Revised stress multiplier rules ASME boiler and pressure vessel code section viii-division 1 1986 addenda

摘要

Included in the December 31, 1986 Addenda to the 1986 ASME Boiler and Pressure Vessel Code, Section VIII-Division 1, were major revisions to the rules relating to stress multipliers, the consideration of which was initiated as the result of userinquiries stemming from the complexity of the then-current rules. These revisions reflect an effort by the Special Working Group -Stress Multipliers (SC-VIII) to clarify and simplify the existing rules by eliminating the combined use of two interrelated factors -- stress reduction and joint efficiency -- to represent the strength of the welded joints in an entire vessel, and by adopting more rational rules based upon a slightly modified consider-each-joint-separately approach. The "heart" of themodifications made to the "pure'1 consider-each-joint-separately concept is covered in UW-11(a)(5), and the joint efficiencies resulting from these rules are covered in UW-12. The appropriateness of continuing to limit the application of jointefficiencies to Table UW-12 joints only was reaffirmed; thus, the new rules continue to reflect this approach. The Special Working Group is continuing their work, addressing additional refinements and clarifications, some of which will likely be included in future Section VIII-Division 1 Addenda.