Needle assemblies (100, 400, 600) and related methods in which a valve opener (134) is used to push into a valve (136) to open one or more slits (324) on the valve (136) to open the valve (136). The needle assemblies (100, 400, 600) each includes a needle hub (106) with a needle (108), a catheter tube (104) with a catheter hub (102) and the valve (136) and valve opener (134) positioned in the interior cavity (130) of the catheter hub (102). The valve (136) can have a valve skirt (412) and a nose section (430) of the valve opener (134) can locate therein. One or more reliefs (61, 448) can be provided with the valve opener (134) so that an elbow or diagonal section (304) on a needle guard (132) can project from a holding space (155, 720) within the valve opener (134) through the relief (61, 448).
