In relation to the liquid being pumped, the water supply to the water seal on a pack pump should be how much greater than what's being pumped?

The correct choice indicates that the water supply to the water seal on a pack pump should be 5 to 10 PSI greater than the pressure of the liquid being pumped. This is important because maintaining an appropriate pressure differential is essential for preventing any backflow or leakage of the liquid being pumped into the water seal area.

By ensuring that the water supply pressure is sufficiently higher, it creates a barrier that helps protect the pump's internals from contamination and wear. This is crucial for the longevity and efficient operation of the pump since any ingress of the pumped liquid could lead to damage and reduced performance over time.

Additionally, if the pressure differential is too low, it may not effectively counteract the pressure of the liquid being pumped, potentially compromising the seal and leading to operational issues. Thus, the specified range of 5 to 10 PSI is both effective and practical for ensuring reliable pump operation and protecting the system's integrity.