Is it ok in the engineering design concept?
In fact it is easier to get your before and after straight pipe distances on the suction side for mag meters which typically recommend 3d to 5d up and 1d down. You will need that short spool piece between (at the least) due to the high swirling action of the impellor.
But if the meter is a high pressure drop mechanical device (such as a disk or piston at high flow) it is not recommended unless available NPSH can cover the pressure drop
Above is a snippet.