In an ejector system, how is the length of run measured?

The length of run in an ejector system is measured from the pump outlet to the highest point. This measurement is crucial for evaluating the system’s performance and ensuring that it can effectively move waste or sewage to the designated discharge point. By starting from the pump outlet, you capture the total vertical lift and horizontal distance that the wastewater must travel before reaching the highest point in the system.

When measuring this length, it is important to account for all friction losses and potential lift that the ejector system has to overcome. The highest point is significant because it indicates the maximum elevation the wastewater must reach, influencing the pump's horsepower needs and overall system design. Furthermore, adequate pumping capacity is vital for the effective operation of an ejector system to prevent backflow and ensure proper drainage.

In contrast, the other options focus on different points in the plumbing system that do not accurately reflect the critical distance impacting the ejector's operational efficiency. For example, the vent line and street connection are not relevant to the specific hydraulic measurements needed for performance assessment.