In a 12F production tank, has anybody seen a detail where there is a single additional horizontal 18" long fillet weld to the roof/shell joint located over a vertical shell joint? The stated purpose of this detail is to provide a reinforced hinge such that the roof comes off in an explosion, but hinges over at this spot (or the roof is perhaps flung a lesser distance...) My calculations indicate the joint strength is governed by the 3/16 base metal thickness in the shell; more weld material will not provide any more strength. Thanks in advance for any responses.