sections 108 that define weaknesses along which the sheath tube is easily split by the practitioner after insertion of the catheter 39 s distal portion into the vasculature of a patient not shown referring primarily first to fig3 a sheath hub 110 is affixed to the proximal end portion 104 of the sheath tube at the distal end portion 112 of the hub a pair of wings or tabs 114 extend from respective opposed sections 116 118 of hub 110 for gripping by the practitioner for initiating the splitting of the sheath assembly for tearing it away from the catheter by their being pried toward the sheath distal end such that the splitting of the hub begins at its proximal end 120 and separating hub sections 116 118 completely from each other along a pair of opposed gaps 122 also seen in fig3 is a portion of a frangible section 124 disposed along the inside edge of gap 122 the frangible section or webs on both sides join together the two hub sections 116 118 now referring to fig4 hub 110 is exploded from sheath tube 102 splittable valve 150 is exploded from hub 110 and the two halves 182 of cap 180 are exploded from hub 110 and valve 150 hub 110 includes a large diameter cylindrical portion 126 extending to its proximal.