I could use a little help with clogged fuel oil #2 line

clydesdale

I have two 275 gallon tanks. Oil supply company determined one of my tanks must be clogged. My gauge showed I hand less than a 1/4 tank left and I should have required 375 gallons ish to fill and it only took a little about 200. So..... they feel one tank is clogged. My burner guy said I can unclog the line using my air compressor and 30# of air pressure. Can someone expand on this for me? Do I :
1. shut off boiler
2. use 3/8 wrench to shut off pump - a grease fitting looking fitting at 5 O'clock on the pump - I need more clarification on this. Am I bleeding off fluid from here to prime it when I re-connect? He gave me these directions 3 months ago and I had bigger fish to fry since I burn wood for heat.
3. disconnect lines at boiler.
4. Shut off the valve at the bottom of the tank with the gauge and keep the valve open for the other tank, which we think is plugged.
5. blow air back into line and tank

If I do blow back into tank, do I need to make up fittings or just use a blow gun with a rubber end that will fit in/over supply line opening.

Boiler guys says I can do this, but don't do it at night in case I need his help.

I just banged on both tanks and the both sound like the have empty volume in them. So, part of me wants to get another oil delivery since tank is showing about 2/3 full and have my IR camera ready and watch the fuel enter the tank and see if it just goes right to just one of the tanks or evenly distributes.

Thoughts?

Thanks.

LRCCBJ

Before any conclusions can be made, we need to know the piping setup. Either photograph the lines coming into the two tanks or explicitly detail the supply piping and the piping for the whistle.

If it isn't piped properly, it is very possible for the oil company to stop the fuel well before the second tank is filled. If the tanks are bottom feed, they will equalize in under 24 hours.

clydesdale

The first image is the tank without the gauge and the one that is in question. This tank is filled first and then spills into the second tank. I have lived here for 7 years and have never had an issue with 3 different companies filling the tank. Thanks.

HVACNUT

Your burner guy isn't an oil burner guy. They make hand pumps for that exact purpose. 

Mad Dog_2

This is NOT a DIY or Homeowners Saturday project.  Mad Dog 🐕 

leonz

Shades of the Southern Pacific tank trains!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Is the safety whistle pipe the second horizontal pipe????

I am really surprised to see this.

With system set up as is it cannot be used as a top draw
unit unless you install a top draw pipe in each tank and tee
them together to feed the burner with one line.

EBEBRATT-Ed

Using copper for the fill and vent is ok but it cannot be soldered it can only be brazed or a mechanical fitting. Sounds like a plumber with no oil experience.

If you don't know how to clear the line you should get some help you could damage the oil pump or cause other problems.

Shut valves at the tank. Disconnect burner line at burner. hook compressor up at oil line at burner and blow back through each tank separately. Open the valves at the tank before pressurizing. Do one tank at a time. I would then put in a new oil filter and bleed the line.

Do this at your own risk. I recommend an oil tech

LRCCBJ

clydesdale said:

I have two 275 gallon tanks. Oil supply company determined one of my tanks must be clogged. My gauge showed I hand less than a 1/4 tank left and I should have required 375 gallons ish to fill and it only took a little about 200.

Thoughts?

Thanks.

The only way this is possible is if the first tank is totally full of oil and the entire delivery crossed to the second tank and filled it.........as verified on the gauge in the second tank.

However, you have confirmed that BOTH tanks have air volume AND the second tank does not register full as verified on the gauge.

So, I don't believe you can trust the conclusion of the oil company at this point.

leonz

I neglected to add this late last night:

I am speaking as a homeowner that burned heavy and light oils since 1978 in a buried tank-

You appear to have a long stress crack on the horizontal copper pipe leading to the second tank and a stress crack on the down pipe as well. You may very well have a long stress crack or cracks on the other pipes as well.

If you keep this system you need to at least install a second fuel gauge to the second tank as well.

When oil is pumped into these single wall tanks in this manner the delivery pump places a great deal of stress on the piping and the tank walls of the first tank and the weight of the oil continues to place stress on the piping and the first tank until the pumping stops as the weight of the oil and pressure surge of the oil in the first tank eventually equalizes with the second tank.

These tanks and the copper pipe have been placed under radial stress from both pumping and the radial stresses against the primary tank and it welds since they were installed and filled every month during the heating seasons in the 7 plus years since they were installed with copper piping.

Normally each oil tank would have its own filler pipe and safety whistle pipe and use black iron pipe for both pipes.

It may be time to seriously think about removing these tanks and replacing them with a single larger exterior tank like a 550 gallon or larger true double wall Highland Petrohopper and using a remote gauge mounted on the tank or indoors.

You would be able to easily use a 2 pipe oil system for your oil burner with a petrohopper.

I speak from my personal experience and having been victimized where I was told by an "oil burner service tech" that my buried tank was full of water in 1978 and well it was not, and there was a mess that was cleaned up when it was removed. The tank was not full of water.

The Highland Petrohopper is a true pressure tested steel tank within a tank oil storage system that uses top draw tappings to deliver fuel or oil and has a long tank vent pipe supplied by Highland that can be shortened if desired to allow the use of a safety whistle.

My buried tank used a Petrometer and they are a very reliable method of monitoring a fuel systems volume.

