Fluid_Flow_Rules_of_Thumb_for_Chemical

Fluid F l ow

7

RecommendedVelocities

Here are various recommended flows, velocities, and pressure drops for various piping services.

Sizing Cooling Water Piping in New Plants Maximum Allowable Flow, Velocity and Pressure Drop

MAINS

LATERALS

Flow GPM

Vel.

Flow GPM

AP

Vel.

AP

Pipe Size in.

ft/sec, f t / lO0'

ft/sec,

ft/100'

7O

3.04 3.53 4.22 4.17 4.48 5.11 5.13 5.90 6.23 6.67 7.82 8.67

2.31 2.22 1.92 1.36 1.19 1.23 1.14 1.16 1.17 1.17 1.19 1.11

100 200 500 900

4.34 5.05 5.56 5.77 6.10 6.81 7.20 7.91 8.31

4.47 4.29 3.19 2.48 2.11 2.10 2.10 2.09 1.99

3 4 6 8

140 380 650

Sizing Steam Piping in New Plants Maximum Allowable Flow and Pressure Drop

1,100 1,800 2,200 3,300 4,500 6,000

1,500 2,400 3,100 4,500 6,000

10 12 14 16 18 20 24 30

Laterals

Mains

Pressure, PSIG Density, #/CF

600 0.91

175 0.41 0.70

30

600 0.91 0.70

175

30

0.106

1.41 0.40

0.106

0.50

0.30

AP, PSI/100'

1.0

11,000 19,000

Nominal Pipe Size, In.

Maximum Lb/Hr • 10 3

7.5

3.6 7.5

1.2 3.2 8.5

6.2

2.7 5.7

0.9 2.5 6.6

3 4 6 8

15 40 76

12 33 63

Sizing Piping for Miscellaneous Fluids

21 42 76

16 32 58 87

18 32 50 70

14 25 39 54 78

t0 12 14 16 18 20

130 190 260 360

108 158 217 300

100 ft/sec 60 ft/sec

Dry Gas Wet Gas

115 155 220 300

117 166 227

150 ft/sec 100 ft/sec 100 ft/sec Max. velocity 0.3 mach 0.5 psi/100 ft 0.5 ft head total suction line

High Pressure Steam Low Pressure Steam Air Vapor Lines General

100 130 170

9

. . .

101 132

. . . . . .

. . . . . .

Note: (1) 600PSIG steam is at 750~ 175PSIG and 30PSIG are saturated. (2) On 600PSIG flow ratings, internal pipe sizes for larger nominal diameters were taken as follows: 18/16.5"; 14/12.8", 12/11.6", 10/9. 75": (3) If other actual I.D. pipe sizes are used, or if local superheat exists on 175PSIG or 30 PSIG systems, the allowable pressure drop shall be the governing design criterion.

Light Volatile Liquid Near Bubble Pt. Pump Suction Pump Discharge, Tower Reflux Hot Oil Headers Vacuum Vapor Lines below 50 MM Absolute Pressure

3 - 5 psi/100 ft 1.5 psi/100 ft Allow max. of 5%

absolute pressure for friction loss