Recommended max. pump suction flow velocity for viscous fluids.
Avoid higher velocities in suction pipes. Higher velocities increases pressure loss in pipes and the pumps may start to cavitate. For viscous liquids - as a rule of thumb - the suction velocities in front of pumps should be below:
|Pipe bore||Viscous Liquid Suction Velocity|
These values depends a lot on the fluid pumped. More about viscosity and viscosities for different fluids: