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service call

Rich Davis
Rich Davis Member Posts: 8
Just so I know, what is the reason that you can't use a compression fitting on an oil line, instead you should use a flair instead, I know in a lot of cases that compression fittings will hold 29" vacuum and I've used them up to 10,000 psi. Just for my knowledge. Thanks loads


  • steve toland_5
    steve toland_5 Member Posts: 4
    service call

    i recieved a service call from the dispatcher. i was told that there has been numerous call backs for the same problem... burner shuts off on safety. first time there! they had a buried 550 oil tank in the back yard with an exterior boiler entrance. and my luck it was raining that day and impossible to get my body in the boiler room lol :} they had a weil mclain 68 series with a carlin ez1 burner. i was told on my way there that the 3450 burner motot needed to be replaced.. ya right ok, and the call has been coming in since december when they ran emergency new oil lines... i noticed the 2 pipe oil lines went 4 ft out of the boiler room across the foundation and then into the ground. i did not want to make this call painful so i put my vacuum guage on the suction line and ran the burner and had about a 5" vacuum and with the burner off it dropped to 0"... so i knocked on the customers door and asked them if they have a shouvle in the garage. they asked why and i told them there's a problem with the lined and i need to dig them up... so i got the shouvle and dug up to about 3 ft and what did i find a compression fitting on both the suction and return lines, who ever ran those line definitley set the service guy up for failure, but at least i found the problem. i removed both compression unions and installed flare unions. the burner picked up the oil with no problem and held vacuum and "no leaks" lol should i give myself an atta boy or 10 points... lol
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    You get the \"Attaboy\"....

    The guy who installed the compression fittings SHOULD get a "DOPESLAP" !

    I don't care about what the flipping code says...compression fittings are BAD PRACTICE. I can only think of 1 situation where they can be used properly...but then again....what do I know? Good find/catch Steve. Chris

  • This story really explains why not to use compression fittings on oil lines. There was a thread regarding a Riello burner recently and someone mentioned that you can use compression fittings. Anyone can get a copy of NFPA 31, but there is nothing like experience.

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  • Glen
    Glen Member Posts: 855
    In canada

    it is specified in the CSA B 139 Oil installation code where it clearly states "compression fittings shall not be used." It is my thinking that while comp fittings do well under pressure - vacuum is a problem.
  • John@Reliable_14
    John@Reliable_14 Member Posts: 171

    on oil lines they will sometimes loosen over time, due to line movement,which will loosen the nut just enough to let air in,but nothing out. The fuel unit being a vaccum pump only needs (1) teaspoon of air in it to cause problems/ lost of prime.Tightening of the nut has a lot to do with it I think, you can crank a flare nut, but you never crank a compression nut (so you don't crush the bushing or spilt the nut.John
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