The maximum flow rating for this suction fitting is 120 GPM. This suction fitting is designed for installation in conjunction with at least one other suction fitting per pump. A minimum size of 3” SCH 40 PVC pipe is to be used. Field built sumps  should be constructed per ANSI/APSP-16 Figure 2 (see below) found on page 5 of the Standard. Suction fitting and fasteners should be observed for damage or tampering before each use. Missing, broken, or cracked suction fittings shall be replaced before use. Loose suction fittings shall be reattached or replaced before use. Contact your local pool and spa professional for all winterizing instructions and recommendations. Open area is 38.90 in2.