De-Zinctification in Bronze Valve bodies

[Kris Ericsen]

I'm seeing more and more of this curious corrosion condition on Bronze Valve bodies in Alaska. I've heard it described as "De-Zinctification" but don't know much about it.

The corrosion appears to be coming directly out of the bronze casting; and seems not to be related to electrolysis, water leaks, exposure to chemicals or any other unusual factors.

I'm seeing this in new homes built under normal, typical conditions. overseen by Municipal Inspectors and connected to City water in newer subdivisions.

The subject photo home was plumbed in PEX with the vertical Panel type Manifold and UFER foundation Re-bar primary Electrical grounding. The isolation valve is above the Gas Water Heater in the garage with a transition to PEX at a point 18" inside the house.

It's possible that the small corrosive growths were there before; but obscured by other, larger corrosive expressions at soldered joints or part assembly junctures on older work.

I'm wondering if the cause is poor quality imported valves, changes in the way these components are made, or different metalurgical processes having an effect on these products.

Anybody know whats up with this?

[John Kogel]

My guess is poor quality, castings purchased from off-shore suppliers with little pinholes in them.

[Bruce Adams]

This is the junk that we are getting from China. Poor quality. I recommend replacing with a quality valve.
Bruce

[Mike Clarke]

I noticed last time I was at the big home center here, all the valves, PVC fittings, etc was made in china

Tag said American valve company, NC
Was made in china !

Products with wiring from china, many have too much lead
Toys from china, too many tested had high level lead
I wonder if many of these china made plumbing parts have too much lead and if leaching into the water ?

[Ken Zapen]

I think you are looking too deeply into this. It looks like that packing nut was leaking at one point and the deposits are actually mineral deposits that have evaporated.

FYI Bronze does not de-zincify, but yellow brass does. :) Also, de-alloying of any kind typically occurs on the inside of the fitting, not the outside. If it makes its way all the way to the outside the fitting will shatter due to the embrittlement caused by the de-alloying process. Metals that have been de-alloyed typically have a porous, sponge like structure. They will shatter or disintegrate if disturbed.

[Grace Guer]

[QUOTE=Kris Ericsen;146906]I'm seeing more and more of this curious corrosion condition on Bronze Valve bodies in Alaska. I've heard it described as "De-Zinctification" but don't know much about it. The corrosion appears to be coming directly out of the bronze casting; and seems not to be related to electrolysis, water leaks, exposure to chemicals or any other unusual factors. .......
Anybody know whats up with this?[/I got a similar problem, what's this that appears to be white corrosion at a supply system shutoff valve servicing the water heater (see pict). Thirteen year old home in St. Charles County MO]

[David Bell]

[quote=Kris Ericsen;146906]I'm seeing more and more of this curious corrosion condition on Bronze Valve bodies in Alaska. I've heard it described as "De-Zinctification" but don't know much about it. The corrosion appears to be coming directly out of the bronze casting; and seems not to be related to electrolysis, water leaks, exposure to chemicals or any other unusual factors. .......
Anybody know whats up with this?[/I got a similar problem, what's this that appears to be white corrosion at a supply system shutoff valve servicing the water heater (see pict). Thirteen year old home in St. Charles County MO]
I would guess that the anode in your water heater is toast.

[Bruce Adams]

[quote=Grace Guer;148757]
I would guess that the anode in your water heater is toast.

I would like for someone to explain to me how the anode rod would have anything to do with this. As the manufactures of the water heaters say there is no way that this can be from the anode rod. This is from the cheap junk that is coming out of China. Replace the Valve with a quality valve from a good supplier. That is not Lowes or Home Depot. Watts still makes a good quality Valve. There are other good companies out there. Stay away from American Valve or Chicago Valves and many other companies with U.S. names that there products are made in China They are junk.
Bruce Adams