The dezincification of brass...a lesson learned

[Cheese]

About 6 years ago I installed a Rinnai condensing, tankless water heater rated at 97% efficiency. It came with a condensate trap and a connection for a condensate drain.

When I originally plumbed the condensate drain I used a brass union along with a brass barbed fitting attached to a short section of PVC hose. That went to a condensate pump.

Yesterday I noticed some water on the floor underneath the Rinnai and decided to investigate. Here's what I found.

The brass coupling and the brass barbed fitting.

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In this photo you can see that one section/side of the barbed fitting is completely dissolved.

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Here's a good article if you're interested in more info.  [smile]
https://www.canada.ca/en/conservati...on-institute-notes/dezincification-brass.html

 

[Svar]

Condensate from water heaters is acidic.
I'm surprised (not really) you missed that when you carefully read [wink] the instructions  [poke]

 

[six-point socket II]

Incredible. Learned something new! Thanks for sharing!

Kind regards,
Olive

 

[deepcreek]

Wow!  That's crazy.

I have never seen anything like this.

I had always thought of brass as near bulletproof for water piping.

 

[DeformedTree]

Yeah, this was a major issue in parts of the country with PEX plumbing and similar systems. They started with Yellow brass and the system would fail.  Ensuring parts are made with Red brass looks to have resolved this, but is still gives me some pause for what to do in my house.  While the brass fittings have issues, I'm also not very confident in the plastic fittings holding up long term either for other issues, and additional pressure drops.  Plus what is to say you don't get a bum fitting/counterfeit fitting that then suffers dezincification.

 

[Cheese]

Yeah, this was a major issue in parts of the country with PEX plumbing and similar systems. They started with Yellow brass and the system would fail.  Ensuring parts are made with Red brass looks to have resolved this, but is still gives me some pause for what to do in my house.  While the brass fittings have issues, I'm also not very confident in the plastic fittings holding up long term either for other issues, and additional pressure drops.

Ya you nailed it with the yellow brass vs red brass. If the copper level is 85% or more you’re good to go. Less than that and you may have issues. So red brass has a higher content of copper while yellow brass has a higher level of zinc. I just bring this up for buyer beware issues.

Damnnnnnnn, this is the reason I always favor stainless. That’s never an issue.

 

[Michael Kellough]

Once upon a time when my house was heated with steam produced by an oil fired boiler I went down to the basement and immediately smelled oil, and the boiler was running. Switched it off and went to the site and found a big puddle of oil surrounded the installation. It was leaking out of a pin hole in a brass elbow in the supply line.

Maybe it was the result of a similar process? I had mixed feelings about the fact that the puddle of oil was inches below a big open flame yet didn’t ignite.

 

[Svar]

I had always thought of brass as near bulletproof for water piping.

It is for regular tap water. The failed fitting was used for heater condensate, which can have pH as low as 2 (acid). Only plastic or stainless should be used there.