Southwark Metal 21_30X12 Trunk Duct End Cap 30x12

Product Description

The SOUTHWARK METAL 21_30X12 is a rectangular sheet metal trunk duct end cap manufactured from hot-dipped galvanized steel. It is designed to close off the open end of a rectangular trunk duct in forced-air HVAC distribution systems. The 30-inch by 12-inch profile fits standard trunk duct sizes used in residential and light commercial ductwork. Sheet metal fabricators, HVAC installers, and mechanical contractors install this cap to terminate duct runs, prevent air bypass, and maintain system static pressure at the end of a supply or return trunk.

This end cap is used in rectangular trunk duct assemblies where a clean, sealed termination is required. Typical applications include supply air trunks run through attics, crawlspaces, and mechanical rooms in residential new construction and retrofit projects. The galvanized steel construction resists corrosion in environments with moderate humidity exposure. It is suited for low-pressure forced-air systems built to SMACNA and ACCA duct construction standards.

Key Features

• Hot-dipped galvanized steel construction provides corrosion resistance for long service life
• Rectangular profile matches standard 30-inch by 12-inch trunk duct dimensions
• Designed for trunk duct termination to eliminate air bypass at duct ends
• Fabricated to SMACNA and ACCA applicable standards for sheet metal ductwork
• Compatible with standard sheet metal duct assembly and fastening methods

Compatibility

Designed as an OEM-style sheet metal component for rectangular trunk duct systems built to SMACNA and ACCA ductwork standards at a 30-inch by 12-inch duct opening.

Installation Notes

Installation should be performed by a licensed HVAC technician or sheet metal contractor in accordance with SMACNA duct construction guidelines. Power down the air handling unit and confirm zero airflow before fitting the end cap to the duct opening. Secure the cap using drive cleats, S-cleats, or sheet metal screws per standard trade practice, and seal all joints with UL 181-rated mastic or foil tape to prevent air leakage. Wear appropriate cut-resistant gloves when handling sheet metal edges.

Technical Specifications

• Material: Hot Dipped Galvanized Steel
• Width: 12 inches
• Length: 30 inches
• Type: Rectangular Trunk End Cap
• Applicable Standards: ACCA, SMACNA

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: 21_30X12