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Repair small section of 3/8 oil line?

Rizz861
Rizz861 Member Posts: 61

If the 3/8" copper going from the tank to the burner has a kink that created a pin hole, can I use a flare coupling to repair it? This person doesn't want to spend the money and just wants it repaired. I've never repaired a section of the fuel line, only replaced the whole thing if it was damaged. Is this an acceptable repair? I don't see why it wouldn't be as the line is sleeved and appears to be in good shape, somebody just happened to drop something on it causing the leak. Thanks in advance for your advice!

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 24,397

    Do you mean physically? If so, yes, if your flares are really really good and you are careful. However, if I were the local building inspector and I saw it, I couldn't get the red tag out of my pocket fast enough…

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Rizz861
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,530

    Hi @Jamie Hall , I know nothing about this. What would the inspector be concerned about? 🤨

    Yours, Larry

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,039
    edited October 2

    I have made that particular repair more than once. if it is leak free once you have made the repair, then I see no problem with it. this is most likely a Post inspection type of repair @Jamie Hall. I have repaired many heating systems that have been inspected after the job was completed years ago, and there has never been any cause for inspection after that initial commissioning of the system.

    Even if it was inspected and you were to attempt to Red Tag that repair, I might ask this: What if the fuel line needed to be more than 50 feet ling, and only 50 foot lengths of tubing were available, What would you recommend to put the two pieces of copper together in order to make the full run from tank to burner? I might think you would recommend a Flare Union. So what makes your union acceptable and my union not acceptable?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    LRCCBJTonyMLong Beach Ed
  • mattmia2
    mattmia2 Member Posts: 10,637

    The michigan mechanical code doesn't seem to prohibit connections in the supply tubing assuming there isn't something weird about the approval of the fittings that prohibits it.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,212

    Yes you can repair it with a flare coupling (no compression fittings) Perfectly fine. No reason to replace the entire line.

    Rizz861
  • mattmia2
    mattmia2 Member Posts: 10,637

    apparently you can also braze it which sounds exciting.

    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,039

    I might do that before commissioning. But if you want to do that after there is oil in the line, you need to flush with water to insure no fumes remain. Then blow air thru to allow the copper to reach brazing temps. Also have a fire extinguisher near by in case there is any residual fuel in the floor where you are brazing. Or you can use a Flare Union.

    Did I mention that I have used a Flare Union in the past?

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • mattmia2
    mattmia2 Member Posts: 10,637

    I don't think it would have flammable vapors at room temp but unless you washed the oil out it would produce flammable vapors when you heated it.

  • HVACNUT
    HVACNUT Member Posts: 6,176

    The oil line looks good on the outside, but what does it look like on the inside? How old is the oil line? How far between the tank and the burner? Will 30 ft of new coated oil line break the bank?

  • ChrisJ
    ChrisJ Member Posts: 16,205

    Flares.

    Good enough for hydraulic brake lines.
    Good enough for refrigerant lines running 400-600 psig.


    They also a different design of flares for high pressure fuel lines on gasoline and diesel engines. Gasoline direct injected engines running 3000 psig and diesel I hear runs as high as 30,000 psig. They're a different angle and design than a normal flare, but still a flare connection.

    I'd call it more than good enough for a heating oil line.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • SuperTech
    SuperTech Member Posts: 2,349

    I brazed a 3/8" coupling on a oil line once when I was an apprentice and just starting to do things on my own. I was more confident in my brazing ability than my flaring ability at the time, lol. It worked but I wouldn't recommend it.

    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,039

    @ChrisJ has a point about higher pressure. There is something called a double flare tool. It uses a additional step to cause a bulge to form at the end of the tubing when you screw down on the tubing. once the bulge is there, then you remove the bulge tool from the tubing and screw the flare tool against the bulged tube. That causes end of the tube to fold in on itself at the flare angel. The outer edge of the flare is always perfect because it does not need to be reamed, because it is not the actual edge of the tube, The edge of the tube is actually the innermost point of the flare. I have used that tool to male custom steel break lines. and the flare fitting was usually Female and the nut was actually the male thread.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • mattmia2
    mattmia2 Member Posts: 10,637

    Brake lines are double flare with reverse nuts. The flange of the flare is double the thickness, the edge is on the inside so a crack can't form from it, and the reverse flare nut exserts a lot more force on the flange than an ordinary flare nut.

    EdTheHeaterMan
  • ChrisJ
    ChrisJ Member Posts: 16,205

    Is a standard flare good enough for heating oil running at near atmospheric pressure?

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • ChrisJ
    ChrisJ Member Posts: 16,205

    I'm surprised no one mentioned brake lines are also steel.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • JUGHNE
    JUGHNE Member Posts: 11,242

    If that flare union was absolutely forbidden…….red tag coming……..

    How about just putting an in line oil filter there? Would you be safe then? Add a valve on either side of it?

    More potential leaks…….but…….Just being a wise guy. 😉

    EdTheHeaterMan
  • Jamie Hall
    Jamie Hall Member Posts: 24,397

    A double flare — brake line flare — I'd be fine with.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    EdTheHeaterMan
  • ChrisJ
    ChrisJ Member Posts: 16,205

    What is the reason you're not fine with a standard flare on a heating oil line?

