If a plant needs to ramp up flow without changing system head, which pump arrangement is most appropriate?

If a plant needs to ramp up flow without changing system head, which pump arrangement is most appropriate?

• A. Parallel Pumps
• B. Series Pumps
• C. Pump Deadhead
• D. Pump Runout

Answer: (A)

To ramp up flow without changing system head, use pumps in parallel because they share the same discharge pressure and their flows sum. Each pump operates at the same head corresponding to the system demand; adding another pump simply adds its flow to the total, so the overall flow increases while the head stays roughly the same as a single pump would at that head. If pumps were placed in series, the same discharge flow would see a higher head, moving the operating point to a higher head and not increasing flow at the existing head. Deadheading a pump by closing the discharge valve would raise head but reduce flow to near zero, which defeats the goal. The term runout does not provide a reliable method to increase flow at a fixed head. So the arrangement that achieves the desired ramp in flow without changing head is parallel pumps.

To ramp up flow without changing system head, use pumps in parallel because they share the same discharge pressure and their flows sum. Each pump operates at the same head corresponding to the system demand; adding another pump simply adds its flow to the total, so the overall flow increases while the head stays roughly the same as a single pump would at that head. If pumps were placed in series, the same discharge flow would see a higher head, moving the operating point to a higher head and not increasing flow at the existing head. Deadheading a pump by closing the discharge valve would raise head but reduce flow to near zero, which defeats the goal. The term runout does not provide a reliable method to increase flow at a fixed head. So the arrangement that achieves the desired ramp in flow without changing head is parallel pumps.