# Pump water flow velocity recommended values

### What is the recommended velocity for water flow in pipes ?

Section summary
1. Water flow velocity in pipes at pump discharge
2. Water flow velocity design recommendations
3. Water velocity in pipes calculation

## 1. Water flow velocity in pipes at pump discharge

This page is giving references to design pump and piping to make sure the velocity of water is reasonable.

When designing or troubleshooting an existing water pumping system it is important to check what is the velocity of water in the pipe at the outlet of a pump. Indeed, if the flow is too high, then the pressure drop will be high in the system leading to a lot of loss of energy - and thus money - for the pump operator. If the flow is too low there may be other issues such as pipe fouling.

## 2. Water flow velocity design recommendations

The following velocities at the discharge of water pumps are recommended, depending on the pipe diameter :

 Pipe Diameter Water suction flow velocity recommended Inches mm m/s ft/s 1 25 1 3.5 2 50 1.1 3.6 3 75 1.15 3.8 4 100 1.25 4 6 150 1.5 4.7 8 200 1.75 5.5 10 250 2 6.5 12 300 2.65 8.5

## 3. Water velocity in pipes calculation

The velocity of water in pipe can be calculated with the following formula :

u=Qv/(π*D2/4)

With :

u = water flow velocity (m/s)
Qv = water volumetric flowrate in pipe (m3/s)
D = pipe diameter (m)