Product Description

The SOUTHWARK METAL mc-84l-d-8 is an 8-inch long-style duct board collar with an integrated damper, designed for use in forced-air distribution systems. This collar provides a transition point between the duct board and branch takeoffs or register boots, with the built-in damper allowing airflow to be adjusted or shut off at the zone level. It carries a dark bronze baked enamel finish that resists corrosion and blends with standard duct system aesthetics. HVAC installers and sheet metal contractors are the primary trades who work with this component during new construction or renovation duct system builds.

This collar is used in residential and light commercial forced-air HVAC applications where duct board is the primary trunk or branch material. The long-style design provides additional insertion depth into the duct board, improving the seal and structural connection at the penetration point. It is a common component in supply-side duct systems where zone damping at the collar level is preferred over downstream balancing dampers.

Key Features

Integrated damper allows airflow adjustment directly at the collar without a separate balancing component
Long-style design provides deeper insertion into duct board for a more secure and airtight fit
Dark bronze baked enamel finish for corrosion resistance and a clean appearance
8-inch nominal size fits standard 8-inch round duct board openings
Part of the 84STLWD series, consistent with Southwark Metal duct board accessory product line

Compatibility

Designed as an OEM-style replacement or new-installation fitting for duct board systems requiring an 8-inch collar with integral damper in long-style configuration.

Installation Notes

Installation is performed by licensed HVAC technicians or qualified sheet metal contractors. The forced-air system should be fully powered down and the air handler or furnace shut off before cutting into or modifying the duct board. Proper duct board knife technique and foil tape or mastic sealant should be used at the collar perimeter to maintain system airtightness per applicable mechanical codes. Do not overtighten or force the collar into undersized openings, as this can compromise the duct board face and reduce seal integrity.

Technical Specifications

Series: 84STLWD
Size: 8 inches
Style: Long
Finish: Dark Bronze Baked Enamel
Damper: Integrated

Standard Information

Brand: SOUTHWARK METAL
Manufacturer Part Number: mc-84l-d-8

Brand	SOUTHWARK METAL
MPN	MC-84L-D-8

Southwark Metal MC-84L-D-8 Duct Board Collar Damper 8in

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