Venting Installation
Continued
Using ELBOW offsets
1.To achieve desired offset, you may install combinations of 12", 18", 24", 36" and 48" length of double wall pipe (see offset chart and Figure 7).
OFFSET RISE | CHIMNEY LENGTH |
AB 12" 18" 24" 36" 48"
4 3/8" 16 3/8" ELBOW SET ONLY
9 3/4" 25 1/2" 1
12 3/4" 30 3/4" |
| 1 |
|
| |
15" | 34 3/4" |
|
| 1 |
|
18" | 40" | 1 | 1 |
|
|
21 1/4" 46 1/4" |
|
| 1 |
| |
23 3/4" 49 1/4" |
| 1 | 1 |
| |
27 3/4" 56 3/4" |
|
|
| 1 | |
30" | 60 3/4" |
| 1 | 1 |
|
33" | 66" | 1 |
|
| 1 |
36" | 71" |
| 1 |
| 1 |
38 1/4" | 75" |
|
| 2 |
|
41 1/4" 80 1/4" | 1 | 1 | 1 |
| |
45" | 86 3/4" |
|
| 2 |
|
46 3/4" 89 1/2" | 1 | 1 |
| 1 | |
51" | 97" |
|
| 1 | 1 |
53 1/4" | 101" |
| 1 | 2 |
|
56 1/4" | 106 1/4" |
|
|
| 2 |
59 1/4" | 111 1/2" |
| 1 | 1 | 1 |
61 3/4" | 115 1/2" | 1 |
|
| 2 |
64 3/4" | 120 3/4" |
| 1 |
| 2 |
68 1/4" | 127" |
|
| 2 | 1 |
70" | 130" | 1 | 1 |
| 2 |
74 1/4" | 137 1/2" | 1 |
| 2 | 1 |
76 3/4" | 141 1/2" |
| 1 | 2 | 1 |
79 3/4" | 146 3/4" |
|
| 4 |
|
OFFSET CHART
2. Chimney weight above offset rests on return elbow. Straps must be securely nailed to rafters or joists (see Figure 8, details a and b).
3. Maximum length of pipe between supports (return elbow or
4. All pipe connections between the offset and return must be secured with two screws on the outer pipe only (see Figure 9, page 9). Do not penetrate the inner stainless.
2" Min.
Straps
Detail BStraps | See Detail B | |
Angle Firestop | ||
|
Straps
Straps
Detail A
Return Elbow
Figure 8 - Ceiling Support Pipe
| Return |
| Return |
|
| |
| Elbow |
| Elbow | Return |
| |
Offset |
|
|
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|
| |
| Offset |
|
| Elbow |
| |
Elbow | 6' Max. | Elbow | 6' Max. | Ceiling |
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| ||||
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Return |
|
|
| Support Pipe |
| |
| Return |
| 6' Max. | |||
Elbow |
|
| ||||
| Elbow |
|
|
|
| |
|
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|
| |
| 6' Max. | Offset | Offset |
|
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|
|
|
| ||
Offset |
| Elbow | 6' Max. Elbow |
| 6' Max. |
|
Elbow |
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|
|
|
|
|
| A |
| B |
| C |
|
Figure 7 - Typical Offset Terminations
8 | www.fmiproducts.com |