The E-Z flange with barrel clamp can be factory installed or
shipped loose for field installation. A set consists of two E-Z
flanges and one barrel clamp. For field installation the
installer attaches the E-Z flange to the pipe and fittings.
Next the installer applies the gasket to one flange, mates
the two flanges together and attaches the barrel clamp.
Sheet Metal Connectors can also install E-Z flanges.
Flanges are spot welded and internally sealed on all ends of
the spiral pipe and fittings
Isn't this called a Vanstone flange?
diehardmercfan 7 hours ago