You really need to read and follow the code as there are specific requirements for vessel welds and what is stated above is only part of the answer. In general, yes can weld to a vessel that PWHT has been performed but there are limitations (i.e. total PWHT time) and conditions which have to be...
As long as you follow the design rules of section VIII you should be fine in using a hinged door. Is the door on the pressure side or the atmospheric pressure side and is the hinge just for handling the weight of the door during removal?
You did not post enough information for anyone to be able to answer your question. I assume the vessel is designed and built to ASME section VIII but this is not even stated. In some cases there are exemptions to mandatory PWHT but you have to be wihtin the code requirements. In short you need...
When I was a process engineer in the late 80's to early 90's we were welding high end military electronic assemblies (hermetic) with 400 watt Lumonics YAG lasers. We welded Aluminum, Stainless, and Kovar in a glovebox. I used quick change optics which was located about 80- 100mm above the work...
