Massachusetts Plumbers Journeyman Practice Exam

What is the minimum computed velocity of discharge storm or sanitary drains shall be installed at?

1. One foot per second

2. One and a half feet per second

3. Two feet per second

4. Two and a half feet per second

The correct answer is: Two feet per second

The minimum computed velocity for the discharge of storm or sanitary drains is established to ensure that waste and stormwater move effectively through the piping system. A velocity of two feet per second helps to prevent the settling of solids and minimizes the risk of blockages, which is a critical consideration in plumbing design. This velocity also aids in scouring grease and debris from the pipe walls, promoting a healthier drainage system that functions efficiently over time. The specified velocity ensures that the flow is swift enough to handle varying volumes of wastewater or stormwater, which can fluctuate based on weather conditions and usage patterns. Hence, the two-foot per second standard strikes a balance between adequate flow and preventing problems associated with stagnant water or slow-moving sewage. This standard is backed by plumbing codes and best practices within the plumbing industry, maintaining the overall integrity and efficiency of the drainage system.