Closure for vessel or pipeline

An improved closure assembly for a pressure vessel or pipeline comprising a closure hub operatively coupled to the pressure vessel or pipeline wherein the closure hub is configured to provide communication thereto and a closure door configured to threadably couple to the closure hub and seal off communication to the pressure vessel or pipeline, the improvement comprising:

• a davit assembly operatively coupling the closure door to the closure hub, the davit assembly configured to support the closure door when the closure door is threaded off of the closure hub and to move the closure door away from the closure hub to provide access to the pressure vessel or pipeline, the davit assembly further comprising a davit nut threadably coupled to a threaded door pin extending outwardly from the closure door, wherein the door pin threads into or out of the davit nut as the closure door is threaded off of or on to the closure hub, respectively, wherein the davit assembly comprises:
• a standoff comprising first and second ends, the first end operatively coupled to the closure hub, the second end extending away from the closure hub, the second end comprising a hinge thereon,
• a substantially horizontal structural member rotatably coupled to the second end of the standoff and configured to rotate about a substantially vertical axis, wherein the substantially horizontal structural member comprises a hinge pin rotatably coupled to the hinge, the closure assembly further comprising a lock collar disposed on the hinge pin, the lock collar configured to provide vertical height adjustment for the davit assembly, and
• a substantially horizontal radial pin extending away from the substantially horizontal structural member, the radial pin operatively coupled to a davit nut assembly, wherein the davit nut is disposed in the davit nut assembly.