Recommended sizes, flows, and velocities for copper tubing

Courtesy of Taco, Inc.

Nominal tubing size (inches)

Minimum flow

Maximum flow

gal/min

ft/s

gal/min

ft/s

0.5

-

-

1.5

2.1

0.75

1.5

1.0

3.5

2.3

1

3.5

1.4

7.5

3.0

1.25

7

1.9

13

3.5

1.5

12

2.1

20

3.6

2

20

2.1

40

4.1

2.5

40

2.7

75

5.1

3

65

3.0

110

5.2

3.5

90

3.1

150

5.2

4

130

3.5

210

5.6