Abstract: A bypass valve assembly for use in turbine generators includes a valve body defining a central bore and a plurality of passageways. Each passageway has a smaller area at an inlet portion and a larger area at an outlet portion to define a flared passageway. A plurality of bypass valves is disposed within the plurality of passageways within the valve body. Each bypass valve includes a base portion and a nose portion, with each nose portion defining a predefined contoured surface area. At least a portion of the contoured surface area includes a wear coating disposed thereon. Optionally, the wear coating includes a plasma enhanced magnetron sputtering nanocoating.