E. Measuring Standards
Vertical and horizontal measurements listed in the vent
diagrams were made using the following standards:
• Pipe measurements are shown using the effective length
of pipe. See Section 12.A (Figure 12.1 for DVP, Figure
12.7 for SLP) for information on effective length of pipe
components.
• Horizontal terminations are measured to the outside
mounting surface (fl ange of termination cap) (see Figure
4.6).
• Vertical terminations are measured to top of last section
of pipe. See Figure 4.7.
• Horizontal pipe installed level with no rise.
Figure 4.6 Measure to Outside Mounting Surface
Figure 4.7. Measure to Top of Last Section of Pipe
Majestic • DBDV36IN, DBDV36IL, DBDV42IN, DBDV42IL Installation Manual • 2397-980 Rev. B • 5/16
MEASURE TO SHADED SURFACE
(OUTSIDE MOUNTING SURFACE)
F. Vent Diagrams
General Rules:
• SUBTRACT 3 ft. from the total H measurement for each
90º elbow installed horizontally.
• SUBTRACT 1-1/2 ft. from the total H measurement for
each 45º elbow installed horizontally.
• A maximum of three 90º elbows (or six 45º elbows) may
be used in any vent confi guration. Some elbows may be
installed horizontally. See Figure 4.11.
• Elbows may be placed back to back anywhere in the
system.
•
Any 90º elbow may be replaced with two back to back
45º elbows.
• When penetrating a combustible wall, a wall shield
fi restop must be installed.
• When penetrating a combustible ceiling, a ceiling fi restop
must be installed.
• Horizontal runs of vent do not require vertical rise;
horizontal runs may be level.
• Horizontal termination cap should have a 1/4 inch
downward slant to allow any moisture in cap to be
released. See Figure 4.8.
1/4 in. max.
(6 mm)
Figure 4.8
17