×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Copper Pipe Corrosion/Erosion
5

Copper Pipe Corrosion/Erosion

Copper Pipe Corrosion/Erosion

(OP)
I am trying to determine why the copper piping in a residential hot water circulation system failed after only three years.  The failure occurred in an elbow just upstream of the recirc pump. (I have photos but don't know how to include them.) I don't believe there is anything unusual in the water, and it does not look like galvanic corrosion.

RE: Copper Pipe Corrosion/Erosion

3
Your problem sounds like cavitation, a form of erosion corrosion caused by the formation and collapse of bubbles on the elbows sirface.  It is very common on propellers and such.

Possible solutions to the problem: (1) reduce the speed of the fluid flow, (2) use a rubber coating to absorb the impact of the collapsing bubble, (3) go to a stainless steel elbow (but beware of galvanic corrosion).

RE: Copper Pipe Corrosion/Erosion

2
The temp of the system can affect the erosion corrosion rates, especially in soft waters, so check other similar configurations for the next leak.  You can upgrade with a cupro-nickel piece and not be concerned about galvanic corrosion, although galvanic corrosion will be unlikely anyway in domestic water even if you do use a stainless steel piece.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources