A trocar system for endoscopic surgery, cap assembly, and related methods are provided. The cap assembly includes a housing with an opening formed in line with an axis of the housing. The cap assembly also includes a variable opening flexible sealing gland having a stack of valve body sections each including a valve extension extending from a valve ring and having a valve opening and a slit extending between a valve opening and the valve ring. The combination of the individual valve body sections forms a substantially conically shaped iris diaphragm portion of the sealing gland. The iris is positioned to individually and separately receive elongate tools so that when any one of the elongate tools is positioned through the valve opening, a seal is maintained between peripheries of the seal gland surrounding the iris and outer peripheries of the inserted elongate tool.