Patent ID: 8794594

Claim:
A multiport gas chromatograph diaphragm-sealed valve comprising: a valve cap comprising a plurality of process conduits extending therethrough, each of the process conduits ending in a process port; a valve body facing the valve cap, the valve body comprising plunger passages extending therein and in alignment with the respective process conduits; a diaphragm positioned between the valve cap and the valve body, the diaphragm having temperature characteristics; and a plunger assembly comprising: a plunger-actuating mechanism located within the valve body; and a plurality of normally-closed and normally-opened plungers slidably fitting in the respective passages of the valve body, said plungers being simultaneously actuated by the plunger-actuating mechanism, each plunger comprising: a base member operatively connected to the actuating mechanism; an upper member projecting towards the diaphragm, for pressing the diaphragm in a closed position, or extending away from the diaphragm in an opened position, the upper member having a longitudinal play within a corresponding one of the passages with respect to the base member; and a resilient middle element provided between the base member and the upper member, said resilient middle element being made of a material which is based on the temperature characteristics of the diaphragm, the resilient middle element decreasing a sealing force on the diaphragm when the operating temperature of the valve increases, the force profile of the resilient element matching a varying pressure profile required to maintain proper sealing of the plunger on the diaphragm over an operating temperature range varying from 0 to 350° C. each of said plungers thereby providing an active temperature mechanical feedback loop when in use within the multiport gas chromatograph diaphragm-sealed valve.