Page 424 - Bürkert

Diagram Flow/Velocity/DN

Selection Help – Flow Velocity Considerations
Depending on the sensor type, the right flow rate has to be chosen to get the best accuracy. The higher the flow velocity, the lower the meas-
urement error, but the higher the pressure loss. The following chart will help you find the correct fitting diameter for your application depending
on flow velocity and sensor technology. Pipes for fluids similar to water are generally designed for an average flow velocity of approx. 2 to 3
S030 Fittings S030 Fittings
m/s or 6-10 ft/s.
Example:

• Flow: 10 m /h
3
• Ideal flow velocity: 2... 3 m/s

For these specifications, the diagram indicates a pipe size of DN40 [or DN50 for (*) mentioned sensor-fittings]

Flow rate of fluid
Not recommended
3
gpm m /h
1000 l/min 200
3000
500 2000 DN65
100
DN50 (DN65)*
1000
200 50 DN40 (DN50)*
500
100 DN32 (DN40)*
20
DN25 (DN32)*
50 200 DN20 (DN25)*
10
100 DN15 (DN15 or
20 5 DN20)*
50
10
2 DN08
5 20
1
DN06
10
2 0.5
5
1
0.2
0.5 2
0.1
1
0.2 0.05
0.5
0.1
0.02
0.05 0.2
0.01
0.1 0.3 0.5 1 3 5 10 m/s
0.3 0.5 1 3 5 10 30 fps
Flow velocity

* for following fitings with:
• external threads acc. to SMS 1145
• weld ends acc. to SMS 3008, BS 4825/ASME BPE or DIN 11850 Series 2
• Clamp acc. to SMS 3017/ISO 2852, BS 4825/ASME BPE or DIN 32676

423