ADBG-DR - Maximum Security Duct / Barrier Grille - High Tensile Strength

Contractor shall furnish and install the high tensile strength heavy-duty duct barrier grille, where shown on plans. Anemostat Products shall manufacture the units. The duct barrier grille shall be have an all steel welded perimeter 
construction, with interlocking high tensile strength steel bars. The vertical bars are double ribbed 7/8” diameter bars on 6” centers maximum. The horizontal bars are 2-1/2” x 3/8” flat bars punched to accept and interlock the vertical bars on 12” centers maximum. The sleeve is 10ga. steel with continuously welded seams. The interior of the sleeve encompasses a stitch welded interior frame which is 2-1/2” x 3/8” all around and is punched to accept the interlocking vertical bars. Two 1” x 1” x 3/16” locking angle frames shall be supplied, one continuously welded to the sleeve by the manufacture and one shipped loose for field weld to the sleeve. The ADBG-DR shall be primed with a red oxide or other similar rust-inhibiting coat. Optionally the bars may be heat treated to ASTM specifications for tool resisting steel (model ADBG-TR).