Single line oil tank bushing help - top of tank

PNJ

I have a single line system, there is no return line. I am replacing my very old underground oil tank with a one year old, above ground outdoor tank in that's currently bottom fitted (I will replace it's bottom fuel fitting with a plug).

So I need to change this new(er) tank to feed from the top, since it is an outside tank. I have done exhaustive research into everything I need (alarm, new jacketed fuel line, using flared fittings, new firomatic valve before my filter, etc.) but I can't find the bushing I need for a single line system. Everything I see is for a two line system - which I don't have.

Can someone point me in the right direction to what the correct bushing is I need for the top of the tank, and the correct fitting to connect to a new 3/8 in. fuel line (only a small portion of the line will be outside, most will be attached to the floor joists in a half-basement: Is a jacketed line still recommended?)

Also, should the fuel line run continuously through this top single line bushing to 4" from the tank bottom, or should their be a separate pipe inside the tank connected to the bushing like this shows:

https://inspectapedia.com/oiltanks/Oil-Tank-Replacement-152-DJF-5MacCc.jpg

Thanks

pecmsg

Replacing an old unground tank

replace it!

PNJ

As I said I am replacing it with an above ground tank, that's the purpose of my question here. I'm not replacing the furnace, and it's a single line system. So I need the right connection to the top of the new tank to the fuel line but I can't find a single line bushing. How do I attach the fuel line to the new top of tank?

pecmsg

Outside tanks have a bottom supply line!

STEVEusaPA

Why do you think a top feed is better? Bottom feed, pitched toward the outlet is the best setup for a steel tank. Keeps water and crap from accumulating in the bottom of the tank.

PNJ

@pecmsg @STEVEusaPA This is what's hanging me up, it appears to be the right way but neither explain exactly why

https://youtu.be/Gy_47EmYPN4?t=1141
NORA Video 8, How to Install Steel Aboveground Tanks (Residential)

and
'outside oil tanks... outside oil line should be connected to the top and insulated where it enters the building'

PNJ

I don't know why they say outside tanks should be top fed. But I thought by drawing from the top, and from 4 inches off the bottome of the tank, you would reduce the chance of any water or sludge from entering your system. Wouldn't feeding from the bottom draw anything down there drectly into the fuel line?

The tank I'm replacing it with is a year old and has a little dried sludge on the bottom, and it is a bottom setup. What is the best way to clean it out?

EdTheHeaterMan

https://www.supplyhouse.com/Beckett-14468-2-NPT-x-3-8-x-3-8-3-Way-Tap-Duplex-Tank-Bushing-w-Male-Compression-Fitting?_br_psugg_q=duplex+tank+bushing

Plug the opening you don't use

PNJ

I live in NJ, it gets cold. So the apparent purpose of top feeding is to help prevent freezing. Here is a different post from this forum:

Dave T_2 said:

Here in MA, for an outside oil tank, the bottom outlet is plugged and the supply line installed in the top and slope to the conditioned space so as to avoid any trap where water may accumulate and freeze.
Installing a pipe and valve at bottom of tank may allow water to accumulate in pipe, freeze, split the pipe, and leak the tank contents when it thaws.

So when it's 2 degrees here I'm thinking top fed is better for outside tanks?

PNJ

Thanks @EdTheHeaterMan. Your link includes compression fittings, they are ok to use instead of flared? Everything I see says to never use any compression fittings.

EdTheHeaterMan

If you have a used tank and you want to remove the tank bottom deposits, I have used my fuel transfer pump with a garden hose nozzle connected to the end of the discharge hose. T then open the bottom tapping to let the oil flow out of the bottom of the tank as a drain. By connecting a hose to the bottom tapping or by placing the tank over a large basin to collect the oil that drains out, I then squirt oil at the bottom of the tank by drawing clean fuel from a 5 gallon pail. The clean oil tank bottom with pressure from the pump pointed at the tank bottom thru on of the 4 top openings, as you would use a garden hose to clean the driveway with water from a hose nozzle

Dispose of the dirty oil properly by recycling it at the local waste oil disposal site of with someone that operates a waste oil burner.

EBEBRATT-Ed

You buy a duplex 2 x 1/2x1/2 or 2 x 3/x3/8 tank bushing. One tapping comes with a compression fitting your oil line will slide through. The other tapping just install a plug as @EdTheHeaterMan said

EdTheHeaterMan

PNJ said:

Thanks @EdTheHeaterMan. Your link includes compression fittings, they are ok to use instead of flared? Everything I see says to never use any compression fittings.

