Southwark Metal ATT_18IN Duct Takeoff 18 Inch Air-tite

Product Description

The SOUTHWARK METAL ATT_18IN is an 18-inch diameter Air-Tite sheet metal duct takeoff fabricated from hot dip galvanized steel. Duct takeoffs connect branch ducts to a main trunk line, directing conditioned air through the distribution system. This fitting meets ACCA and SMACNA standards, confirming dimensional accuracy and construction quality appropriate for engineered duct systems. The galvanized steel construction resists corrosion in both supply and return applications. HVAC installers and sheet metal contractors use this fitting in new construction and retrofit projects where a reliable, airtight branch connection is required at the trunk.

This takeoff is suited for residential and light commercial forced-air systems where an 18-inch diameter branch tap is specified. It is used in low-pressure supply air distribution systems and is appropriate for applications where duct leakage control is a design priority. The Air-Tite designation indicates the fitting is designed to minimize air leakage at the connection point, supporting system efficiency and Manual D compliance in ducted HVAC installations.

Key Features

• 18-inch diameter opening for large-volume branch duct connections
• Hot dip galvanized steel construction for corrosion resistance in HVAC environments
• Air-Tite design reduces duct leakage at the takeoff connection
• Meets ACCA and SMACNA applicable standards for duct fittings
• Suitable for low-pressure forced-air supply distribution systems

Compatibility

Designed as an OEM-style replacement and new-installation fitting for 18-inch diameter branch connections in residential and light commercial sheet metal duct systems built to SMACNA and ACCA specifications.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified sheet metal contractor in accordance with SMACNA duct construction standards and local mechanical codes. Power down the air handler and close the system before cutting into the main trunk. Secure the takeoff with sheet metal screws and seal all joints with UL 181-listed mastic or foil tape to maintain system airtightness. Do not exceed the pressure class rating of the surrounding duct system.

Technical Specifications

• Diameter: 18 inches
• Material: Hot Dip Galvanized Steel
• Type: Air-Tite
• Applicable Standards: ACCA, SMACNA

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: ATT_18IN