GB1469171A - Purging of injection apparatus - Google Patents

Abstract

1469171 Syringes VARIAN ASSOCIATES 4 March 1974 [5 March 1973 (2)] 9566/74 Heading F1R A purging means in combination with injection apparatus which may comprise syringe 90 having a side port &c. comprises:-(a), means 380 Fig. 4, for supporting a container 240b for holding purging liquid with a head space above the liquid; (b), a first conduit 464, 466, Fig. 3, in operation extendable into container 240b and defining a first port 468 opening into the liquid, the first conduit in operation being communicable through the injection apparatus with a fluid, waste, receiver 202; (c), means for preventing communication between the first conduit and the fluid receiver, as in the embodiment shown in Fig. 2, by movement of plunger 92 of the injection apparatus syringe to close the opening of conduit 446 into the syringe barrel; (d), a second conduit 470 in use extendable into the container and defining a second port 478 opening into the head space over the liquid; (e) means for providing a controlled quantity of purging liquid through the injection apparatus comprising Fig. 4, an accumulator 502 for storing a predetermined volume of gas at a predetermined pressure; (f), means 508, 510 for providing a gas supply to the accumulator; (g), means for providing communication from the accumulator to the second conduit and (h), first and second valves 504, 506, the first valve 504 providing communication either (i) between gas supply means 508, 510 and the accumulator 502 or (ii) between accumulator 502 and the second conduit 470, via 520, and the second valve providing (i) communication between container 240b and the atmosphere or (ii) closing conduit 470, 520 from the atmosphere, the gas discharging from the accumulator to the head space of the container when the valves are in their (ii) states, the gas forcing purging liquid through conduit 464, 466 to purge the injection apparatus. In use, plunger 92 is moved to close the side arm connection to conduit 466, 646, the pair of conduits 464, 470, Fig. 3, is inserted into container 240b through its covering septum, valve 506 is operated to vent the head space of the container to atmosphere via 478, 470 520, 506, the accumulator 502 is charged by opening valve 504 to the supply line 508, the purging liquid in the container is pressurized by operating valve 504 to connect the accumulator and the container and plunger 92 of the syringe is retracted to provide a path for flow of pressurized purging liquid from container 240b through conduit 464, 466 and through the syringe to waste receiver 202.