The compression fittings are not to seal the oil line as a leak free fitting. the compression fittings are to hold the fuel line in place so the fuel line does not move up or down inside the tank.

The best practice for that fitting is to remove about 48" of the plastic cover from the fuel line. Then slide the compression nut over the fuel line until you reach the plastic covering, followed by the compression ring, then followed by the compression fitting. Those fittings are designed without a stop for the copper to be able to slide thru. Once the fitting is 48” past the end of the tube, straighten the tubing and insert the tubing into the tank thru the ⅜” pipe tap opening. With the copper on the bottom of the tank, slide the compression fitting into the ⅜” threads and tighten the fitting. Next slide the compression ring and the compression nut on the fitting but do not tighten the compression nut.

Now with the fuel line on the bottom of the tank, raise the fuel line up about 2-½” to 3-½” off the tank floor. Now tighten the compression nut to hold the fuel line in place. Not too tight, just tight enough to hold the tubing in place. By using this method, you will have one piece of tubing with no fittings at the top that can leak air into the fuel line that can cause a break in the siphon line and cause air to create a no heat situation because the fuel pump loses its prime.

This is an old trick I learned over 45 years ago. The tube is seamless, one piece, with no fittings, from inside the bottom of the tank to the top of the tank and then back down to below the tank. Once you prime the fuel line, that will act as a siphon and you will have trouble free operation.

PNJ

EdTheHeaterMan said:

This is an old trick I learned over 45 years ago. The tube is seamless, one piece, with no fittings, from inside the bottom of the tank to the top of the tank and then back down to below the tank. Once you prime the fuel line, that will act as a siphon and you will have trouble free operation.

That's exactly what I was hoping for, how to get the line seamless into the tank. That's about how long ago it was I heard of it but I couldn't find a way to do it because I wasn't sure about using compression fittings. Is there a minimum length of line to leave straight, after/above the compression fitting, before I bend the line down - so I don't disrupt the airtight fitting? I only want to do this once.

EdTheHeaterMan

Is there a minimum length of line to leave straight, after/above the compression fitting, before I bend the line down - so I don't disrupt the airtight fitting? I only want to do this once.

No. The compression fitting is not meant to be air tight. Just to hold the "air tight" tube with no seam or joint between the bottom of the inside of the tank and the other end of the tubing (hopefully inside the home and below the bottom of the tank.)

For appearance sake and serviceability, I would start the bend about 1 or 2 inches above the compression fitting. But if your situation calls for it, you can go as high as you need to before turning back down to the oil burner or oil filter or what ever the next fitting is. I like to use a valve right inside the building to facilitate filter replacement and other service needs. You want to be able to shut off the siphon flow from the tank for service.

PNJ

Thank you @EdTheHeaterMan. It's all coming together for me now, but

EdTheHeaterMan said:

... between the bottom of the inside of the tank and the other end of the tubing (hopefully inside the home and below the bottom of the tank.)

Current setup: underground tank is about 20 ft. from the furnace (valve/filter/furnace) inside a one story ranch home . Since the line begins underground there is no way for it to run downhill.

With the new tank outside it will be higher than below ground, but will still have to be running slightly uphill (down from top of tank but then through level floor joists, then up a bit to the valve/filter. Will this be a problem with losing prime - if so why doesn't the below ground tank now lose the prime? I don't thin it ever has.

yellowdog

i also install a piece of 1/2" hard copper pipe down into the tank from the bottom of the duplex bushing to act as a sleeve to protect the flexible oil line from ever moving from a delivery or anything else. when you run it thru a sleeve, you know exactly where the flex tube is at all times.

EdTheHeaterMan

from your description, the bottom of your replacement tank is at the same level or slightly below the oil burner (No basement).

The reason the fuel lines do not loose the prime? The reason would be the fuel line does not have any leaks. You see a leak can go 2 ways. If the oil pressure inside the fuel line is greater that the air pressure outside the fuel line, because the tank is mainly above the leaking fuel line, the fuel will flow out of the opening. This will show as a drip or slight wetness on or near the leak location. If the oil pressure inside the fuel line is lower than the air pressure around the leak, as in the case of a buried tank, then air will flow into the opening. These leaks are more difficult to locate and fix.

