Which method is acceptable for joining duct seams?

Which method is acceptable for joining duct seams?

• A. Liquid-tight, continuously external welds
• B. Screwed joints with sealant
• C. Duct tape and screws
• D. Riveted joints

Answer: (A)

Joining duct seams with liquid-tight, continuously external welds provides a single, uninterrupted seal along the seam, preventing grease and air from leaking out and helping the system meet safety and performance standards. This method creates a durable barrier that withstands the heat and humidity found in kitchen exhaust, while keeping the interior surface smooth for efficient airflow. Other methods like screws with sealant, duct tape, or riveted joints often fail to provide a reliable, airtight seal under these conditions, leading to leaks, buildup, and potential hazards.

Joining duct seams with liquid-tight, continuously external welds provides a single, uninterrupted seal along the seam, preventing grease and air from leaking out and helping the system meet safety and performance standards. This method creates a durable barrier that withstands the heat and humidity found in kitchen exhaust, while keeping the interior surface smooth for efficient airflow. Other methods like screws with sealant, duct tape, or riveted joints often fail to provide a reliable, airtight seal under these conditions, leading to leaks, buildup, and potential hazards.