#$%^&*AU2018200384A120180208.pdf#####ABSTRACT A piston for a needleless valve system comprising a head portion configured to be disposed in the needleless valve system and controlling fluid flow through the needleless valve system. The head portion comprising a continuous top surface, and an opening disposed proximate the continuous top surface, wherein the continuous top surface is non-planar when the opening is in an open position.4/5 300 410 122 310 320 110 330 355 130 FIG. 4