If there are no leaks in the fitting connections or pin holes in the fuel line, then the fuel will not flow out and or air will not flow in the fuel line. A fuel line with no leaks is the goal that every installer of fuel lines is working for. If however you do develop a leak, You want to make it easy to find. Having a fitting at the top of a siphon loop makes it difficult to locate the problem, when you experience nuisance failures resulting from loss of pump prime.

PNJ

@EdTheHeaterMan I'm a little more confused. Yes, the floor of the house is a couple feet above ground, so the bottom of the tank will be slightly lower. With the fuel line bent down from the top of the tank to the floor joists entering the home, the line will then be the same level as the old fuel line.

The current underground tank system I have just has a direct line from the ground, running up to the floor joists and up through the floor to the valve/filter/furnace. There is no Tiger loop or deaerator, not sure if I could even put one of them in.

I'm trying to keep this as simple as possible. Hopefully with a new line there will not be a leak in it, but by your description an outside tank with no loops would make it easier to detect?

So the question is - will installing the new tank above ground and basically following the same fuel line path (no lops/deaerator) going to work the same?

Thanks

PNJ

Thanks @yellowdog great tip, how does the sleeve pipe attach to the bottom of the bushing?

yellowdog

with a 1/2 x 3/8 copper male adapter. the bottom of the duplex bushing is also threaded.

EdTheHeaterMan

I'm sorry, I don't understand your confusion?

PNJ said:

@EdTheHeaterMan I'm a little more confused. Yes, the floor of the house is a couple feet above ground, so the bottom of the tank will be slightly lower. With the fuel line bent down from the top of the tank to the floor joists entering the home, the line will then be the same level as the old fuel line.

and I see no problem or difference with that

The current underground tank system I have just has a direct line from the ground, running up to the floor joists and up through the floor to the valve/filter/furnace.

I see nothing different confusing or problematic there either

There is no Tiger loop or deaerator, not sure if I could even put one of them in.
anyone with half a brain can follow the instructions that accompany the tiger loop, this is an option that you have if you want it.

I'm trying to keep this as simple as possible. Hopefully with a new line there will not be a leak in it, but by your description an outside tank with no loops would make it easier to detect?

Yes, an oil leak is always easier to find that an air leak, especially when the air is leaking IN

So the question is - will installing the new tank above ground and basically following the same fuel line path (no lops/deaerator) going to work the same?
Exactly the same

Thanks

Think of a water tower high in the air. if you put water in the tank high above the homes and buildings that use that water, you get water pressure at the tap in your kitchen, bath, and other outlets. if there is a leak in a pipe in the street between the water tower and your home the water will leak out. Open any fire hydrant on that pipe to see how much water might come from such a leak.

If you have to get water from a river, lake, or well that is below your home, then you need a pump to make the water pressure in your home. If you have a leak in the pipe between the well and the pump in your home, you will find air gets in and your pump may not draw water from the well if the leak is big enough.

Does that picture in your mind's eye make sense?

The oil in a tank below ground needs the pump to lift the oil to the burner. (like the well pump)
The oil in the tank that is above the burner does not need the pump to lift the oil. (Like the water tower) The pump is gravity fed. You still need a pump there is to make the 100PSI (or higher) pressure to atomize the oil thru the nozzle in the combustion chamber.

I hope that makes things a litter more clear... As clear as mud anyway

EdTheHeaterMan

If you are clever, you can make the fuel line from the bottom of the tank, thru the top bushing, thru the compression fitting, thru the house foundation, between the floor joist, up thru the floor near the burner to the first shut off valve... all one uncut piece of copper tubing. I have completed fuel tank installations this way many times.

By uncoiling the 50 ft roll of tubing and inserting it into the fuel tank first. Placing a bend just above the tank to turn the line down to the level of the opening thru the foundation but pointing away from the house. The other end of the uncoiled tubing is then placed across the lawn. The burner end of the tubing is then gradually slid thru the opening in the foundation, between the floor joist, then up to the burner location. Continue to slide the tubing until all the slack outside is used up and the fuel line from the tank to the foundation is where you want it.

I hope this also is clear as mud.

PNJ

Thanks again @EdTheHeaterMan everything's clear except for the bend just above the tank to turn the line down to the level of the opening thru the foundation but pointing away from the house. The tank would be near the house, with the line bending toward it, and between the tank and the wall. How else could I do it?

