How many bathtubs may be hooked up to a 2" vent?

The correct answer indicates that a 2-inch vent can accommodate up to 12 bathtubs. This is based on plumbing codes, which specify that the maximum number of drainage fixtures that can be connected to a vent is determined by the size of the vent and the type of fixtures being served.

In this case, a 2-inch vent is suitable for venting multiple bathtubs due to its ability to allow for adequate air circulation, which is essential for the efficient operation of the drainage system. The plumbing codes also consider factors such as the developed length of the vent and potential fittings that could impact the vent's performance, but for bathtubs specifically, the capacity is capped at 12 fixtures for a 2-inch vent.

The other numbers suggest capacities beyond what plumbing codes typically allow, reflecting a misunderstanding of the limitations imposed by vent size and fixture types. Therefore, recognizing that a 2-inch vent is capped at servicing 12 bathtubs is crucial for compliance with plumbing standards and maintaining an effective waste system.