additives should be used if it is going to get colder than that -- but in general, if you buy your fuel from a reputable dealer and they will have added them already (you can always ask...). One place where you can get in trouble even so is if you have fuel delivered in warm weather -- summer or fall -- and don't use it before the first good cold snap, you can have a problem. The ungel point is higher, and if the fuel does gell you may have to wait for it to warm up to flow again.

A mix of kerosene will have a lower gel point, and usually low enough.

Fuel filters in cold locations can clog at somewhat higher temperatures, either from wax crystals or ice crystals. They should not be in a cold location.

EBEBRATT-Ed

Well, maybe we should pipe it two pipe and use a return line oil heater to warm up the tank like we used to do on #6 oil which had to be warmer than 90-100 degrees to pump it

Roho

It will be a two line install. With an double walled tank outside. The filter will be located inside.Using coated lines.What's a good insulator for the lines. I plan on going with a mix of #2 and #1 to be less concerned with gelling

SuperTech

I've seen UV resistant Armaflex insulation used on oil lines, but I've always questioned the effectiveness of insulation on an outdoor oil line from an outdoor tank. Unless you are putting heat tape on the line before you insulate it I don't think it will do anything. Perhaps @EdTheHeaterMan or @STEVEusaPA will have an opinion on the matter. They are both very knowledgeable on oil heating, I value the knowledge they share on here.

It sounds like you are on the right track by using the Roth tank instead of a single wall. Oil filter indoors is a must. Consider installing a spin on filter such as a Garber if you aren't using one currently.

STEVEusaPA

Depends on where you're located. Heat tape with a thermostat is a good idea. So is a heated dip tube. The main thing is keeping water out, and using additives. Especially if you are using a bio mix. The cloud and pour points are higher with bio heat, and moisture is the problem.
If you're wrapping the oil line with heat tape, I'd put the UV resistant Armaflex around it too. I don't quite see the benefit of just insulation, but then again, I'm talking about my area.
I can tell you in the Philly area (last 'winter' not withstanding), I rarely had a freeze up. That's with a couple nights getting down to 0° with a high of 15°.
Again, depending on your area, I wouldn't bother with Kero either. Unless you always use a 25% kero mix and tune the burner to that fuel. Additives are way cheaper than kero, unless you are in an area where companies regularly blend this. There's virtually no Kero in the Philly terminals.
If all your flares are good, you won't need nor should you want a Tiger Loop, unless you need to warm up your oil, then I'd recommend a Tiger Loop, and on the return from the pump back to the loop, I'd pipe in maybe a 2"X 2' piece of steel pipe, with the proper fittings. That extra oil sitting by the heater will warm the oil up some, and you'll have cleaner combustion.
Even better is a nozzle line heater.
Best is an indoor tank.
Don't forget, firomatic right after where the oil line enters the house, double filter(General then spin-on), OSV (if gravity) then firomatic at the burner.

EdTheHeaterMan

I could never understand why customers want the fuel line insulated. Insulation does not create heat. Insulation slows the transfer of heat. That said, your refrigerator is insulated to keep the stuff inside it cold. Insulating the fuel line will make sure the sun's heat will not warm up the fuel line during the day.
Now if you are heating the line, then you will want to keep that heat in with insulation. I never recommended heat tape on a fuel pipe. Did not want the liability of a heat tape malfunction causing a fire. Rare occurrence but one time is one too many.

Heating the return oil to warm up the tank does not seem practical. If it was a good efficient idea, then everybody with an outside tank would already be using one. I don't believe I have seen any Return Line Oil Tank Heaters on the market. How many BTUs of heat are needed to keep 200 gallons of oil above 40° when it is 10° outside? (Rhetorical... Sarcasm)

I would spend the extra on a fuel deaerator and forget the return line to the tank. My preference. Not everyone agrees.

Big Ed_4

I agree one pipe tiger loop and no traps to freeze if I had to deal with a outside top feed tank .