The most recent Hydraulics Institute Standard I have seen gives for vertical pumps with piggyback mounted motors of 5 feet or less height at 710 RPM a displacement limit of 5 mils peak-to-peak at the top motor bearing (Fig.77). For vertical non-clog pumps the limit is about 8 mils p-p at 710 RPM for 5 feet or less height (Fig. 78). The corresponding vibration velocity limits are about 0.2 in./sec. for both cases. Both cases are for non-rigid structures.
