: We are helping our friend find definitions needed for : school and are having problems.: Please help…..: 1 Recirculation mainAre you sure you dont mean reticulation main? If its recirculation main then my guess is that it refers to a hot water main pipe in a recirculating system; where water circulates (via pumping or via convection) throughout the system. Cooler water returns to the heating source so as to keep the water hot at any take off point.: 2 Recirculation valveI don�t think this term exists but I may be wrong.: 3 Recirculation pumpIn a pumped circulation system (eg. For hot water) this is an inline pump that keeps the water circulating throughout: 4 Direct siphonageThis is Self-Siphonage. In laymans terms, a solid column of water (completely filling a pipe) will tend to suck the water-seal of a trap out via its own momentum.: 5 Vent stack : 6 Stack ventStack Vent is the term. The part of the stack that extends beyond the highest fixture to atmosphere.: any assistance would be greatly appreciated.
