Installing 3-way

"Transition couplings" (really intended to transition from one pipe material to another) or "no hub couplings"(when going from ABS pipe to plastic 3-way valve) can be used to install a 3-way valve, allowing it to be removed or rotated in place at some point in the future.  It is essential to "set" the handle and face so that the inlet is in the
correct position.