Massachusetts Wastewater Practice Exam

Is it recommended to throttle a pump using the suction valve?

1. True

2. False

3. Only in emergencies

4. Only in specific scenarios

The correct answer is: True

Throttling a pump using the suction valve is not recommended as a standard practice because it can lead to various operational issues. The primary intention of a suction valve is to allow or restrict the flow of liquid into the pump, while throttling is generally better accomplished on the discharge side of a pump. When a suction valve is throttled, it can cause cavitation, a phenomenon where vapor bubbles form and collapse in the pump casing, leading to damage and reduced performance. Furthermore, manipulating the suction valve can interfere with the pump's operation and efficiency, leading to potential overheating and operational imbalances. Typically, adjustments to maintain desired flow rates should be made through the discharge side to ensure the pump operates within its optimal range without compromising its integrity. Therefore, while some might consider it acceptable under certain conditions, it is generally advised to avoid using the suction valve for throttling in routine operations.