A tale and trail of 2 fluids hot rod

hr

Here are two pipe samples from hydronic systems. Both about 2 years old. I disassembled the system on the left (1/2" nipple) today. The PH read 9.3 it was filled with a Fernox CP-3 blend of corrosion inhibitor. A very thin (protective)film layer is on the pipe wall.

The 1" nipples were on a system that had a new boiler installed, by me :), was flushed and filled with water and a hydronic anti freeze mixture blended with well water from the tap.
In less then 2 years time the fluid ph dropped to 5.8 ph. (Non barrier tubing in a radiant floor application.) The steel nipples had started to disenegrate and leak at the threads. Under the barnacles is where you generally find the greatest amount of metal removed and generally where pin holes will form. Fluid that goes bad like this can even dealloy metals like brass (dezincification), and appear as pin holes in the wall of ball valves or other brass components. Sometimes dismissed as sand hole in cast brass components.

hot rod

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=144&Step=30">To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"</A>

Earthfire

corrosion?

did the ph drop and start the corrossion or did the oxygen coming thru the non-barrier pex kill the additive package and jump start the corrossion.