2.2-2
2
Pipe Sizing
Installation
Instructions
EXAMPLE
(Refer to Fig 2)
IMPORTANT: If exact length is not on chart, use next longer
length. Select the size of pipe that shows at least as much
capacity as needed for each piping section.
a. Section A to B of pipe must supply the complete gas
load of 1,500,000 BTUH for the entire building.
Looking at the 5 PSIG sizing chart, the size of pipe
used in conveying gas would need to be sized at 1
inch diameter pipe. Note that even though furthest
distance from first stage regulator to appliance is 230
ft., we use the 250 ft. length.
b. Section B to C must supply the load of 1,000,000
BTUH. Select 3/4 inch pipe for Section B to C.
c. Section C to D must supply a load of 750,000 BTUH.
Select 3/4 inch pipe for Section C to D.
d. Section D to E must supply a load of 500,000 BTUH.
Select 1/2 inch pipe.
e. Sections E to F must supply 250,000 BTUH. Select
1/2 inch pipe.
f. Sections B to C must supply 500,000 BTUH. Use 1/2
inch pipe.
g. The final section, G to H, needs only 250,000 BTUH
for gas usage. This section would use 1/2 inch pipe.
Fig. 2
EXAMPLE
Perform pipe sizing for building.
Total heat load is 1,500,000 BTUH.
Quantity 6 - 250,000 BTUH heaters.
Building is 300 ft. long x 40 ft. wide.
Section
BTUH
LP Gas Pipe Size
Gas Load
@ 5 PSIG
A - B
1,500,000
1 in.
B - C
1,000,000
3/4 in.
C - D
750,000
3/4 in.
D - E
500,000
1/2 in.
E - F
250,000
1/2 in.
B - G
500,000
1/2 in.
G - H
250,000
1/2 in.
First Stage Pipe Sizing
5 PSIG Inlet with a 1 PSIG Pressure Drop
Maximum capacity of pipe or tubing, in thousands of BTU/hr. of LP Gas
IMPORTANT:
If exact length is not on chart, use next longer length. Select the size of pipe that shows at least as
much capacity as needed for each piping section.
Pipe Size
Length of Pipe or Tubing
(In Inches)
(In Feet)*
10
20
30
40
50
60
70
80
90
100
1/2
2946
2025
1626
1392
1233
1118
1028
957
897
848
3/4
6161
4234
3400
2910
2579
2337
2150
2000
1877
1773
1
11605
7976
6405
5482
4859
4402
4050
3768
3535
3339
125
150
175
200
225
250
275
300
350
400
1/2
751
681
626
583
547
516
490
468
430
400
3/4
1571
1424
1310
1218
1143
1080
1026
978
900
837
1
2956
2682
2467
2295
2153
2034
1932
1843
1696
1577
* Total length of piping from outlet of first stage regulator to inlet of second stage regulator (or to inlet of second
stage regulator furthest away).
August 1999
