What is the correct piping configuration referred to for venting a urinal and floor-supported trap?

The correct answer pertains to "common venting," which is specifically utilized when multiple fixtures, such as a urinal and a floor-supported trap, share a single vent. This method is efficient because it allows for the use of one vent stack to serve more than one plumbing fixture, minimizing the need for additional piping and reducing overall installation costs.

In this system, the vent serves to equalize pressure in the drainage system, preventing trap siphonage and allowing for the proper flow of wastewater. Common venting is particularly advantageous in situations where space and pipe availability are critical factors. It is designed to accommodate the drainage and venting needs of fixtures that are closely situated in relation to each other, like a urinal and the corresponding trap.

Understanding why other configurations are less appropriate begins to illuminate their differences. Individual venting would mean each fixture requires its own separate vent, which can lead to unnecessary congestion and increased material costs. Combined venting typically refers to systems where both drainage and venting functions are performed by the same pipe, which may not be adequate for maintaining air pressure and proper drainage for each fixture in this context. Meanwhile, common drain venting can be confused with common venting but specifically refers to an arrangement focusing solely on the drainage side,