Patent ID: 8308011

Claim:
A closure for a pressure vessel, comprising: a shell sub adapted for mounting to the pressure vessel, the shell sub defining an opening; a closure head sealingly engageable with the shell sub for closing the opening; a yoke having a plurality yoke sections that are moveable radially outwardly and inwardly relative to the opening; at least one securement assembly operably connected to adjacent yoke sections and operable to drive the adjacent yoke sections radially outward and inwardly, each securement assembly including: (a) a drawbolt having first and second sections of opposite hand threading, the drawbolt having a first bolt head; (b) a second bolt, the second bolt having a second bolt head, wherein the first and the second bolt heads are of a common wrench interface size; and wherein at least one securement assembly comprises a third bolt having a third bolt head, wherein the third bolt head is of the common wrench interface size as the first and the second bolt heads.