What method is used to attach a round branch to a spiral pipe?

The correct method to attach a round branch to a spiral pipe is the dovetail method. This technique is particularly effective in creating a secure and tight connection between pipes. The dovetail connection involves shaping the end of the branch pipe to fit snugly into a matching groove or channel on the main spiral pipe, ensuring that there is minimal leakage and enhanced structural integrity.

Using a dovetail joint is beneficial in the HVAC industry because it allows for a strong mechanical bond that can withstand the pressures within a duct system. This method also aids in maintaining the aesthetic appearance of the installation, as the connection can be made without the need for additional fittings or external flanges.

Other methods, such as spinning in collar or S and D, are alternatives for connecting pipes but may not provide the same level of ease in fabrication or airtightness that the dovetail method offers. Understanding the right attachment techniques is essential for HVAC technicians to ensure the efficiency and reliability of the air distribution system.