Causes of Copper Corrosion in Plumbing Systems
FR/R0007
March 2003

This review is the seventh in a series of FWR Reviews of Current Knowledge (ROCKs). Each focuses on a topical issue in the water environment area and provides concise, readable, scientific and technical information on the subject. They are intended to facilitate a wider understanding of the issues involved and to promote informed opinion about them.

The review is intended for anyone with an interest in the design or the installation of water supply systems using copper pipes or hot water cylinders. It is relevant to plumbers, water industry staff, architects and property owners.

It covers both hot and cold water supplies inside buildings, but not central heating systems.

Copper pipework, copper cylinders and copper alloy fittings have evolved to become the most widely used materials for plumbing systems. This is due to their properties of ease of use, corrosion resistance, mechanical strength and resistance to external penetration by liquids and gases, and ability to convey water without tainting it. However, internal corrosion by the conveyed water can occur in certain circumstances. The review describes:

• Problems that can occur inside the pipework and fittings of water supply systems made of copper and copper alloys (such as brass);
• How to identify the cause of problems when they do arise; and
• How problems might be avoided.

The review starts with a brief history of the use of copper and copper alloys in water supply applications. This is followed by a general overview of copper corrosion processes before describing the more detailed mechanisms of cuprosolvency, 'blue-water' problems, and the pitting corrosion of copper pipes, fittings and cylinders. The review concludes with information on the corrosion of brasses, gunmetals and solders used in plumbing systems.

There is a glossary of chemical terms and a list of 17 individual references. The total length is 34 pages (A5 size).

Copies of the report are available from the Foundation, price £10.00, less 20% to FWR members, or as a printable download in Adobe Acrobat pdf format.