Plumbing Basics. Plumbing Image Gallery. Your home's supply and drainage system must always be two distinct subsystems, with no overlapping. At the fixtures (bridges between the two systems), the air admitted by the vent stack and vent pipes keeps the traps sealed and prevents sewer gases from backing up through the drains. See more plumbing pictures. … How can chronic care management be integrated into home design? Chronic conditions, which are persistent and hard to …