Big Ed_4

A push-pull pump is the safest way to clear the equalizing line . It's not a high pressure system . Ask me how I know that ...

LRCCBJ

leonz said:

I neglected to add this late last night:

I am speaking as a homeowner that burned heavy and light oils since 1978 in a buried tank-

You appear to have a long stress crack on the horizontal copper pipe leading to the second tank and a stress crack on the down pipe as well. You may very well have a long stress crack or cracks on the other pipes as well.



When oil is pumped into these single wall tanks in this manner the delivery pump places a great deal of stress on the piping and the tank walls of the first tank and the weight of the oil continues to place stress on the piping and the first tank until the pumping stops as the weight of the oil and pressure surge of the oil in the first tank eventually equalizes with the second tank.

These tanks and the copper pipe have been placed under radial stress from both pumping and the radial stresses against the primary tank and it welds since they were installed and filled every month during the heating seasons in the 7 plus years since they were installed with copper piping.

A 2" pipe will see 3 psi at a flow rate of 60 gpm over a length of 6 feet.

It's pretty difficult to make the conclusion that a stress crack will ever develop in 2" drawn Type L copper with a working pressure rating of 607 psi.

The radial stress in the first tank will also be a bit less than 3 psi (due to the short length between tanks) during the transfer to the second tank which is certainly within the manufacturer's specifications for these tanks.

If you still have a concern, ask the company to deliver at "slow flow" at a point where the first tank is filled.

EdTheHeaterMan

I have read the specifications of how to install 2 or more fuel tanks in a basement. There are several correct ways to do it, and one of them is to use one fill pipe and a cross over pipe to the second tank with a bent in the second tank. It is a perfectly legal, and appropriate way to do this. I however, don't particularly care for it. As a former fuel oil delivery truck driver, I feel that this method puts too much pressure on the installer to get it right. Because they never do.

From the photos posted you can clearly see that the pipe thread sealant on the cross over pipe has failed. This may be a case of the weight of the empty tank to the weight of the full tank changing every time there is a delivery causes a small amount of settling to take place and shifting the hard piped crossover to make small movements over the years, or it may have just been a poor connection from the beginning, The bottom line is that there is oil seepage at that location . It is clearly visible on the top of the tank.

The family business I grew up in, had a policy of installing a separate fill and a separate vent pipe with a vent alarm for each tank. It only takes about 38 seconds to swap the fill nozzle from one fill pipe to the other fill pipe and start filling the second tank. Then there is no hydrostatic pressure (or hydraulic pressure. Not sure which term is correct because I’m not an engineer) inside the full tank as the fuel travels thru the cross over pipe.

I have even noticed that the vent pipe and the fill pipe on single tank installations in basements have that oil stain at the top of the tank, around the vent pipe connection that exists the basement. I even remember installing tanks myself and was sure that the vent pipe was properly sealed with RectorSeal #5 and tightened with a 24” pipe wrench and they still had an oil stain on the pipe connection. I believe that oil tank tappings are just factory designed to leak no matter how good you are at water or steam piping. It’s only 2” but the threads are only about ½” deep. Just a poor design.

So why put yourself in that position. Two separate fill pipes, two separate vent pipes and no cross over pipe. The cross over happens at the bottom where the ½” bottom tappings each have a tank valve and tee together to go to the burner location. That way if there is ever a problem with one tank you can just shut it off, you can use the other tank without depending on the second tank for filling or venting or anything else.

Just an old oil burner man’s rant on inexperienced or ignorant tank installers that don't have to deal with their mistakes because all they do is read the engineers drawings, neither of which ever need to go back and actually work on this stuff.

Robert O'Brien

EBEBRATT-Ed said:

Using copper for the fill and vent is ok but it cannot be soldered it can only be brazed or a mechanical fitting. Sounds like a plumber with no oil experience.

If you don't know how to clear the line you should get some help you could damage the oil pump or cause other problems.

Shut valves at the tank. Disconnect burner line at burner. hook compressor up at oil line at burner and blow back through each tank separately. Open the valves at the tank before pressurizing. Do one tank at a time. I would then put in a new oil filter and bleed the line.

Do this at your own risk. I recommend an oil tech

NFPA 31 specifically disallows copper for Fill/vent piping

EdTheHeaterMan

Robert O'Brien said:

@EBEBRATT-Ed said using copper is ok but....

NFPA 31 specifically disallows copper for Fill/vent piping

I have not seen that particular section in reference to residential tanks, But do remember something about mechanical fittings or braised joints in the NFPA31 code book from many years ago. Has there been a recent change I'm not familiar with? (recent = last 12 years)

EBEBRATT-Ed

@EdTheHeaterMan

I seem to remember copper could be used and I specifically remember no solder but brazing is (or was) ok. Maybe it changed.

I dislike the one fill cross over system and never installed one. 1 fill/tank and a common vent is ok if the vents are pitched correctly.

Up until about 10 years ago MA always required a 2" fill & 1 1/4 vent. Never had any issues with that. Why they went to same size fill and vent I guess they figured if there the same size you can't fill faster than you can vent but to me the smaller fill creates more foam.

Big Ed_4

The only problem with a 2" vent is the weaker whistle...

BDR529

Can you say "swing joint" Billy?