What is copper and why does it turn green?

Copper is a soft and malleable naturally occurring metal which is red-brown in colour. It has high thermal properties and is excellent at conducting electricity. It is known as a transition metal, as it has multiple oxidation states and is able to form a stable compound with a number of different elements.These are some of the reasons why copper pipe is so popular in the construction industry. This versatile metal is commonly used in home plumbing and heating systems because it is resistant to corrosion in many underground environments and is very strong, meaning it is not likely to fail.

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Why copper turns green

Exposure to oxygen in the air, known as ‘oxidation’, is what turns copper green. Environmental conditions such as temperature, humidity and exposure to air, water and other airborne pollutants control the rate at which copper oxidises and changes colour.

The oxidation of copper has many benefits. It provides a pleasing appearance and protects the underlying metal from corrosion. It can also increase the strength of the material.

On the flip side, oxidation reduces the conductivity of the material which increases its electrical resistance and likelihood of failure through overheating. It can also reduce the purity of the material.

Choosing copper pipe

Many copper pipe suppliers will be able to advise on the most appropriate pipe for your application.

There are three grades of copper pipe available from which to choose:

– Type K, which is a rigid or flexible copper pipe that is commonly used for mains water

– Type L, which is a rigid or flexible pipe generally selected for branch water supply lines

– Type M, which is also designed for branch water supply lines, but is only available in rigid form.

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Copper pipe is a long-lasting, robust and reliable material that is commonly used in heating and plumbing applications in both domestic and industrial environments. It is essential that you select the most appropriate type of pipe for your intended purpose in order to maximise its effectiveness.

Niru Eilish

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