AWS D14.4-D14.4M:2012 pdf download.Specification for the Design of Welded Joints in Machinery and Equipment
1.1 General
This specification sets forth requirements dealing with the allowable stresses, welded joint design, workmanship, proce-dure and performance qualification, inspection, repair and post weld treatments of welded connections used in machin-ery and equipment, subject to static and cyclic loading. It is intended to be used in conjunction with other specifications that provide application specific requirements (such as D14.1, D14.3, etc.). In the event a conflict arises between the application specific standard and AWS D14.4/D14.4M, the application specific standard shall take precedence. The intent of this document is to establish the effect of weld joint geometry, welding practices, and quality control on allowable stress levels. The specification also provides practices that can be used for examination of welded joints used in fabrication of machinery and equipment.
1.2 Limitations
This specification does not dictate load determination, design assumptions, safety factors, or calculation methods. It is not the intent of this specification to restrict the use of other proven welding methods and procedures that are not mentioned herein, which achieve acceptable results and which have been agreed to in writing by the Owner and Manufacturer.
1.3 Units of Measurement
This specification makes use of both U.S. Customary Units and the International System of Units (SI). The measurements may not be exact equivalents; therefore each system must be used independently of the other without combining in any way. The specification with the designation D14.4 uses U.S. Customary Units. The specification D14.4M uses SI Units. The latter are shown in appropriate columns in tables and figures or within brackets [ ] when used in the text. Detailed dimensions on figures are in inches. A separate tabular form that relates the U.S. Customary Units with SI Units may be used in tables and figures.
5.5.1 The minimum overlap of parts in principal structural weldments, lap joints shall be five times the thickness of the thinner part, but not less than 1 inch [25 mm]. Unless lateral deflection of the parts is prevented, they shall be double fillet welded or joined by at least two transverse lines of plug, or slot welds or by two or more longitudinal fllet or slot welds.
5.5.2 If longitudinal fllet welds are used alone in lap joints of end connections, the length of each fllet weld shall be no less than the perpendicular distance between them. The transverse spacing of longitudinal fillet welds used in end connections shall not exceed 16 times the thickness of the connected thinner part, unless suitable provision is made (as by intermediate plug or slot welds) to prevent buckling or separation of the parts. The longitudinal fillet welds may be either at the edges of the member or in slots.AWS D14.4-D14.4M pdf download.