Pipe Size and GPM Chart

WATER FLOW THROUGH STEEL OR COPPER PIPE Steel or copper piping is generally sized for water flow that will result in a friction loss of approximately 2 feet of water per 100 feet of pipe length and a velocity of  7 feet per second or less. This chart indicates the flow in GPM that a pipe size can generally handle:

Pipe Size

GPM

½"

Up to 1.5

¾"

2 - 3.5

1"

4-7

1 ¼"

8 - 14

1 ½"

15 - 22

2"

23 - 40

2 ½"

41 - 70

3"

71 - 120

4"

121 - 250

5"

251 - 450

6"

451 - 700

8"

701 - 1200

Adapted from: HVAC Technician's Handbook , LAMA Books, www.lamabooks.com