Water leg : See Leg, 7.

Example:


Taxonomy
compressed air, airline, air dryer, dryer, air treatment, The Twin, Twin-Tube, CAFT, compressed air dryer, filters, treatment equipment, moisture removal, filtration, equipement, first line, line defense, mechanical air, Compressed Air Filter.

Defination from the web:
Leg for compressed air lines is a unique air dryer and a first line defense against airborne contaminates. ... replaces installation of conventional water leg at base of compressed air take off pipe. zero pressure drop. extends life of air equipment. all in one unit ...