[Stainless steel shall be welded using electrodes conforming to AWS A5.4.]
[Structural steel doors shall be of welded construction.] Fabricated steel
shall be well-formed to shape and size, with sharp lines and angles.
Intermediate and corner joints shall be coped or mitered. Exposed welds
shall be dressed smooth. [The stiles [and top] of built-up structural
steel doors shall be closed using channel shapes or plates.] [When
feasible, faceplates for structural steel doors shall be one piece. When
one-piece faceplates are not feasible, plates shall be joined using full
penetration groove weld butt joints or other approved welds.] [Reinforced
concrete doors shall be closed at the edges with structural steel channels
or plates and latch housings shall be mortised. Lap splices shall not be
used for flexural reinforcing bars.] [Spall plates shall be one piece,
covering the entire concrete surface on the seating face of the door, and
shall be securely welded to the door edges. Spall plates shall not be less
than 6 mm 1/4 inch thick.] [Faceplated reinforced concrete doors shall be
provided with one-piece faceplates on both door faces. Faceplates shall
cover the entire concrete surface and shall be securely welded at the door
edges. Faceplates shall be not less than 9 mm 3/8 inch thick.] [Hollow
metal door frames shall be pressed steel or structural steel with welded
joints. Steel frames or subframes installed in masonry walls shall be
provided with adjustable anchors. Hollow metal doors shall be of unitized
grid construction with welded grid junctions and shall have flat, one-piece
face sheets spot welded to each face of the grid system. The edges of
hollow metal doors shall be closed with seams continuously welded. Hollow
metal doors shall be neat in appearance, free from warpage and buckle, and
suitable reinforcing shall be provided for hardware.]
2.4.2
Mullion
Mullions for double doors shall be fabricated in the same manner specified
for frames. [Fixed mullions shall be welded to the frame.] [Removable
mullions shall be attached to the frame with mechanical fasteners that are
accessible for mullion removal or, in lieu of the removable mullion, an
astragal shall be provided at the seating face of the inactive door leaf.]
Doors shall seat directly against the mullion, and the mullion or astragal
shall be capable of transferring the door reactions to the frame.
2.4.3
Thermal Insulation
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NOTE: Thermal insulation is practical only for
hollow metal doors.
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The interior cells between the unitized grid shall be completely filled
with thermal insulation material. The U value through the door (panel)
shall not exceed [1.36] [_____] W per square meter per degree K [0.24]
[_____] Btu per square foot per hour per degree F.
2.4.4
Shop Finishing
[Shop priming of steel surfaces shall conform to Section 09900PAINTS AND
COATINGS, except that surfaces that will be embedded in concrete need not
be primed and hollow metal doors shall be either dipped in primer after
welding is completed, or exposed surfaces shall be primed and interior
surfaces coated with an approved rust inhibitor]. [Galvanizing of doors
and frames shall conform to ASTM A 123/A 123M or other approved methods.
Surfaces that will be embedded in concrete need not be galvanized and the
interior of hollow metal doors may be treated with an approved rust
SECTION 08390
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