Massachusetts Wastewater Practice Exam

Which valve position is typically the safest for a pump during maintenance?

1. Open both suction and discharge valves

2. Close the suction and open the discharge valve

3. Close both valves

4. Open the suction and close the discharge valve

The correct answer is: Close both valves

During maintenance of a pump, the safest valve position is to close both the suction and discharge valves. By closing these valves, you effectively isolate the pump from the system, which is crucial for ensuring safety during maintenance activities. This prevents potential hazardous situations such as backflow, pressure buildup, or leakage of fluids from occurring while technicians are working on the pump. It also minimizes the risk of exposure to any materials that may be within the system, thus protecting the personnel involved in the maintenance. Having both the suction and discharge valves closed ensures that the pump is completely isolated, allowing for safe access without the risk of unintended fluid movement. This position also helps in protecting the pump from damage that could occur if it were to be started while maintenance is being performed. In contrast, having any of the valves open carries the risk of fluid entering or exiting the pump, which can lead to accidents or equipment failure.