Fluid Flow Velocities

Guidelines for the acceptable ranges of flow velocity for various fluids found in a sugar factory

Goodall
  Velocity [m/s]
Water for space heating 2 4
Water for boiler feed 3 6
Saturated steam 30 50
Superheated steam 50 100
Hugot
  Velocity [m/s]
Superheated steam 40 76
Saturated steam 24 37
Exhaust (wet/oily) 31 46
Bled vapour 37 49
Vapour under vacuum 46 76
Suction
Water 1 1.25
Juice 1 1.2
Syrup 0.5 1
Molasses 0.25 0.5
Massecuites 0.1 0.2
Delivery
Water 1.25 2.5
Juice 1.2 2
Syrup 0.75 1.25
Molasses 0.5 0.75
Massecuites 0.15 0.3
Lyle
  Velocity [m/s]
Water 1.22 2.44
Superheated steam 46 61
Dry saturated steam 31 40
Wet exhaust steam 21 31
Moderate vacuum water vapour 46 61
High vacuum water vapour 61 107
Babcock & Wilcox
  Velocity [m/s]
High pressure steam 41 61
Low pressure steam 61 76
Water general 2.54 3.81

From a source on the internet

Maximal velocity in pipes
Water m/s ft/s
Tap water (low noise) 0.5 - 0.7 1.6 -8.2
Tap water 1.0 - 2.5 3.3 - 8.2
Cooling water 1.5 - 2.5 4.9 - 8.2
Boiler feed water. suction 0.5 - 1.0 1.6 - 3.3
Boiler feed water. discharge 1.5 - 2.5 4.9 - 8.2
Condensate 1.0 - 2.0 3.3 - 6.5
Heating circulation 1.0 - 3.0 3.3 - 9.8
Steam m/s ft/s
Saturated Steam. high pressure 25 - 40 82 - 131
Saturated Steam. in special cases - 60 - 197
Saturated Steam. medium and low pressure 30-40 99 - 131
Saturated Steam. at peak load - 50 - 164
Steam / Water emulsion - 25 - 82
Oil m/s ft/s
Suction lines for pumps - 0.5 -1.6
Suction lines for pump (low pressure) 0.1 - 0.2 0.3 - 0.65
Discharge line for booster pump 1.0 - 2.0 3.3 - 6.5
Discharge line for burner pump - 1.0 - 3.3
Air m/s ft/s
Combustion air ducts 12 - 20 40 - 66
Air inlet to boiler room 1 - 3 3.3 - 9.8
Warm air for house heating 0.8 - 1.0 2.6 - 3.3
Vacuum cleaning pipe 8 - 15 26 - 49
Compressed air pipe 20 - 30 66 - 98
Ventilation ducts (hospitals) 1.8 - 4 5.9 - 13
Ventilation ducts (office buildings) 2.0 - 4.5 6.5 - 15
Exhaust gas m/s ft/s
Ducts at minimum load - 4.0 - 13
Stack at minimum load - 5.0 - 16
Boiler with one-step burner (on - off) 5.0 - 8.0 16 - 26
Boiler with two-step burner (high - low) 10 - 15 31 - 49
Boiler with modulating burner (3:1) 15 - 25 49 - 82
To keep the surface free from soot the velocity should always exceed 3.0 - 4.0 9.8 - 13
It is recommended that the maximum inlet velocities applied to control valves should be as shown in the tables below.
Gate Valve Size Liquid Steam or Gas
mm m/s ft/s m/s ft/s
15 - 25 9 30 120 400
40 - 50 7.5 25 90 300
65 - 100 6 20 75 250
150 - 200 6 20 70 225
250 - 400 4.5 15 55 175
Angle Valves Size Liquid Steam or Gas
mm m/s ft/s m/s ft/s
15 - 25 13.5 45 135 450
40 - 50 12 40 105 350
65 - 100 10.5 35 90 300
150 - 200 9 30 85 275
250 - 400 7.5 25 70 225

References