water pipe issue

[driverman]

Hi again, another one to wet your appetite. This has been seen on several different bollards around a particular caravan site. The site will be investigated at some point to establish exactly what is happening and why.
The Bollards have electric sockets, water meter + taps on them. Hopefully the photos are attached. As you can see the water pipe has been affected by something. Cheap piping has been ruled out. All the distribution circuits to the bollards are RCD protected as well as the sockets on the bollards.
I've got a sneaky feeling it could be..electrolysis somehow via the water, but not going through any RCD's. Is it possible? Any one had experience of this before?
i suppose could disconnect earthing t.o bollard, then see if any volts founds across pipe and neutral

 

[driverman]

But, they will also induce a current in any metalwork they run against, promoting the corrosion you see.

The thing is though..............these are sold / installed all over the country to the exact same spec. Problem is on just one particular site / installation.

 

[GB.Kayak]

The thing is though..............these are sold / installed all over the country to the exact same spec. Problem is on just one particular site / installation.

... I refer you to my earlier posts ... cold water pitting corrosion ... galvanic corrosion requires dissimilar metals and the metal that corrodes is the more reactive not less reactive material; copper appears at first sight here to be the least reactive metal ... unless it is in contact with gold or silver!

 

[alanl]

Have a read of what happens to canal boat hulls and fittings. It is common for non-protected copper alloys to corrode away to nothing.
From the first page when googling: "The most common casualty of galvanic corrosion is a bronze or aluminum propeller on a stainless steel shaft, but metal struts, rudders, rudder fittings, outboards, and stern drives are also at risk. The way we counteract galvanic corrosion is to add a third metal into the circuit, one that is quicker than the other two to give up its electrons. This piece of metal is called a sacrificial anode, and most often it is zinc. In fact, most boaters refer to sacrificial anodes simply as zincs."