Venting installation, Using elbow offsets (30e-12dm) – FMI MASONRY FIREBOX MM33 User Manual
Page 14
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125160-01A
14
Figure 16 - Ceiling Support Pipe 12S-12DM
asseMBlY and InsTallaTIon oF doUBle
Wall CHIMneY sYsTeM
Each double wall chimney section consists of a gal-
vanized outer pipe, a stainless steel inner flue pipe
and a wire spacer. The pipe sections must be as-
sembled independently as the chimney is installed.
When connecting chimney directly to the fireplace,
the inner flue pipe section must be installed first
with the lanced side up. The outer pipe section can
then be installed over the flue pipe section with the
hemmed end up. Press down on each pipe section
until the lances securely engage the hem on the fire-
place starter. The wire will assure the proper spacing
between the inner and outer pipe sections.
Continue to assemble chimney sections as outlined
above, making sure that both the inner and outer
pipe sections are locked together. When installing
double wall snap-lock chimney together, it is impor-
tant to assure the joint between the chimney sections
is locked. Check by pulling chimney upward after
locking. The chimney will not come apart if properly
locked. It is not necessary to add screws to keep the
chimney together (exception, see Figure 15).
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 15 - Elbow Offset
B
A
Screws
UsInG elBoW oFFseTs (30e-12dM)
1. To achieve desired offset, you may install combi-
nations of 12”, 18”, 24”, 36” and 48” length of double
wall pipe (see offset chart and Figure 15).
2. Chimney weight above offset rests on return elbow.
Straps must be securely nailed to rafters or joists (see
Figure 16, details A and B).
3. Maximum length of pipe between supports (return
elbow or 12S-12DM) is 6’ of angle run. Maximum of
two 6’ angle run sections per chimney system (see
Figure 17, page 16).
4. All pipe connections between the offset and re-
turn must be secured with two screws on the outer
pipe only (see Figure 15). Do not penetrate the in-
ner stainless.
2"
Min.
Straps
Detail A
Return Elbow
Detail B
Angle Firestop
See Detail A
See Detail B
Straps
Straps
Straps