Copper Pipe is one of the preferred pipes for long term applications because of its corrosion resistance, lightweight and tensile strength properties. There are different standards of the pipes which correspond to different grades. The wall thickness is considered in grading the pipes. The different grades correspond to different usages as well. There are basically two categories; the soft copper pipe and the hard copper pipe. The soft copper pipes are easy to be bent without some pipe bending tools. The hard copper pipes need some kind of pipe bending tools because they are harder and stronger. The difference is indicated by the coloring of the print on the pipe. There are type K, L, M and DWV types. Each has a color coding. They are green, blue, red and yellow respectively.
The copper pipe grading helps the workers to identify them. If the pipe has no pressure rating to determine the pressure containment capacity, then it could not be used for water supply lines. Therefore, the DWV is not used in water lines. Some of the pipes are stronger and more corrosion resistant than others. The K type or the green type is used to draw lines underground. It could be buried without accommodating much damage. There are different makes of the pipes as well. There are cold drawn copper seamless pipe and the hot rolled welded pipe. The application dictates which type and make is appropriate. The prices of type K copper pipe are usually higher than the other grades due to its improved mechanical properties.