Brass/Stainless/Mild Steel Galvanic corrosion in piping

[HelluvaEngineer]

This is not exactly an HVAC question, but one that I'm sure most experience HVAC engineers have run across.

This is a large CHP installation of an recip-piston engine. There are many temperature sensors throughout the 3 hot water circuits (intercooler, jacket water, building heating loop). The sensors are German and have 1/2" G-threads. (same as 1/2" BSP or BSPP). I have found mass produced adapters (BSPP to NPT) made of brass, or I can have custom stainless ones made.

The process fluid is 35% PG 65% water. Should I be concerned about galvanic corrosion with stainless sensors, brass adapters and mild steel piping?

 

[alinlis]

No matter what, there will be galvanic corrosion between the two dissimilar metals. There are some dielectric connections that can be made and then would work.

 

[HelluvaEngineer]

Right, but has practical experience shown it to be enough to matter? I doubt this would be the first HVAC-esque piping system to have a combination of mild steel, stainless steel and bronze.

 

[ChasBean1]

I'm not too familiar with issue among "mild" steel, stainless, and bronze, but galvanic corrosion presents itself moreso between Cu+3 and Fe-2 (metals of opposite properties) in electrolytic solutions.

With good water chemistry control, you will probably not see any issues for a long time.