The leakage of air into the pump casing by way of the packing gland of a condensate pump is prevented by __________.

Correct Answer: Option A — a water seal line to the packing gland

Condensate pumps operate under a vacuum at their suction. To prevent atmospheric air from leaking inward past the shaft packing and deaerating the condensate, a positive pressure water seal line supplies high-pressure condensate to the lantern ring.