Massachusetts Plumbers Journeyman Practice Exam

What is the increase in vent diameter called, and how high below the roof surface should it occur?

1. Connector, two feet

2. Adapter, three feet

3. Reducer, six inches

4. Increaser, one foot

The correct answer is: Increaser, one foot

The increase in vent diameter, which is crucial in plumbing systems to facilitate proper venting and maintain air pressure, is indeed referred to as an "increaser." This term accurately describes the fitting used to transition to a larger diameter vent pipe, ensuring that the venting system can adequately handle the volume of air needed to prevent trap siphoning and facilitate drainage. Furthermore, the requirement that this increase occur one foot below the roof surface aligns with plumbing codes that aim to prevent the potential for rainwater infiltration and frost accumulation, which could impede vent function. By establishing this distance, it ensures that the vent is both functional and compliant with safety standards. The other options present different fittings or measurements that do not align with the established standards for venting pipe installation, indicating a misunderstanding of the plumbing specifications defined in the Massachusetts Plumbing Code and good plumbing practices.