ASME B31J:2013 pdf free download

ASME B31J:2013 pdf free download.Standard Test Method for Determining Stress lntensification Factors(i-Factors) for Metallic Piping Components.
The ASME B31 Code for Pressure Piping and the ASME Boiler and Pressure Vessel Code, Section III, Nuclear Components, Subsections NC and ND piping rules require the use of stress intensification factors (i-factors or SIFs) when checking the adequacy of components and joints (welded and nonwelded) in piping subject to loadings, including those cyclic loadings that may produce fatigue failures. As used herein, where the word “Code” is used without specific identification, it means the Code or Standard which incorporates or references this Standard. The piping Codes provide stress intensification factors for the most common piping components and joints. This Standard presents an experimental method to determine SIFs.
2 DEFINITIONS
piping coniponents: mechanical elements suitable for joining or assembly into pressure-tight, fluid-containing piping systems. Components include pipe, tubing, fittings, flanges, gaskets, bolting, valves, and devices such as expansion joints, flexible joints, pressure hoses, traps, strainers, in-line portions of instruments, and separators. stress in?c,,sificatior, factor: a fatigue strength reduction factor that is the ratio of the elastically predicted stress producing fatigue failure in a given number of cycles in a butt weld on a straight pipe to that producing fatigue failure in the same number of cycles in the component or joint under consideration.
3 TEST PROCEDURE
3.1 Test Equipment
A schematic of a test arrangement is given in Fig. 3.1.
(a) The machine framework must be sufficiently stiff to precnt significant rotation at the fixed end of the assembly. A significant rotation is one readily visible to the observer.
(b) The pipe component shall be mounted close to the fixed end of the test assembly, but no closer than two pipe diameters.
The Codes for Pressure Piping (for example, ASME B31.1 and B3l.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 (3], and Markl (41 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 (5] discusses “Allowable Stress Range” and, in Appendices I and 2 of his paper, describes rules that were eventually incorporated in ANSI B31 .1-1955. 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., 1(1.255, + O,25S,)I are proportional to the fatigue strength of materials used in the components.