(1)
Tees may be extracted from the wall thickness of Types K and L copper tube used in a water distribution system, provided that
(a)
a tool specifically designed for the purpose is used,
(b)
the branch is at least one NPS smaller than the tube in which the tee is formed,
(c)
the end of the branch incorporates a means to prevent it from penetrating into the run and thereby obstructing flow, and
(d)
the joint at the tee is brazed with a filler metal having a melting point not below 540°C.