Selection Guide

29
Pipe
Size
Horizontal Supply and Return Mains Two-Pipe One-Pipe
1 oz. 2 oz. 3 oz. Risers
Undripped
Runouts
Supply
Risers
Runouts
& Valves
1"
Supply
56 79 111
Upfeed
56
34 45 28
Wet Return
Dry Return
700
320
1000
412
1400
460
Return
450
1-1/4"
Supply
122 173 245
Upfeed
122
75 98 62
Wet Return
Dry Return
1200
670
1700
868
2400
962
Return
990
1-1/2"
Supply
190 269 380
Upfeed
190
108 152 93
Wet Return
Dry Return
1900
1060
2700
1360
3800
1510
Return
1500
2"
Supply
386 546 771
Upfeed
386
195 288 169
Wet Return
Dry Return
4000
2300
5600
2960
8000
3300
Return
3000
2-1/2"
Supply
635 898 1270
Upfeed
635
395 464 260
Wet Return
Dry Return
6700
3800
9400
4900
13,400
5450
Return
–
3"
Supply
1160 1650 2330
Upfeed
1130
700 800 475
Wet Return
Dry Return
10,700
7000
15,000
9000
21,400
10,000
Return
–
3-1/2"
Supply
1740 2460 3470
Upfeed
1550
1150 1140 745
Wet Return
Dry Return
16,000
10,000
22,000
12,900
32,000
14,300
Return
–
4"
Supply
2460 3480 4910
Upfeed
2040
1700 1520 1110
Wet Return
Dry Return
22,000
15,000
31,000
19,000
44,000
21,500
Return
–
5"
Supply
4550 6430 9090
Adapted from the ASHRAE Guide.
6"
Supply
7460 10,550 14,900
For downfeed supply risers, use “Supply” figures above.
Pressure drop columns are in ounces per 100 f eet, equivalent length of
run. Equivalent length of run can be approximated as double the actual
length of pipe.
Total pressure drop for the entire system should not exceed one-half the
normal boiler-guage pressure. Supply and return mains must be sized for
a uniform pressure drop for each system.
To convert to pounds, divide above figure by 4.
To convert to Btu’s, multiply above figures by 240.
Pipe capacities are based on a nor mal pitch of 1/4” in 10 feet for two-pipe
steam, and 1/2” pitch in 10 feet for one-pipe steam. If pitch is increased to
2” in 10”, the runout capacities above may be increased by 20%.
The maximum lengths of fin-pipe listed above may also be increased by
20% if 2” pitch is used.
Type Size
Square Ft. per
Linear Ft.
@ 1 psi
One
Pipe
Two Pipe
Low Pressure
30 psi
8 oz.
150 psi
16 oz.
1 oz. 2 oz.
Maximum Length of Individual Run in Lineal Feet
S540 1-1/4" ips 6.30 10 18 25 52 90
S832 2" ips 5.70 30 60 85 190 300
C540 1-1/4" cop. 7.50 8 16 22 45 –
H5X 1-1/4" cop. 4.70 8 16 22 45 –
H6X 1-1/4" ips 4.10 10 18 25 52 –
STEAM CAPACITIES OF PIPING (Low Pressure, 1psig) “Square Feet, EDR”
* Made of schedule 40 seamed pipe
ELEMENT APPLICATION FOR STEAM
Maximum Runs. Lineal Feet of Fin-Pipe:
The following table indicates maximum normal runs of fin-pipe for steam systems. These runs in lineal feet are based on conservative velocities and the
rapid removal of condensate. Pressure drops in column headings are per hundred equiv alent feet of pipe.