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Trap Replacement - Oil Threads?

nz Member Posts: 125
Since I've been replacing my trap caps and discs - I've noticed many of the caps are very difficult to remove. Since I don't plan on moving for a long time - and I presume I'll be replacing the traps again in 5-8 years, I would like to make it easier on myself the next time around.

Is it bad to LIGHTLY oil the threads and then wipe it off, before replacing the caps? I know it will make it back to the boiler if I glob it on, and then i'll have fun skimming - so I want to avoid that.

What is the common best practice for this?


  • gerry gill
    gerry gill Member Posts: 3,078
    shouldn't be necessary.

    they really don't have to go on as tight as they were before usually..just a good snug with a socket set should do it..tho 10 years down the road they may still take a breaker bar to get loose again.
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • icesailor
    icesailor Member Posts: 7,265
    Sealing Threads:

    Someone may contradict this for some reason I am not aware of, but U use Never-Sieze on almost anything that I screw together and I want to get apart in the future.

    That isn't much different than a ground joint plug on a check valve, Before I install one, I take it apart and "fix it up" so that is I ever have a problem, and I need to get it apart, I can.

    But that works for me.
  • Mike Kusiak_2
    Mike Kusiak_2 Member Posts: 604
    Silicone sealant

    Another thing that I find works well on threaded connections is silicone RTV sealant. I have used it on sink trap connections to iron pipe and drain plugs, and 20 years later they still disassemble easily. Also it acts as a sealant so you don't have to torque the threads very tight to avoid leaks.
  • Dave in QCA
    Dave in QCA Member Posts: 1,785
    edited January 2012
    Dunham 1E traps, right?

    I have a bunch of those too.  I discovered that a couple big wrenches, one to hold the trap and another to remove the cap is necessary.  One really stubborn one, I removed the trap from the pipe and took it to the basement where I could put it in a vice.  I have discovered that when they are stubborn, heating the edges of the trap up with a propane torch works wonders.  Sometimes, a little additional persuasion is necessary with a hammer and a cold chisel, aimed in the direction that the cap will thread off.  Not too many taps that damage the cap, but the tapping seems to loosen the cap when it has been in place for 50 or 60 years.  But, don't apply heat to much heat if you think the trap may still be OK as the heat can destroy the thermostatic disc that is mounted from the center of the cap.

    I usually use a tiny bit of laco pipe thread dope, just to add some lubrication so that they come off easy.  That dope does not harden much or dry out and softens with a little heat.  They other thing that I used to use that worked really well to come apart later was a mixture of motor oil and powdered graphite.  Mix it to a paste and then apply.  It is really dirty stuff, to use it sparingly.  I used to use it on boiler feed-water and lwco floats that had to be taken apart annually for inspection.  You want the gasket to seal, but you also don't want to spend an hour cleaning the stuck pieces of gasket off of the mating surfaces, and this worked great!  Nothing stuck at all, so I would think that it would be good for traps too.

    And, like Gerry said, they really don't need to be super tight.  They should seal just fine.

    Did you get rid of your hammers in your garage ceiling yet?
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
  • MikeyB
    MikeyB Member Posts: 696
    Never Sieze

    I agree w/Ice, I use Never Seize on everything in our Engine Room, Traps, gaskets, nuts, bolts etc, etc, we even use the Spray on the Head Gaskets on our Chillers, love the stuff, just hard to clean off your hands, best to wear Surgical Gloves
  • DNW
    DNW Member Posts: 20
    PTFE Tape?

    I may be doing the same thing soon... would PTFE tape help with removal down the road?

  • nz
    nz Member Posts: 125
    Thank you

    Yes - these are primarily Dunham 1E traps. There are a few 2Es. Funny you mention it - I've been able to get the majority of the caps off so far using the method you mentioned - one pipe wrench to counter-torque the trap, and the trap cap wrench - and hitting the cap wrench with a hammer. However, last night one of the caps wouldn't come off, and I ended up taking off the whole body and putting it in a vice in the basement. After a few taps with the hammer, and some more massaging, it came right off. Once I got the cap off - look what I found (see before and after pics). This trap was serving one of the in-wall convectors in my office.

    Thanks everyone for the suggestions, I will try to pick up some of the never seize and/or the RTV silicone sealant. I get the feeling PTFE tape might work but the threads are so thin (only three threads wide) it would probably be easier to use something I can spread on.

    Dave - I did not open up the garage ceiling yet. Haven't had the time to start a larger project like that yet...but I will :)
This discussion has been closed.