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Cast Iron or Malleable Iron Fittings?

I've seen lots more defective cast fiittings than BM. The cast are cheaper if you can find them but they can and will crack if you over-tighten them.

If you want to break it apart in the future use a couple of BM unions. Thats what they are for.

I recently got into the habit of using unions on all of my boilers. It just makes sense to me. Some day you might be called out to change out that boiler.


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Comments

  • Bill D.
    Bill D. Member Posts: 1
    Cast Iron or Malleable Iron Fittings?

    I'm replacing an old 1934 Steam boiler with a 2003 Steam boiler. In the process of balancing out words of wisdom, hype and experience I've have run into a lot of contradicting opinions. My latest dilemma is whether it matters that I use malleable iron or cast fittings on my near boiler piping. Any thoughts?
  • Sure

    Cast is usually used, because you can break the fittings with a hammer.


    This means that if you need to take it apart in the future, you can break out a fitting and save the pipe threads on the pipes for reuse.

    Both types work, other than that. Cast is sometimes less money, and usually less availlable. Maleable is stronger.

    Noel
  • Geo_2
    Geo_2 Member Posts: 76


    Right Gary, and some good quality ball valves, don't you just love walking into a boiler room w/4 or 5 stories of water above it and not a shut-off in sight.
  • Mad Dog
    Mad Dog Member Posts: 2,595
    Go with Cast Iron...they are ..............

    chunkier and therefore more durable over time, they can be removed easier, and what's wrong with using some finesse when doing screw pipe and NOT overtightening? Do we use malleable when we are stuck? sure! But, we do not choose to use them. Besides. they give a much more impressive look when done. Everyone wants to make tasks idiot-proof. Keep craftsmanship alive.....go Cast Iron. Mad Dog

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  • Mad Dog
    Mad Dog Member Posts: 2,595
    we usually use \"onions\" on All our boilers......................

    but alot of guys out there don't do it - even on water heaters, because they feel that ho's and handymen are more likely to attempt the replacements themselves - and they are right...but I still like to do it. When I went thru apprentioce training with Local #2 in NYC, they taught us that "unions" were the way to go....maybe it was subliminal.......Mad Dog

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  • My 2 cents

    I use malleable as much as possible . The main reason is that it is pretty hard to find everything you need in cast iron , especially when you go over 2 inch diameter . And mixing cast and malleable looks horrible on a steam boiler .

    If you use some Teflon tape on the pipe with a good soft setting sealant , unscrewing a fitting - cast or malleable -is much easier , and you would not need to crack a cast fitting to get the header apart .

    You can grip a malleable fitting in a pipe wrench much easier than a cast fitting .

    And personally , I like the look of malleable over cast .
  • Visible Unions Encourage DIY

    You deserve some kind of award for ambiguity in that one Mad Dog.

    Here I thought it was just to save a buck initially and make an extra few when it's more time-consuming to replace later...
  • pfitter_16
    pfitter_16 Member Posts: 2
    cast iron

    There comes a time in every mans life when he stands at a cross roads and must chose which path to take. There is not always an easy or clear answer. Sometime shades of gray cover the choises in a fog. In heating as in plumbing and as in every other endevor that a man might persue, there may be as many "right" ways to to things as "wrong" ways. You must chose what is "right" for you, and even harder, decide why it is "right"

    When piping steam or hot water heating, and using screwed fittings, I choose Cast Iron. Why? For me, its the right thing to do. This is how I was tought. For all the reasons in the above posts. Thats how it shows in the manuals I have read. It looks better (to me). Its how my father did it. Its how My union tought me. Its how its been done for years.

    With out a doubt I could go on.

    In a pinch I will use BM in place of cast Iron. I know that many here can and will pick apart all the above reasons, and rightfully so. So why do I continue to use Cast Iron over BM? Because when I go home at night and lay awake in the darkness I will know I did the right thing....

    p
  • Cast Iron

    I like the cast iron, myself. I really don't care that these systems that outlast several boilers only run for 75 to 150 years. That's how much life your other appliances are expected to have, isn't it?

    Or your tools and transportation?

    How ancient is your computer?

    I'll take the cast iron. It's beginning to look like it will hold up.

    Noel
  • TGO_35
    TGO_35 Member Posts: 1
    Looking for Elvis

    Has anyone ever seen a a fitting - cast or malleable on a low pressure system wear out? I don't mean corrosion from a leak but wear out from the friction of the steam. The only points in favor of cast fittings seem to be lower cost and ease of replacemant. Malleable are used on process steam (required) and they seem to be the one thing that doesn't leak. Is it possible that cast fittings were the first ones avalible when the dead men got started, and now we are all cutting the end off the pot roast even though we have larger pots? If anyone knows the history of what fittings became avalible when I'd sure like to know.
  • Mad Dog
    Mad Dog Member Posts: 2,595
  • Mad Dog
    Mad Dog Member Posts: 2,595
    On Long Island, across the board.....Cast Iron is more expensive

    than malleable. For some sizes, it may only be 75 cents more, but the bigger sizes are dollars apart. Whether it's ball valves or fittings We NEVER go with something because it's cheaper. Quality comes first. There's nothing wrong with using malleable, it works, and sometimes we have to use 'em. But as the other fella posted. It was the way I was taught too, and , man! I just like the chunky look - formidible. Mad Dog

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  • Mad Dog
    Mad Dog Member Posts: 2,595
    you are right on both counts...........................

    definitely harder to get cast fittings and it IS a personal preference. I prefer the look of Cast. they both get the job done Mad Dog

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  • JohnNY
    JohnNY Member Posts: 3,226
    I agree with Mad Dog

    It doesn't matter that bm fittings are stronger. The tolerances of both materials FAR exceed their usage here. Cast iron fittings are for use with steam. Black malleable fittings are for gas pipe.
    If for no other reason, gas and steam pipes should be easily identifiable throughout a structure.
    When I see a steam boiler piped in bm fittings I'm inclined to think that a shortcut was taken. It's easier and takes up less space to stock one type of fitting rather than two.

