Southwark Metal mc-84l-d-4 Duct Board Collar with Damper 4 in

Product Description

The SOUTHWARK METAL mc-84l-d-4 is a long style duct board collar with an integrated damper, sized for 4-inch round duct connections. It is designed to terminate ductboard supply trunks and transition to flexible or rigid branch runs in low-pressure residential and light commercial HVAC distribution systems. The long-style barrel provides additional insertion depth into ductboard, improving retention and reducing air bypass at the collar joint. Licensed HVAC installers and sheet metal mechanics typically install this fitting during new construction or duct replacement work.

This collar is suited for use in residential forced-air heating and cooling systems where ductboard is the primary trunk or plenum material. The built-in damper allows airflow balancing at the branch takeoff point without requiring a separate inline balancing damper. Typical installations include supply plenum penetrations, ductboard trunk-to-branch transitions, and air handler discharge assemblies where branch outlets need field-adjustable volume control.

Key Features

• Long-style barrel design provides deeper ductboard engagement for a secure, low-leakage fit
• Integrated damper enables airflow balancing directly at the collar without additional fittings
• 4-inch round connection size suits common residential branch duct runs
• Part of the 84STLWD series, a recognized ductboard fitting product line

Compatibility

Designed as an OEM-style replacement and new-construction fitting for residential and light commercial ductboard systems using 4-inch round branch connections.

Installation Notes

Installation should be performed by a qualified HVAC technician or licensed sheet metal mechanic. Shut down the air handling unit and confirm the system is de-energized before cutting ductboard or inserting the collar. Secure the collar with foil-backed tape and mastic sealant per SMACNA and local mechanical code requirements to minimize air leakage at the joint. Adjust the integral damper after system startup during the air balancing phase.

Technical Specifications

• Series: 84STLWD
• Style: Long Style
• Connection Size: 4 inches
• Damper: Integrated

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: mc-84l-d-4