Air Flow Products 77F182318 Transition Boot 18x23-18

Product Description

The AIR FLOW PRODUCTS 77F182318 is a straight transition boot with flange designed to connect square or rectangular ductwork to a round collar in forced-air HVAC systems. The boot transitions from an 18 by 23 inch rectangular opening down to an 18 inch round collar, making it a critical fitting wherever duct geometry changes between trunk lines and branch runs. The flanged design provides a secure, stable mounting surface against ceilings, floors, or framing. Licensed HVAC technicians and sheet metal contractors install this fitting during new construction and duct retrofit work.

This transition boot is suited for residential and light commercial forced-air applications where a square-to-round conversion is needed at a register, grille, or inline duct junction. It is commonly installed at the plenum-to-trunk or trunk-to-branch transition point and is appropriate for supply or return duct configurations depending on system layout and static pressure requirements.

Key Features

• Straight-body design keeps airflow transition gradual and consistent
• Integrated flange provides a solid mounting surface for register or grille attachment
• Square-to-round geometry accommodates rectangular trunk to round branch transitions
• 18 by 23 inch rectangular inlet matches common trunk duct sizing
• 18 inch round collar outlet connects directly to standard round duct or flex duct

Compatibility

Designed as an OEM-style sheet metal fitting compatible with standard forced-air duct systems using 18 by 23 inch rectangular openings and 18 inch round collars.

Installation Notes

Installation should be performed by a licensed HVAC technician or qualified sheet metal contractor in accordance with SMACNA ductwork standards and applicable local mechanical codes. Power down the air handler and confirm the system is depressurized before making connections at the plenum or trunk line. Seal all joints with listed duct sealant or foil-backed tape rated for HVAC use. Support the fitting per local code requirements to prevent strain on adjoining ductwork.

Technical Specifications

• Inlet Size: 18 x 23 inches rectangular
• Collar Diameter: 18 inches round
• Boot Style: Straight with Flange
• Transition Type: Square to Round

Standard Information

• Brand: AIR FLOW PRODUCTS
• Manufacturer Part Number: 77F182318