Southwark Metal 20_18X8 Trunk Duct Collar 18x8 Straight

Product Description

The SOUTHWARK METAL 20_18X8 is a straight-pattern starting collar designed for sheet metal trunk duct systems in forced-air HVAC installations. Fabricated from hot dip galvanized steel, this trunk duct collar provides a rigid, corrosion-resistant connection point where a branch or main trunk run begins off a plenum or larger duct section. It measures 18 inches by 8 inches and is built to dimensional standards recognized by SMACNA and ACCA. Sheet metal workers and HVAC installers use this collar during new construction and retrofit duct fabrication to establish clean, leak-resistant trunk connections.

This starting collar is suited for residential and light commercial forced-air duct systems where trunk lines originate from a supply plenum or air handler. The straight body pattern makes it a direct-fit starting point for rectangular trunk runs. It is appropriate for low-pressure supply or return duct applications where galvanized steel construction is required by design specifications or local mechanical codes.

Key Features

• Hot dip galvanized steel construction for corrosion resistance in HVAC duct environments
• Straight body pattern for direct trunk run starting applications
• 18 x 8 inch opening matches standard rectangular duct dimensions
• Meets SMACNA and ACCA applicable standards for sheet metal ductwork
• Starting collar design simplifies trunk duct layout at the plenum connection point

Compatibility

Designed as an OEM-style sheet metal component for use in standard rectangular trunk duct systems fabricated to SMACNA and ACCA dimensional guidelines.

Installation Notes

Installation is performed by licensed sheet metal workers or HVAC technicians. Shut down the air handling system and de-energize the unit before beginning any duct connection work. Secure the collar to the plenum or duct section using sheet metal screws and seal all joints with UL 181-rated mastic or foil tape in accordance with local mechanical code requirements. Refer to SMACNA duct construction standards for reinforcement and support specifications.

Technical Specifications

• Size: 18 inches x 8 inches
• Material: Hot Dip Galvanized Steel
• Body Pattern: Straight
• Type: Starting
• Applicable Standards: ACCA, SMACNA

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: 20_18X8