Southwark Metal PH74148 Duct Boot 4x14x8 in 30 Gauge

Product Description

The SOUTHWARK METAL PH74148 is a straight, rectangular-to-round sheet metal duct boot designed for connecting rectangular duct runs to round collar openings at register locations in forced-air HVAC systems. The body is fabricated from 30-gauge ASTM A653 CS Type B G40 hot-dip galvanized steel, with a heavier 28-gauge collar for added rigidity at the connection point. The flat-back design seats flush against framing or subfloor assemblies, making it well-suited for floor and wall register installations. Licensed HVAC technicians and sheet metal contractors install this fitting as part of residential and light commercial duct distribution systems.

This boot transitions a 4-inch by 14-inch rectangular opening on the A-side to an 8-inch round collar on the B-side. The straight configuration is typical for floor-mount register applications where the duct rises vertically from a horizontal trunk or branch run. The hot-dip galvanized finish provides corrosion resistance appropriate for unconditioned spaces such as crawlspaces, basements, and attic framing bays. Fabrication conforms to ACCA, SMACNA, and NATE applicable standards, making it compatible with properly engineered residential duct systems.

Key Features

• 30-gauge galvanized steel body with 28-gauge collar for reinforced connection point
• ASTM A653 CS Type B G40 hot-dip galvanized steel for corrosion resistance
• Straight, rectangular-to-round geometry transitions 4 x 14 inch duct to 8-inch round collar
• Flat-back construction for flush seating against framing members
• Fabricated to ACCA, SMACNA, and NATE applicable standards

Compatibility

Designed as an OEM-style sheet metal fitting for residential and light commercial forced-air duct systems requiring a straight rectangular-to-round register boot transition at a 4 x 14 inch by 8-inch collar size.

Installation Notes

Installation should be performed by a licensed HVAC technician or sheet metal contractor in accordance with SMACNA duct construction standards and local mechanical codes. Power down the air handling unit and shut off any associated heating or cooling equipment before cutting into existing ductwork. Seal all joints with UL 181-rated mastic or approved metal duct tape to maintain system pressure integrity. Secure the collar connection to the branch duct with sheet metal screws spaced per SMACNA guidelines.

Technical Specifications

• Size A (Rectangular Opening): 4 inches x 14 inches
• Size B (Round Collar): 8 inches
• Body Material Thickness: 30 gauge
• Collar Material Thickness: 28 gauge
• Material: ASTM A653 CS Type B G40 Hot-Dip Galvanized Steel
• Type: Straight, Rectangular to Round, Register
• Back Style: Flat Back
• Applicable Standards: ACCA, SMACNA, NATE

Standard Information

• Brand: SOUTHWARK METAL
• Manufacturer Part Number: PH74148