Increased Allowable Stresses for Earthquake and Wind Loads in Section VIII, Division 1

Abstract

There has been a need for some time to provide rules for allowable stresses for short-time and infrequent loading such as earthquake and wind loads in Section VIII, Division 1 of the Boiler and Pressure Vessel Code. Such rules exist in Section VIII, Division 2, in Section III, and in many other Codes. Division 1 has been silent on the subject. This has caused some manufacturers to make their own rules, and some to overdesign their hardware. Neither situation is without problems. Therefore, in 1979 the Boiler and Pressure Vessel Committee undertook to develop rules for Section VIII, Division 1. This work resulted in the addition of paragraph UG-23(d) to the Code, in the Summer, 1983 Addenda. The paragraph permits an increase in general primary membrane stress of 20 percent for earthquake and wind loads for temperatures below the creep regime.