EdTheHeaterMan

It is difficult to put this into words, although I tried, so here is the diagram of the first step.
1. Remove 48" of plastic cover from the fuel line and install it into the tank thru the top tank bushing as previously instructed above.
2. Uncoil the remainder of the fuel line on the lawn as shown in diagram. Take notice, the bent at the top of the tank is facing away from the house.
3. Take the opposite end of the copper tube (the end that is not inside the tank and place it thru the hole in the foundation of your home where you intend to install the fuel line. (a 1/2" or 3/4" PVC pipe sleeve can make the hole easy to slide the copper tube thru here)
4. Slide the fuel line thru the opening and along the floor joist towards the oil burner, as shown in the next diagram. The bent at the top of the tank is still facing away from the home at this point.
5. Use a helper to insure the fuel line does not kink during this step
6. Continue to slide the fuel line carefully to the hole in the floor where the oil burner is located and draw the excess fuel line form below the floor to the oil burner location.
7. At this point you should be able to dress the fuel line to its final location outside the home between the home and the tank. The bend at the top of the tank is now facing the house as shown in the next illustration.
8. Now you can adjust the fuel line as need outside, fasten the fuel line with vibration resistant hangers to the floor joists and cut off any excess fuel line at the burner location, then install the shut off valve in the burner room.
Clear as mud?

PNJ

Clear as mud. I thought about running the new fuel line under the house first, newer empty tank isn't in place yet. The only dumb question is the one I don't ask, and I just want to do this all right the first time. Can't thank you enough Ed.

One last question, I hope, pouring a concrete slab for the tank. The only thing I read was to keep vent 2 ft. min. from window/openings. Is there any specific minimum spacing requirement for the tank itself, obviously I want it as close to the house as possible but I would still need to have some space (some things say just keep it far enough away so debris won't collect).

STEVEusaPA

EdTheHeaterMan said:

It is difficult to put this into words, although I tried, so here is the diagram of the first step.
1. Remove 48" of plastic cover from the fuel line and install it into the tank thru the top tank bushing as previously instructed above.
2. Uncoil the remainder of the fuel line on the lawn as shown in diagram. Take notice, the bent at the top of the tank is facing away from the house.
3. Take the opposite end of the copper tube (the end that is not inside the tank and place it thru the hole in the foundation of your home where you intend to install the fuel line. (a 1/2" or 3/4" PVC pipe sleeve can make the hole easy to slide the copper tube thru here)
4. Slide the fuel line thru the opening and along the floor joist towards the oil burner, as shown in the next diagram. The bent at the top of the tank is still facing away from the home at this point.
5. Use a helper to insure the fuel line does not kink during this step
6. Continue to slide the fuel line carefully to the hole in the floor where the oil burner is located and draw the excess fuel line form below the floor to the oil burner location.
7. At this point you should be able to dress the fuel line to its final location outside the home between the home and the tank. The bend at the top of the tank is now facing the house as shown in the next illustration.
8. Now you can adjust the fuel line as need outside, fasten the fuel line with vibration resistant hangers to the floor joists and cut off any excess fuel line at the burner location, then install the shut off valve in the burner room.
Clear as mud?

That's a lot of typing and I'm afraid not the best way, or even to code. I agree with sleeving the oil line thru the wall.
For starters, a firomatic valve is required where the oil line enters the house. So all that uncoiling on the lawn isn't necessary. If it were me, I'd still stick with line out the bottom of the oil tank, and right after where the fuel line enters the house, I'd do expansion loops, firomatic, and if feasible, double filtration, then OSV if the oil line entering the house is higher than the burner. Then expansion loops and firomatic at the burner.

STEVEusaPA

PNJ said:

@pecmsg @STEVEusaPA This is what's hanging me up, it appears to be the right way but neither explain exactly why...

I feel my way is better. Doing it their way you'll never get anything that accumulates out of the bottom of the tank without actually cleaning the tank-which is done in Europe, but not here.
Water in the bottom of a steel tank, which always occurs with condensation (unavoidable) will just sit there with a top feed tank, and rot it out and shorten it's life. Bottom feed doesn't allow water to accumulate, and treating the tank annually, or more if necessary, pretty much prevents/eliminates it.

PNJ

@STEVEusaPA it can get down to 0 here in Jan/Feb and I would think eliminating the bottom fitting removes a chance of freeing there. The NORA video I posted here also recommends top fed, although they don't explain why. As for water/sludge/much accumulating at the bottom, can't I drain the tank, or at least drain any water out every year through a bottom plug- since the tank will be pitched down 1/4in. per foot?

Also I have an older furnace, I change the filter 4 times a year and nozzle often (single filter) and don't want muck running through the line.

