Flange Size: 1" NPT 1¼" NPT 1½" NPT 1½" BSP 2" NPT 2-5/8" sq 2½" sq 2½" NPT 2½" w/plug sq 2½" x 2¾" rect 3" sq 3¼" rnd 4½" sq 5¾" sq 6" rnd 8½" rnd 9" rnd N/A N/A