Abstract: The nose seal assembly is utilized in a centrifugal chemical analysis apparatus wherein compressed air and wash water tubings are coupled through the assembly to the nose of an open ended hollow shaft for providing a seal between the nose and the assembly upon relative rotational movement therebetween. The assembly comprises a hollow bushing to which is clamped an annular web pad which is made of Nylatron NSB .RTM. having a high pressure x velocity (PV) factor and a low coefficient of friction. The assembly further includes a heat dissipation disc to which the wear pad is clamped and an elastomeric washer which is cemented to and between the bushing and the heat dissipation disc and which is designed to provide sufficient "give" to enable the assembly to maintain a good seal when the wear surface of the wear pad is not coplanar with the plane of the nose. Also, the nose has a hemi-toroid configuration to enhance sealing with, and to reduce wear of, the wear pad.