Steam Pipe Sizing

Saturated Steam Only

INITIAL PRESSURE 10 psig 15 psig 125 psig 150 psig 225 psig 250 psig 285 psig
Delta P, psi/100 ft. 0.25 0.5 1 1 2 2 2
PIPE SIZE Steam Flow (lb/hr)
3/4” 22 30 90 105 140 160 165
1” 40 55 155 170 280 295 300
1-1/4” 90 115 340 370 620 650 680
1-1/2” 140 180 530 570 960 1010 1060
2” 265 370 1080 1170 1945 2040 2100
2-1/2” 410 600 1780 1920 3205 3360 3500
3” 800 1110 3250 3520 5865 6160 6400
4” 1500 2350 6890 7440 12400 13000 24000
6” 4600 7130 20900 22600 37670 39500 42000
8” 9600 14800 43500 47050 78445 82340 85000
10” 17500 30000 79400 85860 143145 150250 155000
12” 46000 127500 137300 229745 241165 250000

Notes on Pipe Sizing:

Flow rates are determined using Sch 40 Carbon Steel pipe.

Steam pipe is sloped in the direction of flow, flow of condensate does not inhibit steam flow.

Velocities herein typically do not exceed 10 fps (non-industrial applications – for industrial applications size piping at higher pressure drops and velocities of 30 to 80 fps, but be wary of noise and internal pipe erosion).