It not often I come across a 70+ year old PV still in pristine condition. Below is the name plate for this vessel and it carries an interesting code compliance story. As I said, it’s not often to find a NH3 storage vessel this old and because of its age, it carries some SPECIAL PRV exemptions…
CGA 2.1
5.8.1.5
Container pressure relief valve shall be set to discharge at no more than 125% MAWP for containers built by the 1949 ASME Code Sections U-68 and U-69, and no more than 100% for those built by all subsequent ASME Codes [18]. Set pressure tolerance is +10% to 0% for nonrefrigerated containers.
