Copper pipe(pipe fitting) is generally easily available and fairly easy to work with. It comes in various sizes and is sized by its outside diameter – 15mm, 22mm and 28mm are the most common sizes. Main runs and pipes feeding bath taps and the hot water cylinder are usually 22mm pipe. Pipes to all other taps are usually 15mm in diameter. The 28mm size might be used for some boiler pipes and sometimes for feeding the hot water cylinder (instead of 22mm pipe).
Copper pipe can be cut with a fine-toothed hacksaw or with a special pipe cutting tool. Care must be taken when using a hacksaw to cut the end of the pipe exactly square, and the cut must be filed smooth both inside and out. A pipe cutter tends to leave a burr on the inside of the pipe – this should be filed off or removed with the pointed reamer on the pipe cutter.
Copper pipe can be bent fairly readily but it must be supported during the process or it will kink. Smaller diameters can be bent by hand with the aid of a bending spring. This is a stiff metal coil of nearly the same diameter as the inside of the pipe. It is pushed into the pipe around the point where the bend is to be made and supports the pipe during bending. The spring should be compressed a little – by turning it – before attempting to with¬draw it. You need one for each size of copper pipe. Pipe can also be bent using a bending machine.