Recommended sizes, flows, and velocities for steel pipe

Courtesy of Taco, Inc.

Nominal pipe size (inches)

Minimum flow

Maximum flow

gal/min

ft/s

gal/min

ft/s

0.75

1.8

1.1

4.0

2.4

1

4.0

1.5

7.2

2.7

1.25

7.2

1.6

16

3.5

1.5

14

2.2

23

3.7

2

23

2.3

45

4.6

2.5

40

2.7

70

4.7

3

70

3.0

120

5.2

3.5

100

3.2

170

5.4

4

140

3.5

230

5.8

5

230

3.7

400

6.4

6

350

3.8

610

6.6

8

600

3.8

1200

7.6

10

1000

4.1

1800

7.4

12

1500

4.3

2800

8.1