Contact US

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!

*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

Embedded Copper tube repair Method

Embedded Copper tube repair Method

Embedded Copper tube repair Method

Hello all,
We have a 1” diameter copper (ASTM B88 Type K) line embedded in mass concrete that is part of a Piezometer system that is not holding pressure in a hydro dam project.
Prior to concrete placement it was tested and held a test pr of 290psi, but post concrete placement the pressure quickly falls to 125psi, then gradually to 0.
Total length is about 30 meters, with 6 nos of 1" elbows - so we are expecting the leak somewhere around first 15 meters.
As this is embedded no way knowing where the leaks are - so looking for an expertise, suggestions or experience in dealing such situation

RE: Embedded Copper tube repair Method

Corrosion! You probably have corrosion in the tubes which is causing the pressure drop. Try using a borescope to view the inside of the pipe to check for this. Embedding copper in concrete is not a great idea.

RE: Embedded Copper tube repair Method

Hi Ron - it is new construction, just installed. Yes we are getting a boroscope to check inside.

RE: Embedded Copper tube repair Method

If it is mechanical damage installing a plastic lining may be your best option.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Embedded Copper tube repair Method

I'm guessing that during concrete placement or curing, (at least) one of the joints and/or the bottom cap came loose.

What pressure range is actually required for the use of the piezometer system? Water exerts a pressure of ~0.43 lb/in2 per foot of static pressure, so even 100ft (~30m) of head should only need to resist ~43 psi, and I would expect the concrete surrounding the pipe to provide that easily.

I would at least look into the cost to abandon the pipe and install another instrument to compare against the potential cost of rehabilitation/repair measures.

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! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close