A plug-type, rising stem needle or shut-off valve for controlling fluid flow comprises a valve housing forming a valve chamber with inlet and outlet ports connecting therewith.Balance Valves A bonnet member with a cylindrical passage joins with the valve chamber and opens to the exterior of the valve. A plug valve element is mounted in the chamber and adapted to be moved by an operating stem axially movable within the cylindrical passage. Needle ValvesThe stem includes a radially extending guide flange. For sealing about the operating stem and limiting the axial outwardly movement of the stem there is an assembly which includes a wall surface that defines a conical chamber at the outer end of the cylindrical passage. The conical chamber tapers from a large diameter at the axial outer end to a smaller diameter at the axial inner end. At the axial inner end of the conical chamber is a cylindrical counterbore carrying a stop ring which forms a radial shoulder for engaging the flange on the stem at a predetermined outer limit position. BUTTERFLY VALVES The stop ring has an axial outer end surface that defines a continuation of the conical chamber. A sealing ferrule is positioned in the conical chamber. The ferrule has a continuous radial outer surface which sealingly engages both the wall surface which defines the conical chamber and the axial outer end surface of the stop ring.

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