Greenheck Support Mullions for use in Oversize Openings (462105) - Manual

These installation instructions apply to the fabrication and construction of generic support mullions. Support mullions
are necessary whenever static fire dampers are installed into a vertical opening that is larger than the largest UL rated
size for that damper. The mullions allow construction of a fire barrier that is larger than the maximum available size.
The opening must not exceed 120 in. (3048mm) high, but can be any width provided a vertical support mullion is used a
maximum of every 120 inches (3048mm).
To properly use support mullions they must be fabricated and installed according to the following instructions.
E
E
F
F
D
D
G
G
G
G
Wall Mullion Cap
B-B (Typical)
Mullion Assembly
A-A (Typical)
Retaining Angles (Typical)
Sleeve (Typical)
Horz. to Vert.
Mullion Cap
C-C (Typical)
Document number 462105
FABRICATION AND FIELD
INSTALLATION INSTRUCTIONS
Support Mullions for use in Oversize Openings
SPECIAL NOTE: Support
mullions may only be used
with static-rated fire damper
assemblies; they cannot be used
to install combination fire-smoke
dampers in wall openings that
exceed the maximum UL-approved
size for the fire-smoke damper
model being installed.
Application
Generic steel mullions can be used to separate vertically
mounted galvanized steel fire dampers in wall openings
larger than the UL permitted multiple damper assembly
size. Mullions can either be used vertically, horizontally or
both to split up a vertical wall opening requiring use of a
damper having a 1
1 /
2
hour fire resistance rating. Maximum
mullion span is 120 in. (3048mm) plus expansion allowance
when used either horizontally or vertically.
Sleeves are to be around each damper assembly. Mullions
are not intended to be in the airstream, (i.e. exposed to
flow) or to be a part of the ductwork.
Wall Opening
Steel mullions are intended for use in a concrete block or
solid concrete wall.
Hollow concrete blocks are to be filled with concrete
(minimum 3500 psi) to permit proper mullion anchoring.
Wall thickness is to be 7 in. (178mm) minimum, 12 in.
(305mm) maximum.
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