Steel tank fitting to copper pipe to pex?

[kuribo]

Do I need to worry about dissimilar metals issues if I wish to plumb the steel fittings on my propane storage tanks to copper pipe, which will connect to my pex? Anyone use brass between the steel tank fittings and the copper pipe?

 

[maple1]

Hope not - I've got steel meeting BI meeting copper in a few places.

 

[BoilerMan]

I have never seen any issues transitioning between two metals (copper to iron/steel) in a closed loop system. Avoid ANY galvanized (zinc) in the system though, copper to galvanized will give you trouble in short order.

As a rule I always thread copper into the ferrous metal, never thread copper over ferrous metals. I have seen those joints leak over time, my theory is that the softer copper stretches with heat/cool cycles. In short I only stock copper male threaded adapters. Same rule for brass, always into iron. This is only for closed loop systems, in any open system (potable water) brass is used for any transition, which there shouldn't be ferrous metals in open systems.

TS

 

[weiland13]

This should help.

http://www.engineersedge.com/galvanic_capatability.htm

 

[BoilerMan]

Yes but according to the chart the solder will corrode through the copper....................real world experience. I have disassembled many cu/fe joints in hydronic systems that were leak-free and had been in place 50+ years. All of them were copper threaded into iron.

And don't even think of using dielectric unions, even seen one of those in service?? Me neither.

TS

 

[sir james]

Am I reading this right?
Are you planning on using pex for propane?

 

[kuribo]

No, I am using retasked propane tanks for water storage. There is no propane in the equation.