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Changing old vents--what will go horribly wrong?

I'm getting ready to replace the 3 main vents on my early-1900s steam system.  This is new territory for me, and a couple of the vents look pretty old, so I want to be prepared for the worst.  Do these things ever break when you try to remove them?  What do you do if they're stuck so tight you can't get them off with a pipe wrench?  What else can go wrong?

The vents that are currently on there are one Dole 6B and two that appear to say "Richardson Bellows".

Many thanks to everyone on this forum.  I've learned a huge amount by browsing the archives and reading Dan's books. This is our first winter in our new steam-heated house, and it's become apparent that the system hasn't been well taken care of and needs a lot of work.


  • ALIGAALIGA Member Posts: 194
    few things to try

    - heat it up with a propane torch

    - try the candle wax trick

    - wd40

    - worst case if it breaks, make small cuts and chisel it out.
  • JeffMJeffM Member Posts: 159
    not WD40

    A better option than WD40 if you're looking for a penetrating oil to loosen stuck threads is Kroil, or PB Blaster if you can't find Kroil.
  • Vent removal

    An open ended wrench on the flats of the vent exerts more force than a pipe wrench, especially when tapped with a hammer.--nbc
  • CapeCodderCapeCodder Member Posts: 14

    Thanks everyone.  I'll probably start banging away this weekend.  I'm sure there'll be more questions to come....
  • conversiontimeconversiontime Member Posts: 87
    cheater bar

    I would use a cheater bar/piece of pipe slipped over the wrench vs banging with hammer which is often ineffective and dangerous when you miss or it bounces. When removing 90 year old mains that were completely crusted/rusted in, I was only able to get them out using a 4 foot piece of pipe (old fly fishing metal/rod) tube fitted on top of a large adjustable wrench. Physics in action.........
  • CapeCodderCapeCodder Member Posts: 14
    Good idea

    I'll give that a try.  I have a feeling those Richardson vents have been on there a long time.  The threads are rusted, and the pipe around them looks pretty gnarly.  That's why I'm a bit nervous about trying to remove them.
  • RodRod Posts: 2,067
    Changing Main Vents

    Hi - When first read this I thought about using a cheater bar too!  1 1/4 pipe will slip over the handle of most smaller sized pipe wrenches. (take the wrench with you to verify this) Get one 36 inch long ( or shorter if clearance is tight) cut for you at Home Depot.

    It can be rather hard on the wrench but will get the fitting off.  If you use Teflon tape when you replace the vent, start the tape a couple of threads back from the end to prevent small pieces of the tape from falling into the pipe and possibly clogging the vent orifices.

    - Rod
  • MDNLansingMDNLansing Member Posts: 297
    Steel or Not?

    Are the vents steel (iron) or something lighter like copper?

    Also, are they tapped into the mains themselves, or into a fitting like an elbow?
  • CapeCodderCapeCodder Member Posts: 14
    on a T

    Each vent is mounted on a T at the end of the dry return where it drops down to the Hartford loop.  There's no nipple or anything.  They're just screwed into a 3/4 inch (I think) fitting.  The vents aren't copper.  I'd guess they're steel.
  • MDNLansingMDNLansing Member Posts: 297
    Slow and Careful

    Just take your time. You obviously don't want to break the fitting. If you do use a breaker bar be gentle and take your time. If it won't come out you'd be better off cutting it and removing the threads than breaking the T, especially if your mains don't have unions nearby. The fitting is going to be weaker than the valve so just be mindful not to crack it.

    If you do have to cut them off, or the vents break off leaving the threads in, you can cut them out. Make a few cuts inside the threaded portion and chisel out the small pieces. Once they are out you can chisel out the remaining pieces. If you aren't comfortable doing that yourself, have a plumber cut them off. You don't want to cut them off and have to wait 5 days for a plumber. You're boiler will run but it won;t build pressure so it will just cycle until the thermo turns it off. Not a good situation when it's cold outside.
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