Figure 8-2.-Typical copper fittings.
types: K, L, and M. K has the thickest walls, and
Type L copper tubing is also available in either
M, the thinnest walls, with L’s thickness in
between the other two. The thin walls of copper
tubing are soldered to copper fittings. Soldering
allows all the tubing and fittings to be set in place
before the joints are finished. Generally, faster
installation will be the result.
Type K copper tubing is available in either
rigid (hard temper) or flexible (soft temper) and
is primarily used for underground service in the
water distribution systems. Soft temper tubing is
available in 40- or 60-ft coils, while hard temper
tubing comes in 12- and 20-ft straight lengths.
hard or soft temper and either in coils or in
straight lengths. The soft temper tubing is often
used as replacement plumbing because of the
tube’s flexibility, which allows easier installation.
Type L copper tubing is widely used in water
distribution systems.
Type M copper tubing is made in hard temper
only and is available in straight lengths of 12 and
20 ft. It has a thin wall and is used for branch
supplies where water pressure is low, but it is NOT
used for mains and risers. It is also used for chilled
water systems, for exposed lines in hot-water
heating systems, and for drainage piping.
8-2