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    EdTheHeaterMan
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,212

    Standard flares properly done are used on refrigeration where they can't leak and have been used for years.

    The only time I ever had trouble flaring was sometimes old tubing that you were connecting to had become work hardened when flared.

    This could easily be fixed by either heating the tubing to anneal it, Turning the flaring tool back and forth so as to flare it a little at a time and not all at once and using a drop of oil on the flaring tool. Also remover the burr on the inside with a jackknife or reamer before flaring and make the flare as large as possible for more sealing surface. If you make it to big so the nut will not go on just file the outside of the flare a bit.

    ChrisJEdTheHeaterMan
  • JUGHNE
    JUGHNE Member Posts: 11,242

    Out of a couple hundred flares I have made on Minisplits over the years, only one showed up leaking after 2 years of operation with R-410A.

    And this was with the old school flaring tool…..not the approved 410A flare design.

    EdTheHeaterManMiata
  • ChrisJ
    ChrisJ Member Posts: 16,205
    edited October 3

    Curious if Yor-Lok fittings would be acceptable in this application as well?

    I see a lot of people saying compression fittings aren't ok with fuel oil. Why would that be?

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • mattmia2
    mattmia2 Member Posts: 10,637

    The mechanical code enumerates what types of fittings are allowed. Compression fittings are not in that list. I don't know what the technical reason is or if it exists anymore but obviously a flare is a stronger connection than a compression connection and less prone to leakage. Compression fittings tend to have very slow leaks that are hard to detect until months later when you see traces of the fluid they were containing on the outside and tend to unscrew and leak with tortional movement of the tubing. Pressure testing would help some with the initial install but wouldn't help with later movement of the tubing either from expansion and contraction or someone bumping it.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,212

    The normal compression fittings tend to leak when taken apart and put back together. Around here they were in common use for oil lines years ago but are no longer supposed to be used.

    Standard compression fitting I have never seen on refrigeration while flares have been used for years.

    People complain about flares but they just need to learn how to flare correctly.

    LRCCBJChrisJEdTheHeaterMan
  • Rizz861
    Rizz861 Member Posts: 61

    So I went the AHJ route, aka the fire inspector of the town, and he said no go. Run a new line. Thanks for the advice guys, and do agree with the other posts here that the flares should be fine if they're done correctly, but ultimately the fire inspector of the town said run a line so we did. Thanks!

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,039

    The technical reason is that compression fittings are not able to be tightened after the first use. I have experienced compression fittings on an oil filter and on a fuel oil pump. Every year that the filter is changed or the strained cover is removed for maintenance, the compression fitting is stressed a little. The technician may find that stress leads to a small leak. Then the compression nut is tightened. After 3 of those adjustments the compression nut no longer will stop a leak by tightening it against the compression ring. That ring actually cuts into the copper tubing and you can no longer make a liquid-tight or airtight seal.

    The only exception is on the duplex tank bushing. The compression fitting is only there to hold the tubing at the proper level in the tank. It is not there as a liquid or airtight seal. That is because the tubing is not interrupted at that location. The tubing should go straight through the compression fitting to the near the tank bottom.   There is never any reason to tighten that compression nut after it is locked on to the copper.  No need for a leak proof connection there because there is no actual connection.


    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    ChrisJSuperTech
  • mattmia2
    mattmia2 Member Posts: 10,637
    edited October 30

    Can i get flare stops for under sinks and dishwashers so I don't have this problem there?

    Wouldn't have to do the whole angle the tube in thing either.

  • pecmsg
    pecmsg Member Posts: 5,191

    not allowed a flair union but allowed a flair fitting on either end?

    mattmia2
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,039

    Compression fittings under the sink do not get the filters changed on a regular basis. As a matter of fact, I have chrome angle stops under my pedestal sink in my bathroom. I have not needed to touch then for the past 28 years. if you look back at my original statement, compression fittings are a one time fitting. Maybe 2 or 3 times, but not for every time you change the oil filter. (Ask me how I know this after oil burnering for over 40 years)

    I believe my chrome stops might be able to come apart and get retightened one more time before I would need to go the HD and get another chrome supply tube and compression ring.

    Also my tool lit included about 50 3/8" compression rings in 1976, when I first started oil burner service. There were a lot of compression fittings back then. I guess some code official thought that should not be used anymore after a compression fitting failure caused an injury, property damage or death, that required an insurance company to make a payout. That is where most of our code book rules come from, don't you know.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • mattmia2
    mattmia2 Member Posts: 10,637

    Especially with the dishwasher I've had to take them apart a couple times and they always seem to end up with a slow leak that you have to check on for a day or so after you reconnect it. Flare would just be so much faster.

    EdTheHeaterMan
  • Sootmaster
    Sootmaster Member Posts: 30

    Here in Massachusetts as long as it's accessible (sounds like it is). Portion under ground needs to be sleeved so that a leak will ooze out either end and be seen. Flare unions, solder (800 degree? Not sure of temperature), braze - its all good

    Put an OSV on if your having trouble sleeping