ASME B31J:2008 pdf free download

ASME B31J:2008 pdf free download Standard Test Method for Determining Stress Intensification Factors (i-Factors) for Metallic Piping Components
1GENERAL
The ASME B31 Code for Pressure Piping and theASME Boiler and Pressure Vessel Code,Section III,Nuclear Components,Subsections NC and ND pipingrules require the use of stress intensification factors(i-factors or SIFs) when checking the adequacy of com-ponents and joints (welded and nonwelded) in pipingsubject to loadings, including those cyclic loadings thatmay produce fatigue failures.As used herein, where theword “Code” is used without specific identification,itmeans the Code or Standard which incorporates or refer-ences this Standard.The piping Codes provide stressintensification factors for the most common piping com-ponents and joints.This Standard presents an experi-mental method to determine SIFs.
2DEFINITIONS
piping components: mechanical elements suitable for join-ing or assembly into pressure-tight, fluid-containingpiping systems. Components include pipe, tubing, fit-tings, flanges, gaskets, bolting, valves, and devices suchas expansion joints, flexible joints, pressure hoses, traps,strainers,in-line portions of instruments, and separators.stress intensification factor: a fatigue strength reductionfactor that is the ratio of the elastically predicted stressproducing fatigue failure in a given number of cyclesin a butt weld on a straight pipe to that producing fatiguefailure in the same number of cycles in the componentor joint under consideration.
3TEST PROCEDURE
3.1 Test Equipment
A schematic of a test arrangement is given in Fig.3.1.(a)The machine framework must be sufficiently stiffto prevent significant rotation at the fixed end of theassembly.A significant rotation is one readily visible tothe observer.
(b)The pipe component shall be mounted close to thefixed end of the test assembly, but no closer than twopipe diameters.
(c)The test rig shall be capable of applying a fullyreversed displacement at the free end without binding
in the two orthogonal directions. That is, the free endshall not bind the assembly in a direction out of theplane of testing.
(d) The test equipment shall be calibrated to read dis-placements with an accuracy of 1% of the imposed dis-placement amplitude.
(e)The piping attached directly to the tested compo-nent should be a similar schedule to the tested com-ponent.
3.2 Test Specimen
The test specimen may be lower strength carbon steel,such as ASTM A 106 Grade B pipe or ASTM A 234Grade WPB fittings, and equivalent plates and forgings,corresponding to the “UTS<80 ksi" curve in Fig.5-110.1of Appendix 5 of Section vII, Division 2 of the ASMEBoiler and Pressure Vessel Code. For other materials,the material constant,C, shall be modified as describedin para.5.1. The fabrication, welding, and examinations of thetested components shall be the same as will be followedin fabrication of the component and installation for ser-vice. Weld contours should be representative of thoseintended to be used in fabrication and installation.3.3 Applied Displacement Calibration (a)The test specimen shall be placed in the test assem-bly and displacements shall be applied in positive stepsto obtain a load-displacement plot analogous to thatshown in Fig. 3.3.At least five points shall be recordedin the linear region of the plot. (b) The initial loading sequence shall be stoppedwhen it is clear from the load-displacement plot that therecorded load displacement is no longer linear,i.e., theloading sequence will require one or two steps into thenonlinear range. (c) The specimen must then be unloaded, followingthe same recording sequence as during loading. (d) Steps (a) through (c) are repeated in the negativedirection to approximately the same negative displace-ment as the loading sequence reached in (b). (e)The linear region of the load-displacement curveand its straight-line extension will be used in determin-ing the force, Fe, in para. 4.1.