Copper

Copper is used extensively in commercial, industrial and institutional buildings. And used to be used in residential, so if you are repairing or renovating in a house you may run into copper tube for drainage and water lines. I always adapt over to pex for waterlines or ABS for drainage lines.

copper tube comes in many sizes. For water lines the sizes range typically from ½ to 4 inch in size. For drainage you will see lines between 1 ¼ and 4 inch. In new construction anything over 2 inches will not be used for drainage, because cast iron is cheaper and takes less labor to install. In cases where waterlines need to be larger than 4 inch galvanized pipe is used. Black iron pipe can not be used since the fresh water will rust out the pipe, except in closed heating systems where the oxygen has left the water and the water is treated every year with rust inhibitors.

Each length of copper is rated for different purposes. The ratings for copper tube are DWV (drain waste and vent), Type M (residential and small commercial), Type L (Commercial, heating), Type K (corrosive areas, industrial), Type H (hospital oxygen lines)

Copper Fittings

The copper fittings slip over the tube and need to be cleaned, fluxed and soldered to join the copper together. The fittings used for water lines are copper pressure fittings (more room for solder) and the fittings used for drainage are either brass or copper.

copper tube and fittings can not touch and metal. If this happens your copper will get pin hole leaks from electrolysis. This is an electrical charge or current, this current will very quickly erode the tube. You would be amazed at the number of pin holes that will develop in just 3 to 6 months. Dielectric fittings need to be used in cases where this can not be helped.