L.B. White Pilot - Manual (Page 15)

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