Firematic valve- my current underground setup I am replacing has the valve right at the floor where the line protrudes/ before connecting to the filter. I am replacing that, so putting it behind the foundation in a crawl space under the house at that tank entry point doesn't make sense, or even seems doable?

This is basically a few year band aid until I can afford to upgrade the entire system and get away from oil altogether.

Thoughts?

STEVEusaPA

You shouldn't have to change the filter 4 times a year, or the nozzle 'often'. Your tank needs to be replaced or abandoned. I don't agree with getting away from oil, but I'm tired of that fight.
And I don't agree with NORA on this. I gave you my reasons.
I've never had a freeze problem with a bottom feed tank, but I have freeze bottoms with top feed.

I'm telling you the best way through my experience, and by code. Do what ya want, it's your place.

How do you plan on draining through the bottom plug? You CAN'T just unscrew it, nor should you have a valve there, because if it does freeze, it probably will crack that fitting/shut off valve.
Straight heating oil won't freeze. Water and bio will. Treat the tank, every fill. or wrap the oil line with heat tape, set it for 40°
Of course the tank is better in the basement. Eliminates all these problems. Cold oil is horrible for combustion too.

PNJ

STEVEusaPA said:

. I don't agree with getting away from oil, but I'm tired of that fight.

I'm tired of paying what 3rd world dictatorships (the13 members of OPEC) and now Russia and the Saudis (OPEC +) are telling me to pay for oil, especially when we have this thing called THE SUN that puts out all the heat you can ever need. The technology has been here we just haven't been smart enough to create an industry around it so it's more affordable for everyone. Not to mention GEOTHERMAL energy.

EdTheHeaterMan

Steve has been known to never have a defective fuel line and that none of the fuel tanks he ever installed have ever had a problem. I also don’t know of a local code official that knows anything about fuel oil tank codes, never mind enforcing them. The firomatic valve just inside the foundation is a great idea when it is accessible. The problem is that Steve won’t be there to go in there and open or close it for you when needed. The method I outlined worked well for me in my 30+ years of working in southern NJ.

Not everyone can make a perfect flared joint in 3/8” copper. It takes practice. Steve has had a lot of practice. So I understand why he would suggest something other than installing a continuous piece of copper with no fittings or connections. The method I outlined will work for you too

STEVEusaPA

I think you need some more sarcasm Ed. I only recommend installing it by code. And code says firomatic where it enters the building, hence, no need to try to do it with one continuous piece. And that's also the best place for the filters, followed up by an OSV to protect the rest of the oil line from disaster, or appropriately placed to prevent more than 3 psi inlet pressure at the fuel pump.
You're going to need flares in many places-around each component along the way up to the burner. Better learn how to do them right, or get someone who can.

Nothing wrong with doing it right. If something goes wrong, does the OP get to tell his insurance company..."But this guy Ed on the internet told me this was ok..."? And the insurance company says "No problem, we got you covered". A local official may not know, but insurance companies, adjusters, lawyers...they all know.

PNJ

@STEVEusaPA I appreciate your help and input, I appreciate everyone's help, but I really don't think it's feasible to move my valve and filter to underneath the house, in a 2 ft. high crawlspace behind cinder blocks & 10 feet from the crawl space opening. It wouldn't be wise, or very clean, to try and change a filter when crawling through dirt on your belly. I'm really just following what's already been there for 50 years, and everything will be newer.

Does anyone know of recommended space between outdoor tank and wall/windows/openings? Some people say 5 feet but that's for PROPERTY LINES, not the wall of the home. All I could find was to keep the vent pipe a minimum of 2 ft. from any house openings, and to have enough clearing for debris not to accumulate between the tank and exterior wall.

PNJ

@EdTheHeaterMan

1. Remove 48" of plastic cover from the fuel line and install it into the tank thru the top tank bushing as previously instructed above.
2. Uncoil the remainder of the fuel line on the lawn as shown in diagram. Take notice, the bent at the top of the tank is facing away from the house.

I am getting this copper line tomorrow https://www.supplyhouse.com/Kamco-31385-Oil-Pro-Tec-Plus-3-8-OD-x-50-Coated-Copper-Type-L-Tubing-Coil-Orange

I don't want to kink it, can I bend this by hand at the top of tank or does it have to be bent downward with a bending tool? How far can I manually bend it before it kinks?

