Oil Tank Piping

SuperTech

I did this job as a favor for my brother. He does landscaping and poured the concrete pad and set the tank in place for a good customer of his. He asked me to hook up the oil lines and pipe in the tank. The old tank is a 1000 gallon tank in the ground that my brother will be removing in the spring. 

I connected it as a two pipe system with the pick up tube being 42" long using a 3/8" MPT x 1/2" copper adapter and 1/2" type L pipe.  The return line is 3/8" copper going 36" into the tank. The fill and vent are as pictured. 

The original piping didn't include a filter so I installed a Garber filter with vacuum gauge at the burner.  I replaced the pump strainer and nozzle which were plugged. I replaced the R8184G with a Carlin primary setup for interrupted ignition. I was pleasantly surprised when I combustion tested the boiler and didn't have to make any adjustments. 

I have to go back to finish the maintenance.  Is there anything I should change or do differently? I plan on getting rid of the firomatic valve on the return line. I wanted to replace all the original oil lines but I ran out of copper and the homeowner didn't want to pay for another roll. Any advice would be greatly appreciated. 

STEVEusaPA

Step one...where's the pictures...lol

pecmsg

Why is the return 36" into the tank? Doesn't that put it in the oil after a fill up?

SuperTech

STEVEusaPA said:

Step one...where's the pictures...lol

Dammit. Pictures didn't load because I wasn't home on WiFi. 

HVACNUT

Does it snow there?

SuperTech

I was originally going to insert the return to the same depth as the pickup tube, but I was limited by the amount of copper I had. I figured 3' wouldn't be a problem and I wanted to keep the number of unions and connections to a minimum. I used my Hilmor bender for the 90's, could've came out better I suppose.  I used 1/2" copper two hole straps and exterior screws to secure the lines to the house. 

One thing I didn't get a picture of is the valve at the bottom of the tank.  I used 1/2" brass nipples, a brass 90, ball valve and plug to allow sludge/water drainage during service.  I made sure that the tank is slightly pitched towards the valve.

I'm wondering if I should have installed a check valve on the supply pipe or an OSV. What do you guys think?

SuperTech

Here's the boiler. Poor old WBV-04 from 2006. 

pecmsg

The return tube just goes into the tank. At 3' with a full tank, it can siphon oil during a failure.

EBEBRATT-Ed

I don't agree. The return line should go below the oil level in the tank. If it terminates at the top air can migrate through the return line. It also prevents oil from syphoning back the suction line. If both lines are submerged the oil line system is sealed and there is no need for any check valves but with the burner below the tank i would put one (a check valve) on the return line where it enters the building. Local codes usually require a firomatic where the supply enters the building.

Some locations want some tank protection but that varies.

STEVEusaPA

Here’s some of my thoughts.
Kudos on actually putting it on a continuous solid concrete pad.

1. I would’ve used bottom outlet on tank, single line, insulated and protected in conduit. Having the valve only on the bottom is not good. Water will settle there and if it freezes could split that valve open and dump the contents of the tank.
2. Although might be a bit of a hassle, I’d probably try to follow code and get a firomatic on supply right after it enters the house. Then filter (mounted to wall), then OSV, and another firomatic at the burner. Remove bypass plug, and switch it back to single pipe. If that return firomatic fails or even plugs, (besides being against code) you will instantly blow you pump seal. Also if the return line plugs, freezes or is kinked/dented-blown pump seal.
3. Your supply line runs pretty far outside. Treating tank to prevent freezing is a must.
4. I think your vent is too close to the window. I don’t know code on it but it might
need to be extended a certain height above window.
5. This is definitely an install where I’d use expansion loops-at the tank and at the burner-yeah I agree they are ugly.

Favors are the worse. Seems like they always bite you in the ****. And you probably didn’t change enough, but you’re married to it for life! Lol.

EdTheHeaterMan

I could not help but see a potential problem with the location of the fuel line and how the pitch of the fuel line along with the fact that the fuel line is a soft copper tubing with very minimal high and low spots along the length of the that horizontal run. If you have a condition in the future where some condensation or other water source finds its way into the fuel line, there is a chance that the condensation may freeze in the fuel line causing a blockage, then a no heat situation.

I have mentioned this on other occasions where someone was trying to grasp the concept of how the heat always fails when if gets very cold out. Like when the outdoor temperature drops to the mid teens and colder. Read the 4th paragraph of this post: https://forum.heatinghelp.com/discussion/comment/1607985#Comment_1607985

I would follow @STEVEusaPA advise ...with the addition of 1" per foot pitch of the fuel line, from the tank to the basement. This will let the water in the fuel line find its way to the basement, away from the freezing possibility. He seems to have dealt with this same problem and knows how to resolve the problem before it becomes a problem.

SuperTech

Single pipe from the bottom outlet would have been easier. I was worried about sludge and water settling at the bottom and freezing the line. It seems like every time I see freezing oil lines it's on a single pipe outdoor tank setup.  Maybe with the tank pitched properly towards the valve this can be avoided. 

A firomatic on the supply instead of the flare union isn't difficult to fix. As is adding an OSV and removing the firomatic on the return line. Adding pitch to the lines isn't impossible either.

Thanks for the advice everyone. I should have asked for advice before I did the work. I was hoping I only messed up minor details. I had it in mind that two pipe from the top of the tank was best. I think I read so much debating on it I didn't remember what was the best way.

I'll go back and humbly explain that I was wrong and make corrections. The homeowner would probably prefer it corrected now rather than later.

