Subject: Pinhole leaksRe: Copper pipework - Pinhole corrosion

From: [email-masked] (Dfru)
Date: 5 Oct 1995 00:55:03 -0400

I too am quite interested in this subject, and would be most interested in
the responses. 

I have done some research on the subject. If the piping is not properly
reamed, turbulence downstream from the unreamed joint can cause pinhole
leaks over time. This is most commonly a problem where you have a
recirculating domestic hot water system. The continuous flow in the system
accelerates appearance of the problem.

---

From: [email-masked]
Date: 5 Oct 1995 13:20:16 GMT

>   [email-masked] (David Thompson) writes:
>  Can anyone offer informed comment on the latest research or opinion relating
>  to the causes of random pinhole corrosion of copper pipework in hot and cold
>  water systems? 
>  
 snip
I've found that often this type of corrosion is localized galvanic corrosion
caused by bit of iron/steel from upstream pipe landing on the copper
and causing a local cell to form.  I recall one instance where heat pumps
were installed close to power supply transformers; the electro-magnetic field
caused galvanic corrosion at the pipe-to-brass fittings, then the resulting
rust particles traveled downstream and landed on the small copper heat exchange
tubes (holding freon).  Small pinhole leaks developed on the small copper
tubes and the heat pumps became boat anchors in rapid fashion!

Good Luck