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when to use NPT and when to use sweat

heatingFunheatingFun Member Posts: 84
I need 2 sets of circulator isolator flanges. There are two different types: NPT and Sweat.

Usually when we should use NPT and when we should use solder?

Do you think this isolator flange from Taco is good?  It seems different with others.


  • jonny88jonny88 Member Posts: 1,139

    good for you at least you are using isolation flanges.I havent had problems with Taco flanges although I do prefer the Grundfoss model.Use solder if you are piping in copper or some people like to use blk fittings then go npt,good luck.
  • Big EdBig Ed Member Posts: 863

    Say your plan of mounting the circulatorsis off the boiler , for support of pumps better to build manifold in iron , then after you can pipe it in copper ..... say you have two circs in same size , buy a set of each .... if not use adapters ...On a hydronic wall , either or but support pumps with pipe champs ...I wouldn't support circulators in copper alone ...
    I have enough experience to know , that I dont know it all
  • SWEISWEI Member Posts: 7,356
    Isolation flanges

    can be mixed and matched if needed.  It's not uncommon to see black iron on the boiler side and copper tube for distribution.

    Webstone offers an amazing array of options
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