Big Ed_4

Top feed tanks will freeze . My house , cement pad , higher legs , I would use aleast 12" and 13" legs . The difference would' give a good 1/4" pitch to the bottom feed valve . Run the contained oil line directly into the house with a pitch inward . Instal a second valve and general filter as soon as you can . Spin on filter with a vacuum gauge at the burner . The general filter would catch any water .

Top feeds will freeze , well water will freeze , enough in the tank it would freeze the feed line and break the syphon . Ask me how I know that

If it is required to set it up top feed , Then I still would pith the tank , the bottom feed is now a service valve which you have to flush to get the water out. Higher legs work best here , depends on the bucket you want to use ...

PNJ

@Big Ed_4 This seems to be the great debate

https://youtu.be/iFHl0TrkGTc?t=513
(jump to 8:33)

"Outdoor AST's are often connected with the piping installed through the top of the tank to prevent potential water accumulation in the bottom of the tank disrupting the flow of fuel if the water freezes" ~NORA

Bottom tapping to remove water with freeze relief valve under tank, closed, plugged, handle removed.

STEVEusaPA

No debate at all between the people who do this for a living. Have NORA come over and help you. Do what ya want.

PNJ

STEVEusaPA said:

Nothing wrong with doing it right. If something goes wrong, does the OP get to tell his insurance company..."But this guy Ed on the internet told me this was ok..."? And the insurance company says "No problem, we got you covered". A local official may not know, but insurance companies, adjusters, lawyers...they all know.

On one hand you talk about following regulations on the other you say do what's been working for you. So if something goes wrong I'll tell my insurance company..."But this guy Steve on the internet told me not to do what NORA, who trains and certifies oilheat service technicians, recommended. And the insurance company says "No problem, we got you covered" ?

I'm just trying to do the best thing for my situation, isn't this the purpose of the forum? I appreciate everyone's input, greatly.

EdTheHeaterMan

PNJ said:

@EdTheHeaterMan

1. Remove 48" of plastic cover from the fuel line and install it into the tank thru the top tank bushing as previously instructed above.
2. Uncoil the remainder of the fuel line on the lawn as shown in diagram. Take notice, the bent at the top of the tank is facing away from the house.

I am getting this copper line tomorrow https://www.supplyhouse.com/Kamco-31385-Oil-Pro-Tec-Plus-3-8-OD-x-50-Coated-Copper-Type-L-Tubing-Coil-Orange

I don't want to kink it, can I bend this by hand at the top of tank or does it have to be bent downward with a bending tool? How far can I manually bend it before it kinks?

Bending 3/8" copper tubing is not that hard. I learned to make a bend in copper by wrapping it around a coffee can. (approximately 3.5" radius) and seldom had a kink in the line. Any tighter then that, and I would recommend to use a tubing bender. So to answer your question, I would need to ask a question. How tight of a bend do you want at the top of the tank?

STEVEusaPA

PNJ said:

STEVEusaPA said:

Nothing wrong with doing it right. If something goes wrong, does the OP get to tell his insurance company..."But this guy Ed on the internet told me this was ok..."? And the insurance company says "No problem, we got you covered". A local official may not know, but insurance companies, adjusters, lawyers...they all know.

On one hand you talk about following regulations on the other you say do what's been working for you. So if something goes wrong I'll tell my insurance company..."But this guy Steve on the internet told me not to do what NORA, who trains and certifies oilheat service technicians, recommended. And the insurance company says "No problem, we got you covered" ?

I'm just trying to do the best thing for my situation, isn't this the purpose of the forum? I appreciate everyone's input, greatly.

What's code and what NORA states may not be the same thing, or the best thing. And then there's best practices.
I gave you code and best practices. NORA doesn't state how to get the water out of the bottom of the tank, and many experienced people here will tell you water freezing in a valve on the bottom of an oil tank would probably split open and be a disaster. But valve on bottom/line on bottom, oil tank treated with a pour point additive/water eliminator is best. The water won't be in there to freeze, and any moisture accumulation will go thru the valve, thru the oil line and into the filer.
So if you're drawing out the top, don't put a valve on the bottom. Treat with chemicals, hope for the best.

Keep in mind, that's not the first edition of that manual. That has evolved and changed over the years and experienced people's input has always changed conventional thinking in almost every endeavor.
And what's best for you is to get the advice on how a job should be properly done, then get a qualified licensed, insured competent tech out there to do it.

And what's really best if you get a number of days that cold, is not to have the tank outside.

And I'm a NORA Gold-Certified Technician, and have been for many years...(it's not that big of a deal, but it means I put in my time in the field and with my education).