Dissimilar Metals Connection

[30432rc]

It is generally recommended to install dielectric unions/couplings when connecting two dissimilar metals (steel pipe to copper pipe).

I was told that Brass Nipple generally does the same thing as a commercially available dielectric union, is this true?

My application is to tie in a 2" copper pipe into a 6" epoxy coated carbon steel pipe. Any suggestion to avoid corrosion issue?

 

[europipe]

Don´t You have a flange on the steel lined pipe?
A flanged connection is acc. to me better than couplings.
I don´t see how you can get a good connection; liner with couplings.

 

[kenvlach]

Re "Brass Nipple generally does the same thing as a commercially available dielectric union, is this true?"
-- No

 

[PEDARRIN2]

We stopped specifying the dielectric unions because the installers were over torquing the unions to prevent leaks and they were compromising the insulating materials.


We now specify either dielectric couplings with non-conductive polymer liner made by Victualic, Gruvlok or Lochinvar or we specify a flange fitting with insulating materials.