    Finally, is there nothing to be said for just plain tradition? What really is at stake here?

    It's consistent with the antiquity of the system.

    Here, on the Wall, we talk about the Dead Men, old piping practices and designs, ancient books about steam and distinguishing ourselves from the hobbyists all with such reverence.

    It seems so simple to me, guys; Use steam fittings on your next steam boiler.

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  • TGO_37
    TGO_37 Member Posts: 1
    JohnNY and Mad dog

    For the record, I use cast fittings on all my steam jobs, as well as black pipe and the highest quality parts I can find - regardless of cost. It is getting harder and harder to find cast fittings above 2", even from NYC supply houses. I did a 1500 sqft boiler this summer and had to buy from 4 supply houses to get everything I needed. I'm still waiting to hear if anyone has seen a worn out steam fitting, cast or malleable. Tradition is a good thing, but we should realize that is the reason we are using cast - not because it's a superior product.
  • Mad Dog
    Mad Dog Member Posts: 2,595
    I've seen your work Tom, you do not have to explain ANYTHING

    You are a top-notch mechanic. I agree that they are harder and harder to get, but if u bust your suppliers chops enough - they will bring them in. I used a supplier a few years ago that told me that Ward was not making certain fittings anymore - found out he just couldn.t be bothered...never gave him another dime. If you need the odd stuff...in the future, call WEBSTER Plumbing Suppklyu in the Bronx...they got it all. Also, my supplier, George CHRIST and SON in NEW Hyde Park caters to all my cast Iron whims. They will get what you need 516 328-0499 ask for Joe or Chris. It is a preference thing, but JOHN NY did make some great points: Tradition and clearly distinguishable systems(even though we see some old gas installations with cast fittings). Keep piping!!!!! Mad Dog

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  • Mad Dog
    Mad Dog Member Posts: 2,595
    Brilliant response John!!!!

    TGO is right too, it is not that malleable will not hold up, but a passing down of tradition. With the constant onslaught of bad craftsmanship, and quick fix products and methods, I will carry the mantle of tradition until I no longer can, and hopefully will pass it on to another young pup. Tradition means something....if it didn't stand the test of time, it would not be honored today. Mad Dog

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  • JohnNY
    JohnNY Member Posts: 3,226
    Supply houses in NYC

    As long as there is Davis & Warshow, we New Yorkers can get just about any plumbing fitting we want with a phone call.

    Last month, I was short-handed (go figure!), and had to install a steam boiler. I went and measured every center-to-center piece and fitting I would need for the near-boiler piping and faxed it to D&W. The next day the whole order arrived, with the boiler, and I stayed there and assembled it. I didn't cut a piece, I didn't take a nipple off my truck. I had nothing left over.

    The order included all 1.5", 2.5" and 3" cast-iron fittings
    and eccentric couplings.

    If you're not using them, you probably should be.

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  • TGO_38
    TGO_38 Member Posts: 2
    Hi John

    D&W was one of the 4 I used. I deal with the Farmingale branch and they in turn call the order into the "city". I don't recall which fittings they didn't have but there were some. Which branch do you use and more importantly who do you talk too? Many years ago I called in a center to center measurment for a 3" nipple and was told that I had to supply the nipple lenght, they couldn't figure the lenght. I know if I spoke to the right person I could get what I need - just haven't found them yet.
    Thanks
  • TGO_38
    TGO_38 Member Posts: 2
    Thanks Matt,

    for the supply houses - I will keep them in mind. Hope you and your Mom are doing OK - how about an update once in awhile? I'm sure alot of us here want to know how she is.
    Regards
    Tom
  • JohnNY
    JohnNY Member Posts: 3,226
    The right guy is...

    Peter Roland. He is in the headquarters in Maspeth (718.937.9500, http://www.daviswarshow.com) He is also an owner/partner.
    I rarely ever deal with their branches because of the problems you're describing. I call him for just about everything and have it sent to a Manhattan location or to my shop. Their fabrication shop is excellent. Tell him Johnny from Gateway Plumbing said "Hello!"

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  • TGO_41
    TGO_41 Member Posts: 1
    Thanks John

    I'll talk to him next time I deal with D&W.
  • Mad Dog
    Mad Dog Member Posts: 2,595
    Thanks Tom, I didn't want to overdo it......since this is a

    heating site. Today we take Mom in to NYC to get going on a cutting edge clinical trial with 3 promising drugs. She has a very aggressive and tenacious form of cancer , Metastatic Melanoma, which doesn't respond well to traditional radiation and chemo. So, this is her best shot. Thanks for the concern, I will keep you boys posted. Matt

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This discussion has been closed.