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Smith 450 Mills,

EBEBRATT-Ed Member Posts: 15,307
I used to work on these all the time. Yes, you can plug the steam drum and mud drum connections with standard 2" pipe plugs. The drum connections are a running thread with a locknut, washer and gasket. If the sections are bad sawzall or torch the nipples as close to the section as possible and then make another cut about 1' closer to the drum. You can then wrench out the nipples. If they won't come out you can carefully torch them out because a torch wont cut cast iron drums easily.

The nipples are basicly the only thing holding the sections in place. On the back section you have the devided flue with the "pair of pants" you may want some temporary support under the flue pipe.

The sections will burn up with no water in them. I have disconnected intermediate sections and let them cook but not back sections.

I would call Smith in Westfield, Ma. and talk with them. As far as I know this boiler is still made and parts are available.



  • Mike
    Mike Member Posts: 94
    Leak on a Smith 450 Mills.

    I was shown a boiler replacement job. A smith 450 mills, 10 section hot water boiler located in basement of a church. Leaking from the end section. I've found out, that what, I thought was 1 section is actually 2, and the leaking section can be taken out sevice. The sections, are tied together with supply and return barrel, with 2" nips and lock nuts and gaskets. The boiler is full of that white stuff, and will have to be abated ( waiting for results). Can I, try to back out the nipples, and plug or cap the barrel? Keeping the boiler on line, til after abatement is done, and maybe spring. I'm conserned about crushing the nips, and seeing how these are running nips, would a standard tapered plug work? Any of you ever attempt this? Also, taking a end section, out of service? Any thoughts?
  • T-RACY
    T-RACY Member Posts: 10
    450 mills

    are 2 sections leaking or top and bottom nipples leaking? Nipple at boiler section is standard tapered nipple,other end is running nipple that seals to mud drum and top header with special HB Smith seals.
    Repair nipples are aval,consists of a shorter nipple as above and a short male female coupling,a tapered steal ring and a hy-temp rubber seal.
    split ring and seals are also aval.
  • Mike
    Mike Member Posts: 94
    section leaking

    From what i can can tell, the end section, is actually 2 sections. One of those is leaking. Not the nipples. My thought, was to remove the nipples and plug the barrels of the one leaking section. But not sure if barrel can take a tapered fitting? The running end of the nipple goes into the barrel. Also, with that section, now empty of water, am I asking for trouble with heat from the firebox? I'ts a pretty good leak, and looked to be getting larger. I'm trying to buy some more time, but not sure if I can, or if it's worth it. Any thoughts or ideas appreciated.
  • T-RACY
    T-RACY Member Posts: 10
    450 smith mills

    Hi Mike;
    If I recall the sections on that boiler are pork chop shaped joined togather at the header on top of boiler the same way as what You see at the bottom,except hiding under the jacket...or nasty white stuff..
    standard plug with dope will seal header and mud drum.
    leave section open to atmosphere.
    have disconnected the front left section on smith boilers in the past [on a steam boiler]and had no problems.
    I would turn limit down as much as I could on boiler.
    Don't know as I would dare do a rear section lots of aimed that way.
    may be smart to call the Smith rep to be sure.
    Good luck hope Ya get it.
  • Mike
    Mike Member Posts: 94
    Thanks guys.

    I'll call Smith, in the a.m. Thanks for your input.
This discussion has been closed.