Joining pipes of different metals?

Question

I have heard that when you join pipes made of diffrerent metals, such as a copper pipe and an iron pipe, you have to use a dialectric between them, to avoid corrosion at the joint.

What if you want to put an NPT connector on the end of a copper pipe? If the NPT connector is made of something other than copper, do you need a dialectric between it and the copper pipe?

Answer 1

unbelievable answer rick.  YOU SHOULD BE SHOT!  no wonder you are still "Unlicensed".

dissimilar metals such as you have described should be joined with either a dielectric union or "BRASS".

check with the legal codes of your city.  in the past i have used dielectric unions to pass inspection, but the truth of the matter is you cannot beat brass.  i have seen dielectric unions eventually close off due to corrosion.

so whether you choose a brass nipple in between or a brass union or coupling, as long as you have "brass" in between, you'll be legal and in good shape.

Answer 2

working with a plumber for more than 30 yrs ... I have hooked many pipes together....

You basically just use a female and male adapter of what ever type of pipe you are using.... so you end end your copper with a female adapter then you just use a male adapter of what ever the next pipe is, and go on with that .. be it plastic or iron pipe!! I just use a bit of pipe dope at the joint to form a good seal!!