What type of venting system catches drainage from another fixture?

The wet venting system is designed to handle drainage from multiple fixtures while allowing venting, which helps to maintain proper air pressure in the drainage system. In a wet vent, one pipe serves the dual purpose of both venting the drainage and conveying the waste from fixtures, such as sinks or toilets. This is particularly useful in situations where plumbing codes permit the use of one pipe for both functions, effectively conserving space and material.

Wet venting is often used in systems where fixtures are close together, allowing the drain from one fixture to assist in ventilating another fixture nearby. This setup is advantageous because it reduces the number of pipes required in a plumbing system and minimizes potential points of failure.

In contrast, a stack vent primarily serves the purpose of ventilation and does not typically carry waste from a fixture, while a dry vent cannot carry liquids and is solely for venting purposes. Point venting does not convey drainage from other fixtures, making wet venting the most appropriate choice for the question regarding a venting system that catches drainage from another fixture.