Injection molding valve

A ring valve for use with injection molding devices including a plurality of concentric members comprising:

• an axially translatable center valve body member adapted for translation between a first axial position and a second axial position, the center valve body member having a head portion of a first diameter and a shaft portion of a second, lesser diameter wherein the intersection of the head portion and the shaft portion defines a bearing surface;
• a replaceable front valve seat member defining a front valve seat disposed concentrically about the shaft portion of the center valve body member, the front valve seat member having a concentric center hub portion detachably coupled to the shaft and bearing surface of the center valve body member and having an annular outer front valve seat portion selectively sealing against a first end of a cylindrical outer check ring member;
• and
• a rear valve seat member defining a rear valve seat disposed concentrically about the axially translatable center valve body member, the rear valve seat member having a concentric center hub portion detachably coupled with the center valve body member shaft and the front valve seat member and having an annular outer rear valve seat portion selectively sealing against a second end of the cylindrical outer check ring member;
• the cylindrical outer check ring member being disposed concentrically about the shaft of the center valve body member for alternate sealing engagement with the front valve seat member and the rear valve seat member and being further disposed concentrically about the hub portion of the rear valve member;
• the ring valve, when the center valve body member is in the first axial position and the cylindrical outer ring is in sealing engagement with the front valve seat portion of the front valve seat member, providing substantially axial mass flow through a substantially annular opening and circumferentially about the head of the center valve member, the substantially annular opening defined between an annular first gap located between the outer check ring and the hub of the rear valve seat member and a substantially annular second gap located between the hub portion and the annular outer front valve seat portion of the front valve seat member.