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15
Combustion-air and vent piping
MAXIMUM ALLOWABLE PIPE LENGTH (FT)
See notes on pg. 16.
ALTITUDE
ABOVE SEA
LEVEL (FT)
UNIT SIZE
TERMINATION TYPE
PIPE DIA
(IN.)
*
NUMBER OF 90° ELBOWS
1
2
3
4
5
6
0 to 2000
040-14
2 Pipe or 2-In. Concentric
1-1/2
50
45
40
35
30
25
2
70
70
70
70
70
70
060-14
2 Pipe or 2-In. Concentric
1-1/2
50
45
40
35
30
25
2
70
70
70
70
70
70
080-14
080-20
2 Pipe or 2-In. Concentric
1-1/2
30
25
20
15
10
5
2
70
70
70
70
70
70
100-20
2 Pipe or 2-In. Concentric
2
45
40
35
30
25
20
2-1/2
70
70
70
70
70
70
120-20
2 Pipe or 3-In. Concentric
2-1/2
10
NA
NA
NA
NA
NA
3
35
30
15
NA
NA
NA
3†
70
70
70
70
70
70
2001 to 3000
040-14
2 Pipe or 2-In. Concentric
1-1/2
45
40
35
30
25
20
2
70
70
70
70
70
70
060-14
2 Pipe or 2-In. Concentric
1-1/2
45
40
35
30
25
20
2
70
70
70
70
70
70
080-14
080-20
2 Pipe or 2-In. Concentric
1-1/2
26
21
16
11
6
NA
2
70
70
70
70
70
70
100-20
2 Pipe or 2-In. Concentric
2
40
35
30
25
20
15
2-1/2
70
70
70
70
70
70
120-20
2 Pipe or 3-In Concentric
3
31
26
12
NA
NA
NA
3†
63
62
62
61
61
61
3001 to 4000
040-14
2 Pipe or 2-In. Concentric
1-1/2
42
37
32
27
22
17
2
70
70
70
70
70
70
060-14
2 Pipe or 2-In. Concentric
1-1/2
42
37
32
27
22
17
2
70
70
70
70
70
70
080-14
080-20
2 Pipe or 2-In. Concentric
1-1/2
25
20
15
10
5
NA
2
70
70
70
70
70
70
100-20
2 Pipe or 2-In. Concentric
2
38
33
28
23
18
13
2-1/2
70
70
70
70
70
70
120-20
2 Pipe or 3-In. Concentric
3
29
24
10
NA
NA
NA
3†
59
59
58
57
57
56
4001 to 5000‡
040-14
2 Pipe or 2-In. Concentric
1-1/2
40
35
30
25
20
15
2
70
70
70
70
70
70
060-14
2 Pipe or 2-In. Concentric
1-1/2
40
35
30
25
20
15
2
70
70
70
70
70
70
080-14
080-20
2 Pipe or 2-In. Concentric
1-1/2
23
18
13
8
NA
NA
2
70
70
70
70
70
68
100-20
2 Pipe or 2-In. Concentric
2
36
31
26
21
16
11
2-1/2
70
70
70
70
70
70
120-20
2 Pipe or 3-In. Concentric
3†
56
55
54
53
52
52
5001 to 6000‡
040-14
2 Pipe or 2-In. Concentric
1-1/2
37
32
27
22
17
12
2
70
70
70
70
70
70
060-14
2 Pipe or 2-In. Concentric
1-1/2
37
32
27
22
17
12
2
70
70
70
70
70
70
080-14
080-20
2 Pipe or 2-In. Concentric
1-1/2
22
17
12
7
NA
NA
2
70
70
70
70
68
63
100-20
2 Pipe or 2-In. Concentric
2
33
28
23
18
13
8
2-1/2
70
70
70
70
70
70
120-20
2 Pipe or 3-In. Concentric
3†
53
52
50
49
48
47