... set is optional. 2,Vacuum PluggingB---After filling, the syringe is delivered to the vacuum chamber manually. When the vacuum ... –vacuum sucking- nitrogen flush, then plug the stopper inside the syringe .The vacuum degree can be displayed digitally, and adjustable according ... of the surfaces. All the contact parts i.e. filling pumps, filling nozzles, the transferring hoses, Nitrogen flushing tubes and ...