galvanic/ dielectric factors?

[pybyr]

for background, I have an Econoburn boiler with 2" steel inlets and outlets

my primary loop (for a primary/ secondary system) is 1.25 thickwall copper

not precisely sure yet how I will hook the boiler to the P/S or the primary to the copper water to air HX

but-

I sure don't want to get any of this wrong and have it fail in my lifetime, which is hopefully at least 3-4 decades out--

so--

remind me, please , gang, of anything that I need or should be careful of regarding connections between dissimilar metals

can I put copper fittings into/ with steel or iron, or brass with/ in-between/ any of the above/ or do I need to put some dielectric unions in between?

thanks

 

[DaveBP]

Trevor, I think putting brass or bronze between copper and iron is generally regarded as safer. One of the pros will chime in here with more authority, but for the price of a few brass adapters I'd try to stay away from what Tarzan would consider bad joujou.

 

[BrownianHeatingTech]

In a closed system, dielectric action will be minimal (so long as you don't introduce things like zinc by using galvanized pipe).

If you're worried, a decent water treatment would be better than worrying about metals. Lots of steel and iron boilers are installed with copper adapters threaded directly into the boiler block, without incident. Failures only occur when there's a leak that causes introduction of fresh water.

Joe