L.B. White Pilot Light Ignition Installation And Service Manual page 15

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.
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
(In Inches)
10
1/2 2946
3/4 6161
1 11605
125
1/2 751
3/4 1571
1 2956
* 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
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
A - B
B - C
C - D
D - E
E - F
B - G
G - H
20 30 40
2025 1626 1392
4234 3400 2910
7976 6405 5482
150 175 200
681 626 583
1424 1310 1218
2682 2467 2295
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
BTUH LP Gas Pipe Size
Gas Load
1,500,000
1,000,000
750,000
500,000
250,000
500,000
250,000
Length of Pipe or Tubing
(In Feet)*
50 60
1233 1118
2579 2337
4859 4402
225 250
547 516
1143 1080
2153 2034
Installation
Instructions
Pipe Sizing
@ 5 PSIG
1 in.
3/4 in.
3/4 in.
1/2 in.
1/2 in.
1/2 in.
1/2 in.
70 80 90
1028 957 897
2150 2000 1877
4050 3768 3535
275 300 350
490 468 430
1026 978 900
1932 1843 1696
100
848
1773
3339
400
400
837
1577
2.2-2 2