The characteristic curve of the vortex pump is similar to that of the centrifugal pump, but it is more steep, its flow rate is small, but the head is big, but the efficiency is not high. Side clearance of the vortex pump (that is, the gap between the impeller and the cover plate) can not be too large, otherwise it will significantly reduce the efficiency, so this pump can only transport relatively pure liquid.

Vortex pump pressure and flow of the calculation formula is as follows: H = Phi u l /2g; Q=cF, type U -- circumferential velocity of the impeller; coefficient, phi, from 3.5 to 4.5; F channel cross-sectional area; C - groove liquid flow velocity, approximate take c=u/2 or (0.55 to 0.65 U). The impeller blade is generally 24 to 60.