On Wednesday, 13 March 2019 12:59:32 UTC, wrote:
On Wednesday, 13 March 2019 08:08:49 UTC, harry wrote:
On Tuesday, 12 March 2019 18:52:04 UTC, tabby wrote:
On Tuesday, 12 March 2019 07:41:21 UTC, harry wrote:
On Monday, 11 March 2019 17:37:33 UTC, misterroy wrote:
What could have caused the heating pipe to corrode so badly that it failed? It was next to an external wall and lagged. The are a couple of lengths of the pipe lying outside the building unused for the same 6 years, other than the threaded ends, they look new.
image https://drive.google.com/open?id=1o8...cqBdRGYatmQb6R

If it is attached to copper pipe elsewhere in the system, zinc and copper are perfect for galvanic action.
Depends too on the quality of the water in the system. Inhibitors are available.

Is there some way to stop this corrosion in a CH system using copper pipes & a galvanised steel cylinder/tank?


NT

The way galv tanks are protected is with a magnesium "sacrificial anode"
Has to be replaced every few years as it "rots" away instead of the tank.

https://en.wikipedia.org/wiki/Cathodic_protection

http://www.waterheaterrescue.com/Lon...er-anodes.html

thanks, useful. Galv tanks are so much cheaper than copper.


NT

There's the cost of the sacrificial anode replacements to consider too.