8″-30″ will be a 5 gore one piece standard throat construction. 32″ and larger in diameter 90 degree full sweep (1.5 x CL) elbows are fabricated using two 45 degree angles connected with an E-Z flange and barrel clamp unless otherwise specified.
Standing Seam Elbows & Angles with E-Z Flange for Spiral Pipe and Ductwork systems.