Which type of vent connects directly to a fixture drain and terminates above the roof level?

An individual vent is specifically designed to connect directly to a single fixture drain and provides a path for gases to escape to the atmosphere above the roof level. This type of vent ensures that the fixture can operate properly by preventing negative pressure in the drainage system, which can cause issues such as siphoning traps.

By terminating above the roof, the individual vent effectively allows any gases to disperse safely into the environment, maintaining the overall efficiency of the plumbing system and protecting against odors and potential health hazards. This function is critical in plumbing design to ensure that each fixture is adequately ventilated and can drain effectively without back pressure.

Other types of vents have different applications; for example, a main vent serves a larger area, common vents are used for multiple fixtures that share a drain line, and revents are designed to serve as secondary vents for fixtures connected to a common sewer connection. Each type has a distinct role in the plumbing system, but the individual vent is uniquely suited to ventilating a single fixture.