Abstract: Apparatus and methods for indicating seal leakage between two components are provided. In one aspect, apparatus and methods for directing material penetrating a leaking nozzle repair shield seal to a predetermined indication point such that a user viewing such indication point is alerted to the leaking seal condition is provided. In one aspect of the present invention, a channel having six distinct sections directs the material to the indication point. These six channel sections include two annular sections extending about the periphery of a main cylindrical section and an inwardly facing surface of a flange of the nozzle repair shield. These six channel sections further include a reservoir and interconnecting channel sections. Also, a sleeve for encircling the outwardly facing surface of the main cylindrical section of the nozzle repair shield is provided and the indication point may be provided in the form of a reservoir.

Abstract: A valve seat and a valve assembly incorporating such valve seat form tight dual seals with glass lined nozzle of a reagent or reaction vessel. This reduces or eliminates cavities and crevices between the value seat and the nozzle where residues or contaminants can accumulate. Additionally, the present valve assembly comprises flush ports to permit the valve seat and the valve to be cleaned-in-place. This eliminates the need to disassemble the valve seat and/or the valve to remove the contaminants, thereby minimizing process “down time.