Valve Seat

Our high-chrome alloy designed for unleaded fuels which enables 40 hardness combined with easy machinability. Features excellent resistance to high temperature corrosion in applications to 1150�F. The Inspection and Quality maintenance program of Valve Seat Inserts O.D. Roundness The roundness of the outside diameter should be held to 0.013mm maximum O. D. to Bottom Face Perpendicularity This specification should be held to 0.002mm per mm of width. Seat Surface Gauge Height The gauge height tolerance for the seat surface is typically �0.04mm. Seat Surface Finish A finish specification of 0.8 Ra is typical of many manufacturers. Seat Surface Run-out to Bottom Face and O D Run-out of the seat to bottom face/O D is maintained to 0.04mm maximum. Seat Surface Angle The tolerance for seat surface angle is typically � 0.25�. Line Profile for Seat Surface Some manufacturers have a line profile (or roundness) specification for the seat surface. This specification is the most critical in ensuring a good seal between the valve and VSI. A typical specification for this feature is 0.02mm.