In some pumps, specially for big dia. top suction / discharge pumps using heavy springs , there is a tendency for the pumps to lift up
( sensor readings reported at site ).
Also we should not forget the WNC case when the line is empty but spring is unlocked ( starting of pump , maintenance etc. ), in that case an over designed spring will cause a lot of upward lifting force on the pump nozzle.
In our case the reducers are located at the top elbow approx. 4-5 m vertically up from the pump nozzle. This is quite normal as most vendors require straight spool pieces of pipe before connection to the pump nozzle.