Diameter
Ø (in.)
3°
15°
30°
45°
90°
5
1/2
2 1/2
5 1/4
8 1/4
18 1/2
6
1/2
2 1/2
5 3/8
8 1/2
19 1/2
7
1/2
2 5/8
5 1/2
8 3/4
20 1/2
8
1/2
2 5/8
5 3/4
9 1/8
21 1/2
9
1/2
2 5/8
5 7/8
9 3/8
22 1/2
10
1/2
2 5/8
6
9 5/8
23 1/2
11
1/2
2 3/4
6 1/8
10
24 1/2
12
1/2
2 3/4
6 1/4
10 1/4
25 1/2
13
1/2
2 3/4
6 3/8
10 1/2
26 1/2
14
1/2
2 3/4
6 1/2
10 7/8
27 1/2
16
1/2
2 7/8
6 3/4
11 3/8
29 1/2
18
1/2
3
7
12
31 1/2
20
1/2
3
7 1/4
12 5/8
33 1/2
22
1/2
3 1/8
7 5/8
13 1/8
35 1/2
24
1/2
3 1/8
7 7/8
13 3/4
37 1/2
26
1/2
3 1/4
8 1/8
14 3/8
39 1/2
28
1/2
3 1/4
8 3/8
14 7/8
41 1/2
30
1/2
3 3/8
8 5/8
15 1/2
43 1/2
32
1/2
3 3/8
8 7/8
16 1/8
45 1/2
34
1/2
3 1/2
9 1/8
16 3/4
47 1/2
36
1/2
3 1/2
9 1/2
17 1/4
49 1/2
Dimensions are in inches
TABLE 8b - Minimum (2) Elbow Offsets - DAS1 & DIS1
Diameter
Ø (in.)
3°
15°
30°
45°
90°
5
1/2
2 3/4
6 1/8
10
24 1/2
6
1/2
2 3/4
6 1/4
10 1/4
25 1/2
7
1/2
2 3/4
6 3/8
10 1/2
26 1/2
8
1/2
2 3/4
6 1/2
10 7/8
27 1/2
9
1/2
2 7/8
6 5/8
11 1/8
28 1/2
10
1/2
2 7/8
6 3/4
11 3/8
29 1/2
11
1/2
2 7/8
6 7/8
11 3/4
30 1/2
12
1/2
3
7
12
31 1/2
13
1/2
3
7 1/8
12 1/4
32 1/2
14
1/2
3
7 1/4
12 5/8
33 1/2
16
1/2
3 1/8
7 5/8
13 1/8
35 1/2
18
1/2
3 1/8
7 7/8
13 3/4
37 1/2
20
1/2
3 1/4
8 1/8
14 3/8
39 1/2
22
1/2
3 1/4
8 3/8
14 7/8
41 1/2
24
1/2
3 3/8
8 5/8
15 1/2
43 1/2
26
1/2
3 3/8
8 7/8
16 1/8
45 1/2
28
1/2
3 1/2
9 1/8
16 3/4
47 1/2
30
1/2
3 1/2
9 1/2
17 1/4
49 1/2
32
1/2
3 5/8
9 3/4
17 7/8
51 1/2
34
1/2
3 3/4
10
18 1/2
53 1/2
36
1/2
3 3/4
10 1/4
19
55 1/2
TABLE 8d - Minimum (2) Elbow Offsets - DIS4
Dimensions are in inches
Diameter
Ø (in.)
3°
15°
30°
45°
90°
5
1/2
2 5/8
5 1/2
8 3/4
20 1/2
6
1/2
2 5/8
5 3/4
9 1/8
21 1/2
7
1/2
2 5/8
5 7/8
9 3/8
22 1/2
8
1/2
2 5/8
6
9 5/8
23 1/2
9
1/2
2 3/4
6 1/8
10
24 1/2
10
1/2
2 3/4
6 1/4
10 1/4
25 1/2
11
1/2
2 3/4
6 3/8
10 1/2
26 1/2
12
1/2
2 3/4
6 1/2
10 7/8
27 1/2
13
1/2
2 7/8
6 5/8
11 1/8
28 1/2
14
1/2
2 7/8
6 3/4
11 3/8
29 1/2
16
1/2
3
7
12
31 1/2
18
1/2
3
7 1/4
12 5/8
33 1/2
20
1/2
3 1/8
7 5/8
13 1/8
35 1/2
22
1/2
3 1/8
7 7/8
13 3/4
37 1/2
24
1/2
3 1/4
8 1/8
14 3/8
39 1/2
26
1/2
3 1/4
8 3/8
14 7/8
41 1/2
28
1/2
3 3/8
8 5/8
15 1/2
43 1/2
30
1/2
3 3/8
8 7/8
16 1/8
45 1/2
32
1/2
3 1/2
9 1/8
16 3/4
47 1/2
34
1/2
3 1/2
9 1/2
17 1/4
49 1/2
36
1/2
3 5/8
9 3/4
17 7/8
51 1/2
TABLE 8c -Minimum (2) Elbow Offsets - DIS2
Dimensions are in inches
19
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
INCREASERS AND REDUCERS
Frequently, a diameter change is required in a chimney installation. To accomplish such
a size change, a step increaser or tapered increaser may be used. These parts are
usually used to provide an increase of size, as the name implies. However, the Tapered
Increaser can be turned to Tapered Reducer to reduce the size of a run. Extreme caution
should be exercised when reducing the size of a chimney. The resultant pressure
drop may cause the chimney to mis-function and cause spillage of flue gases into the
mechanical room.
The step increaser should be used when the length of run available for the size change
is restricted. The step increaser is a non-structural part and must not be subjected to
loading in either the axial or lateral direction.
TAPERED INCREASER (TINØ) and
TAPERED REDUCER
(RDØ)
The Tapered Increaser Adapter is used for a diameter change in duct system. Uses when
there is a sufficient length for duct run available for the size change. The
TINØ
uses 2” of
length per 1” increment diameter change. The
TINØ
is considered to have the same load
strength as a straight duct. See
Figure 37
.
Removable
Alignment
Sleeve
Figure 37 - Tapered Increaser
Adapter (TINØ)
Figure 38 - ECCENTRIC TAPERED
INCREASER (ETINØ)
ECCENTRIC TAPERED INCREASER (ETINØ)
The Eccentric Tapered Increaser Adapter is similar as the Tapered Increaser Adapter
except the smaller diameter is offset from the larger diameter. When installed horizontally,
the
ETINØ
keep a flat slope unlike the
TINØ
. See
Figure 38.
STEP INCREASER (INØ)
The Step Increaser
(INØ)
should be used when the length of run available for the size
change is restricted. The step increaser is a non-structural part and must not be subjected
to loading in either the axial or lateral direction. See
Figure 39.
Figure 39 - STEP INCREASER (INØ)
