To provide an underwater pump usable for a drain pump equipment requiring a high pump head.
This underwater pump device is provided with a guide leg part 11 provided in a drain area 2, a lower stage underwater pump 4 arranged in the guide leg part 11 impossible to rotate around an axis of the guide leg part and possible to put in/out in the vertical direction thereof, and an upper stage underwater pump 4A arranged in series to the lower stage underwater pump 4 by placing it over the lower stage underwater pump 4 impossible to rotate around an axis of the guide leg part 11 and possible to put in/out in the vertical direction thereof. A lower flange 44 and an upper flange 45 of both the underwater pumps 4 and 4A are provided with semi-circular engaging recessed parts 46, 46, etc., to be removably engaged with guide palls 11A, 11A, etc., as structural members of the guide leg part 11 freely to slide.
KATO TAKASHI
OGAWA YOSHINOBU