Question re: multi-stage lubrication pump
 

Good day, hopefully someone with knowledge can answer a question.

On a turbine engine, in a multi-stage lubrication pump - let's say you have a pump with one pressure stage and 4 scavenge stages driven from one drive (shaft) and one of the scavenge stages or elements seizes up, does the whole pump fail (at the pump drive shear point...?) or is there a separate shear point between that failed element or stage gear element and the drive shaft so the pump continues to operate minus that one scavenge stage?

Wordy, hopefully phrasing the question so it can be understood.

Thanks much - TM

I would say it will fail completely, which is good because not all engines have diff press sensor(s) for press-scav side to notice problem. If pump stops, you get low press warning and you will shut down engine. If pump runs only partially you may ruin whole engine or greate other oil related problems before you notice anything wrong with it.
Scavenge side is very important part of the pump on jet engines.