Ultra Flow Trap / Strainer attached to A O Smith pump and motor (Century Centurian) 1.5 HP PN 7-177896-22 . Two Lid o-rings are listed on line depending on date of manufacture but I do not know date on assembly. Lid is an American Products PN 393016. Which O-ring fits that lid? Thanks—Paul
Part number 393016 was the lid for the older Ultra Flo model. The replacement lid o-ring is part number 5105-13.