SuperTech

I ordered the OSV and I have a Firomatic for where the oil line enters the house. Unfortunately due to the length of the outdoor piping it's going to be awfully tough get the required pitch back to the tank but I will do my best to improve it.  
 
I was reading on Inspectapedia about how they recommended installing a oil tank shows them only using a 6" nipple as the return line into the tank. Wouldn't this cause the same problem as my 36" return line? Or does the check valve they installed near the burner eliminate need for a return line to the bottom of the tank? They also have the OSV at the burner, not where the lines enter the house. 

I'm sure the way Steve said to do it is the best way, I just want to know if what they show is correct or not. 

It looks this job will be a good learning experience even if I don't make much money from it.  It's ok, I value knowledge more than anything. 

MaxMercy

I would have done a single bottom draw oil line with a properly pitched tank.

pecmsg

EBEBRATT-Ed said:

I don't agree. The return line should go below the oil level in the tank. If it terminates at the top air can migrate through the return line. It also prevents oil from syphoning back the suction line. If both lines are submerged the oil line system is sealed and there is no need for any check valves but with the burner below the tank i would put one (a check valve) on the return line where it enters the building. Local codes usually require a firomatic where the supply enters the building. Some locations want some tank protection but that varies.

But doesn’t that now require a firematic on the return?

EBEBRATT-Ed

@pecmsg

I have never seen a check valve or a firomatic on a return required by code. But I am usually wrong.


This is the way I think of it.

If you had a hospital with an underground tank and the boiler room was two floors below ground level and you had an oil transfer pump feeding multiple boilers and the transfer pump is hooked up two pipe. Let's say it's #6 oil and you Have to put the return line to the bottom because #6 is always heated . And the pumps and the boiler room are well below the tank you could get a syphon from either line........... if they broke.

Does the code require a firomatic on the return line? Do they prohibit check valves in the return line or anywhere else for that matter?

I don't think so.

There are all kind of "what ifs" and the inspector said this or that or somebody told me this or that. But "what if" are usually not in the code.

Different jurisdictions have different rules but I have never seen it in writing. Especially in a code.

SuperTech

Unfortunately in my area nothing gets inspected and no one follows the code. I'm grateful to have learned that single pipe from the bottom of the tank is the best way to pipe an oil tank in this situation. I usually see outdoor tanks installed in a two pipe configuration. I was under the impression that pumping the dull capacity of the oil pump would prevent freezing oil lines.  Now I know that two pipe is only best when the burner is below the tank.


I know firomatic valves should not be on the return.  I was already planning on removing the one that is there. But what is the best place for a check valve on a two pipe setup? I never see check valves or OSVs used in my area..

Robert O'Brien

STEVEusaPA said:

Here’s some of my thoughts.
Kudos on actually putting it on a continuous solid concrete pad.

1. I would’ve used bottom outlet on tank, single line, insulated and protected in conduit. Having the valve only on the bottom is not good. Water will settle there and if it freezes could split that valve open and dump the contents of the tank.
2. Although might be a bit of a hassle, I’d probably try to follow code and get a firomatic on supply right after it enters the house. Then filter (mounted to wall), then OSV, and another firomatic at the burner. Remove bypass plug, and switch it back to single pipe. If that return firomatic fails or even plugs, (besides being against code) you will instantly blow you pump seal. Also if the return line plugs, freezes or is kinked/dented-blown pump seal.
3. Your supply line runs pretty far outside. Treating tank to prevent freezing is a must.
4. I think your vent is too close to the window. I don’t know code on it but it might
need to be extended a certain height above window.
5. This is definitely an install where I’d use expansion loops-at the tank and at the burner-yeah I agree they are ugly.

Favors are the worse. Seems like they always bite you in the ****. And you probably didn’t change enough, but you’re married to it for life! Lol.

As usual, I agree with Steve. Outside tanks using a top feed need secondary containment per NFPA31 7.8.7 see attached

SuperTech

Yes, I read about that last night.  I've never seen that before. Unless you count the Roth tanks as having built in secondary containment. 

I can always count on @STEVEusaPA to know what the best practice is.  And I have learned a lot from him over the years but obviously not enough 

leonz

The Highland tank Petrohopper which is a tank within a complete tank as an option.

STEVEusaPA

@Robert O'Brien When was 7.8.7 added?

Robert O'Brien

STEVEusaPA said:

@Robert O'Brien When was 7.8.7 added?

2020

EBEBRATT-Ed

So the way I read 7.8.7 is if you come off the bottom you don't need secondary containment. If you come off the top or side you do??

Am I reading this right?

It makes no sense to me that secondary containment is not needed coming off the bottom but is on the side or the top.

Tell me if I am not reading it right.

And why the requirement for secondary containment outside but not in a basement?

I understand no one here wrote the code. Just looking for the reason.

Robert O'Brien

EBEBRATT-Ed said:

So the way I read 7.8.7 is if you come off the bottom you don't need secondary containment. If you come off the top or side you do?? Am I reading this right? It makes no sense to me that secondary containment is not needed coming off the bottom but is on the side or the top. Tell me if I am not reading it right. And why the requirement for secondary containment outside but not in a basement? I understand no one here wrote the code. Just looking for the reason.

Water will be trapped in tank in top draw or side tap configurations. It can drain out in bottom draw assuming the tank is pitched per code. Outside tanks collect more water than inside, hence the code change. BTW, I am on NFPA31 committee currently but was not in 2020 when this was written 

EBEBRATT-Ed

@Robert O'Brien

Understood. Is the increased water due to an increase in condensation due to the tank being outdoors?