Bray/Rite® wafer combination swing check valves are flow activated, and Rite Sized. Bray/Rite® inlet ports and disc have been shape optimized to achieve a fully open position at low flow rates (3 ft/s on average). Therefore, the Bray/Rite® operates exceptionally well in the flow rates typically found in pipelines containing control valves and lines with varying media flows.Compare the Bray/Rite® to typical full-sized swing check valves-- Due in part to their oversized, heavier discs, these valves only fully open at an average flow rate of 11 ft/s.