Venting installation, Continued, Using elbow offsets (30e-12dm) – FMI WCM-42G User Manual
Page 9
www.fmiproducts.com
122271-01D
9
VenTing inSTallaTion
Continued
OFFSET RISE
CHIMNEY LENGTH
A
B
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
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"
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 (22-50 FT. SYSTEM HEIGHT)
Figure 11 - Ceiling Support Pipe
12S-12DM
2" Min.
Straps
Straps
Straps
Straps
Detail A
Return Elbow
Detail B
Angle Firestop
See Detail A
See Detail B
Continue to assemble chimney sections as
outlined above, making sure that both the
inner and outer pipe sections are locked to-
gether. When installing double wall snap-lock
chimney together, it is important to assure
the joint between the chimney sections is
locked. Check by pulling chimney upward
after locking. The chimney will not come apart
Figure 10 - Elbow Offset
B
A
Screws
if properly locked. It is not necessary to add
screws to keep the chimney together (excep-
tion, see Figure 10).
USING ELBOW OFFSETS (30E-12DM)
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 10).
2. Chimney weight above offset rests on
return elbow. Straps must be securely
nailed to rafters or joists (see Figure 11,
details A and B).
3. Maximum length of pipe between sup-
ports (return elbow or 12S-12DM) is 6'
of angle run. Maximum of two 6' angle
run sections per chimney system (see
Figure 12, page 10).
4. All pipe connections between the offset
and return must be secured with two
screws on the outer pipe only (see
Figure 10). Do not penetrate the inner
stainless.