The function of seal cages, or lantern rings installed in the centrifugal pump stuffing boxes, is to __________.

Official USCG Answer & Rule Citation

Correct Answer: Option C — distribute the sealing liquid within the stuffing box

Seal cages, or lantern rings, are positioned within the stuffing box to provide a channel for sealing liquid. This liquid acts as a lubricant and coolant for the packing, while also creating a positive pressure barrier to prevent air from being drawn into the pump during suction lift conditions.

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