Two position rotary valve for injecting sample liquids into an analysis system

For use with a source of liquid from which liquid flows at a first pressure to a liquid receiver a rotary valve, positionable in either a first position, definable as a load position, or a second position, definable as an inject position, for injecting a liquid sample into the stream of liquid from said source to said receiver, the valve comprising:

• a stationary stator including a plurality of external ports and a corresponding plurality of internal liquid flow paths in communication with said ports, said ports including a pair of ports connectable to said source and receiver, and further including a group of n ports, where n is an integer not less than 4;
• an external conduit defining a sample loop through which liquid is adapted to flow, said sample loop being of a selected length and internal diameter and being connected to first and second of said n ports, said n ports including at least third and fourth ports exposed to a second pressure, less than said first pressure;
• and
• rotor means rotatable with respect to said rotor about a selected axis to thereby position said valve in either said load or inject position, and including a cavity having first and second open ends, said rotor means further including first, second and third rotor flow passages, said first rotor passage providing a liquid flow path between the stator internal flow paths in communication with said first external port and the first end of said cavity only when said valve is in said load position, and providing a flow path between the first end of said cavity and said fourth port when the valve is in said inject position, said second rotor passage providing a flow path when said valve is in said load position between the internal flow paths in communication with said second and third ports, and further providing a flow path between the internal paths in communication with said second port and one of said pair of ports when the valve is in said inject position, said third rotor passage providing a flow path between the internal flow paths which are in communication with said pair of ports when the valve is in the load position, and further providing a flow path between the internal flow paths in communication with said first port and the other of said pair of ports when said valve is in said inject position, said cavity, being accessible from the valve exterior through the second open end thereof for facilitating the injection of a sample into said sample loop through said first rotor passage when said valve is in said load position.

For use in combination with a source of liquid from which liquid flows at a selected pressure greater than atmospheric pressure to a liquid receiver a rotary valve, positionable in either a first position, definable as a load position, or a second position, definable as an inject position, for injecting a liquid sample into the liquid stream from said source to said receiver, the valve comprising:

• a stator including a plurality of external ports and a corresponding plurality of internal liquid flow paths in communication with said ports, said ports including first and second ports connectable to said receiver and source, respectively, a third port vented to atmospheric pressure, and a fourth port;
• an external conduit defining a fixed length sample loop having a first end connected to said fourth port and a second opposite end;
• rotatable rotor means defining a needle cavity connected to the sample loop second end, and defining a first end and an opposite second end, said rotor means further defining first and second rotor flow passages, said first rotor passage providing a flow path between the cavity first end to the stator internal path in communication with said second port only when said valve is in said inject position, and said second rotor passage providing a flow path between the stator internal paths in communication with said third and fourth ports when said valve is in said load position, and between the stator internal paths in communication with said first and fourth ports when said valve is in said inject position, said rotor means further including seal means for sealing the cavity first end, said seal means defining an opening accessible from the valve exterior for facilitating the insertion of a syringe needle into said cavity therethrough for injecting a liquid sample into said sample loop through said cavity;
• plug means for effectively closing the opening of said seal means, said seal means with said plug means being adapted to withstand said selected pressure when liquid flows through said cavity at said selected pressure when said valve is in said inject position, said rotor means being rotatable about a selected axis, with said needle cavity being an elongated cavity axially aligned with said selected axis.

For use with a source of liquid from which liquid flows at a first pressure to a liquid receiver a rotary valve positionable in either a first position definable as a load position or a second position definable as an inject position, for injecting a liquid sample into the stream of liquid from said source to said receiver, the valve comprising:

• a stationary stator including a plurality of external ports and a corresponding plurality of internal liquid flow paths in communication with said ports, said ports including a pair of ports connectable to said source and receiver, and further including at least additional first, second and third ports;
• an external conduit defining a sample loop through which liquid is adapted to flow, said conduit being of a selected length and internal diameter and being connected to said first and second ports, said third port being exposed to a second pressure less than said first pressure;
• rotor means rotatable with respect to said stator about a selected axis to thereby position said valve in either said load or inject position, and including a cavity having first and second open ends, said first open end being in flow communication with said first external port irrespective of the valve position, said rotor means further including first and second rotor flow passages, said rotor flow passages providing a liquid flow path between the stator flow paths in communication with said second and third ports. When the valve is in said load position and a liquid flow path between the stator flow paths in communication with said second port and one of the pair of ports when the valve is in said inject position and a second rotor flow passage for providing liquid flow path between the stator flow path which is in communication with the other of said pair of ports and said cavity only when the valve is in said inject position, said rotor means further including seal means for sealing the cavity second end, said seal means defining an opening accessible from the valve exterior for facilitating the insertion of a syringe needle into said cavity therethrough for injecting a liquid sample into said sample loop through said cavity;
• and
• plug means for effectively closing the opening of said seal means, said seal means with said plug means being adapted to withstand said first pressure when liquid flows through said cavity at said selected pressure when said valve is in said inject position, said plug means comprising an elongated wire having a front portion thereof insertable into said cavity through the seal means opening to thereby close the latter, and a lockable plug holder connected to the wire end opposite the front portion which is insertable into said cavity.