ASME B31J:2008 pdf free download

ASME B31J:2008 pdf free download

ASME B31J:2008 pdf free download.Standard Test Method for Determining Stress lntensification Factors(-Factors) for Metallic Piping Components.
The Codes for Pressure Piping (for example, ASME B31.1 and 831.3; ASME BPVC, Section III, Class 2/3) use stress intensification factors (i-factors) for various piping components and joints as a measure of their fatigue performance relative to girth butt welds. Occasionally, a need arises to establish i-factors for components not included in the Codes, such as a branch connection in an elbow or some proprietary piping component. This Standard provides a set of requirements that will ensure that newly developed i-factors will be consistent with the existing i-factors.
(a) Papers by Markl [2], Markl and George 131, and Markl 141 provided the basis for most of the i-factors in the Codes. Key aspects of the testing and interpretation of test results are as follows:
(1) a preliminary load-deflection plot was developed (see Fig. 3.3)
(2) cyclic bending tests were run with controlled displacements
(3) failure was defined as a through-wall crack (4) the i-factor was calculated by eq. (3)
(b) Markl 151 discusses “Allowable Stress Range” and, in Appendices 1 and 2 of his paper, describes rules that were eventually incorporated in ANSI B3L1-1955. These rules are essentially unchanged. This paper discusses the following three concepts that are fundamental to the use and interpretation of i-factors as a control of fatigue failure:
(1) the i-factors are dependent upon dimensions and are independent of the material
(2) as a consequence of (1), i-factors developed by Markl using ASTM A 106 Grade B material are presumed to be applicable to components made of any of the metallic materials listed in the Piping Codes
(3) the Code stress limits [e.g., fl1.25S + O.25S,)] are proportional to the fatigue strength of materials used in the components
(c) Materials and Material Extrapolations. Markl ran tests on specimens made of ASTM A Grade B material. Paragraph 3.2 prescribes analogous Grade B materials. It is recognized that some components may not be made from Grade B materials,e.g-, a copper tubingfitting. If tests were run, for example, on a copper elbow,then a different C constant would be needed so that theconcept that i-factors are independent of the materialwould be preserved. Section 3 is written to allow this,with rules provided in section 5.