@ Txxxxx January 11 at 02:12am Sir kamusta na po kayo? Sir, can you help me in identifying the welds in the products by the welders as it was asked by my superior and I was not able to clearly identify the clause in the Pressure Vessel Construction Code? XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Hi Txxxxx I am doing fine! Just recently conducted a QA-QC Course which I hope you can attend when youre back in Manila. Here goes your answer:......... Although stamping is Not Permitted is the ASME VIII in Forging/Forged as this will cause a stress riser, It cant be easily done without proper procedure (e.g. if it is located near the welding reinforcement that will and might cause crack during service of the Pressure Vessel especially when in comes to carbon steel due to stress. Such example is thermal stress if it designed for high temperature and if not design for high temperature but was somehow subjected to high temperature creep might occurs in the base metal near the weld metal.) Stamping of Welder Identification can be done provided shall be specified by the Company/Builder in their QA-QC System or QMS verified by the Inspector. UW-37 MISCELLANEOUS WELDING REQUIREMENTS (f) Welder and Welding Operator Identification (1) Each welder and welding operator shall stamp the identifying number, letter, or symbol assigned by the Manufacturer, on or adjacent to and at intervals of not more than 3 ft (1 m) along the welds which he makes in steel plates 1⁄4 in. (6 mm) and over in thickness and in nonferrous plates 1⁄2 in. (13 mm) and over in thickness; or a record shall be kept by the Manufacturer of welders and welding operators employed on each joint which shall be available to the Inspector. For identifying welds on vessels in which the wall thickness is less than 1⁄4 in. (6 mm) for steel material and less than 1⁄2 in. (13 mm) for nonferrous material, suitable stencil or other surface markings shall be used; or a record shall be kept by the Manufacturer of welders and welding operators employed on each joint which shall be available to the Inspector; or a stamp may be used provided the vessel part is not deformed....................................... (f) Welder and Welding Operator Identification (3) Permanent identification of welders or welding operators making tack welds that become part of the final pressure weld is not required provided the Manufacturer’s Quality Control System includes a procedure to permit the Inspector to verify that such tack welds were made by qualified welders or welding operators. zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz Other Objective reference: ASME BPVC VIII - 2010 Division 1 Rules for Construction of Pressure Vessel MANDATORY APPENDIX 22 INTEGRALLY FORGED VESSELS 22-3 DESIGN (1) The shell portion shall have no stress raisers, such as openings, welded attachments, or stamping, except for identification stamping on the forging material prior to heat treatment. ASME BPVC VIII - 2013 Division 1 Rules for Construction of Pressure Vessel PART UF REQUIREMENTS FOR PRESSURE VESSELS FABRICATED BY FORGING UF-12 GENERAL Vessels constructed of SA-372 Grade A, B, C, or D; Grade E, Class 65 or 70; Grade F, Class 70; Grade G, Class 70; Grade H, Class 70; Grade J, Class 65, 70, or 110; Grade L; or Grade M, Class A or B must be of streamlined design, and stress raisers, such as abrupt changes in section, shall be minimized. Note: Creep damage may occur if equipment is subjected to temperatures above those for which the equipment is designed. Since metals become weaker at higher temperatures, such distortion may result in failure, particularly at points of stress concentration. If excessive temperatures are encountered, structural property and chemical changes in metals may also take place, which may permanently weaken equipment. Since creep is dependent on time, temperature and stress, the actual or estimated levels of these quantities should be used in any evaluations. SORRY FOR THE LATE REPLY!!!!!!!!!!!!! I hope I was able to answer your query.
Posted on: Mon, 12 Jan 2015 08:41:56 +0000