If intake pressure drops below 140 kPa during relay pumping, what does the signal indicate?

If intake pressure drops below 140 kPa during relay pumping, what does the signal indicate?

• A. There is danger of cavitation
• B. The pump is damaged
• C. There is no change in operation
• D. Discharge pressure is too high

Answer: (C)

In relay pumping, suction pressure is monitored, but not every drop in intake pressure forces an automatic change in what the pumps are doing. If the intake pressure falls below 140 kPa, the signal is simply showing that the suction side is approaching the lower end of the acceptable range. It does not by itself require changing the pumping setup—the system is designed to continue operating with the current settings as long as overall performance (discharge pressure, flow, and other indicators) remains within limits. So the signal here is indicating no automatic change in operation. Cavitation risk or damage would typically trigger a different response or alarm, and would be addressed only if those conditions are actually indicated by the system.

In relay pumping, suction pressure is monitored, but not every drop in intake pressure forces an automatic change in what the pumps are doing. If the intake pressure falls below 140 kPa, the signal is simply showing that the suction side is approaching the lower end of the acceptable range. It does not by itself require changing the pumping setup—the system is designed to continue operating with the current settings as long as overall performance (discharge pressure, flow, and other indicators) remains within limits. So the signal here is indicating no automatic change in operation. Cavitation risk or damage would typically trigger a different response or alarm, and would be addressed only if those conditions are actually indicated by the system.