Burnham Apex APX399 Installation, Operating And Service Instructions page 60

Vii. gas Piping
B.
Connect boiler gas valve to gas supply system.
Warning
Failure to use proper thread compounds on all
gas connectors may result in leaks of flammable
gas.
Table 19B: Maximum Capacity of Schedule 40 Black Pipe in CFH* (LP gas) For gas Pressures
of 0.5 psig or Less
nominal inside
Pipe Size, in. Diameter, in.
½ 0.622
¾ 0.824
1 1.049
1¼ 1.380
1½ 1.610
2 2.067
2½ 2.469
3 3.068
nominal inside
Pipe Size, in. Diameter, in.
½ 0.622
¾ 0.824
1 1.049
1¼ 1.380
1½ 1.610
2 2.067
2½ 2.469
3 3.068
* 1 CFH of LP Gas is approximately equal to 2.5 MBH; contact your gas supplier for the actual heating value of your gas.
Table 20: Equivalent Lengths of Standard Pipe Fittings & Valves
nominal inside
Pipe Size, Diameter,
inc. in.
½ 0.622
¾ 0.824
1 1.049
1¼ 1.38
1½ 1.61
2 2.067
2½ 2.469
3 3.068
60
(continued)
inlet Pressure 11.0 inch W.C.; 0.3 inch W.C. Pressure Drop
10 20
88 60
184 126
346 238
710 488
1064 732
2050 1409
3267 2246
5776 3970
inlet Pressure 11.0 inch W.C.; 0.5 inch W.C. Pressure Drop
10 20
116 80
242 166
456 314
937 644
1403 964
2703 1858
4308 2961
7615 5234
Valves (Screwed) - Fully Open
gate globe angle
0.4 17.3 8.7
0.5 22.9 11.4
0.6 29.1 14.6
0.8 38.3 19.1
0.9 44.7 22.4
1.2 57.4 28.7
1.4 68.5 34.3
1.8 85.2 42.6
gas supply to boiler and system must be
absolutely shut off prior to installing or servicing
boiler gas piping.
Length of Pipe, Ft.
30 40 50
48 41 37
101 87 77
191 163 145
392 336 297
588 503 446
1131 968 858
1803 1543 1368
3188 2729 2418
Length of Pipe, Ft.
30 40 50
64 55 48
134 114 101
252 215 191
517 442 392
775 663 588
1492 1277 1131
2377 2035 1803
4203 3597 3188
Swing 45° 90°
Check Elbow Elbow
4.3 0.7 1.6
5.7 1.0 2.1
7.3 1.2 2.6
9.6 1.6 3.5
11.2 1.9 4.0
14.4 2.4 5.2
17.1 2.9 6.2
21.3 3.6 7.7
Warning
60 70 80
33 31 29
70 64 60
131 121 112
269 248 231
404 371 346
778 715 666
1239 1140 1061
2191 2016 1875
60 70 80
44 40 38
92 85 79
173 159 148
355 327 304
532 490 456
1025 943 877
1634 1503 1399
2889 2658 2472
Screwed Fittings
180 Close 90 Tee
return Flow Thru
Bend run
3.5 1.6
4.6 2.1
5.8 2.6
7.7 3.5
9.0 4.0
11.5 5.2
13.7 6.2
17.1 7.7
90 100
27 25
56 53
105 100
216 204
324 306
624 590
995 940
1760 1662
90 100
35 33
74 70
139 131
285 269
427 404
823 778
1312 1239
2320 2191
90 Tee, Flow
Thru Branch
3.1
4.1
5.2
6.9
8.0
10.3
12.3
15.3