Repair of tubetubesheet weld cracks in a cracked gassteam heat exchanger article pdf available in journal of failure analysis and prevention 116 december 2011 with 5,950 reads. Strengthweld tubes to tubesheet process heat transfer. Experience gained from user contact and welding training of crewmembers showed that. I need to check the ligament efficiency of the tubesheet in order to determine if it can handle the forces imposed by the welding process. Tubetotubesheet welding tubetotubesheet welding, employing a tig process with shielding gas, is strongly recommended when using thinwall tubing under 22 bwg0. This oneday training course is a basic introductory overview of the section ix welding requirements code book. It is design for compact automatic wire feeding system on ots80 weld gun. The root cause of the cracks is mainly attributed to poor workshop in the tubetubesheet welds. Pdf repair of tubetubesheet weld cracks in a cracked gas. Dear experts, i need to do tube to tubesheet welding for cs steel that is tubesheet material is sa 516 gr. Tube totubesheet welding development programs for 30.
Special welding techniques for joining inconel weld overlays on type 316 stainless steel tubesheets and channels are described. Explosive welding tubes to tubesheet rmw mechanical 30 sep 10 21. For a vertical heat exchanger where the stationary tubesheet is at the bottom. Tubetotubesheet weld qualification american welding society. Explosive welding tubes to tubesheet welding, bonding. Peanut behind the joystick for the gtaw machine tube to tubesheet welder at work. Sep 17, 2010 if your tube to tubesheet joint fall in uw20. Type 316 stainless steel overlaid to a thickness of 14 inch with two layers of inconel filler metal 82 using the developed inert gas shielded metalarc process. The cause of the failure has been analyzed, and the exchanger is repaired. We are a specialist heat exchanger manufacturer in suratgujarat state india. We provide a fast ultrasonic technique, which does not require special safety procedures prior to or during inspection, for detection of weld defects in tubetotube sheet welds. If it is of fillet weld type,then you have to follow appemdixa,and need to qualify with shear load test.
Three models cover the size range of 10 to 140 mm 0. Topic welding industry technical discussions repair of tube to tube sheet welding by ukverma date 05242005 18. Strengthweld tubes to tubesheet posted in process heat transfer. Gas welding and cutting oxyfuel welding, commonly referred to as oxy welding or gas welding is a process of joining metals by application of heat created by gas flame. Mockup of 10 tubes about 305 mm 12 long are welded to a portion of a tubesheet, using the same welding procedure, cut and polish for macro test. In addition to this, the weld also had a natural defect got introduced in it during welding. Repair of tubetubesheet weld cracks in a cracked gassteam heat exchanger article pdf available in journal of failure analysis and prevention 116 december 2011 with 6,082 reads. Different manual welding methods arc welding, spot welding etc. Tube to tubesheet welding machine manufacturer,supplier. A variety of methods are used for making the joint between the tubesheet and the tubes. Tube to tubesheet welding is qualified by welding ten mockups of the tube to tubesheet joints using the same geometry holes in the tubesheet and the same tube. The purpose of the welding handbook for maritime welders is to provide guidance in modern welding and related processes and to provide the welder with a source of practical information on the right solution to specific onboard welding problems. Repair of tubetubesheet weld cracks in a cracked gas.
Recommended for high stress tubetotubesheet joints. The process parameters of welding include pre purge time, up slope, speed of welding, down slope, post purge time. A shelltube heat exchanger was found failed when it was used about 30 days after assembling. Hi, i have been going through one of the shell and tube exchange data sheet and at the end one note was mentioned saying strengthweld tubes to tubesheet. In connection with an orbitalum orbital welding power supply, the user is being offered an extremely innovative and economical welding system. From the comparison between high pressure and low pressure leak test, generation of indication, or tube to tubesheet weld quality, of songs rsgs are similar to the past rsgs. Tube to tubesheet welding joint in progress for refinery grade heat exchanger. Mechanical engineering assignment help, what is mockup testing, q. Tube to tubesheet welds cweng materials 5 may 16 00. The ots series orbital tube to tubesheet weld head is design for fabrication of various heat exchangers and boiler industry. Ots80 orbital tube to tubesheet orbital welder is widely applied into boiler, exchanger, and cooler industrial.
These indications were in the tubetotubesheet weld and were not visible during visual inspections of the weld. Tubetotubesheet orbital weld heads orbital welding. Tubes are either generally drawn and seamless or welded. The repair to leaking tube by welding was tried but in vain as this opens up the adjacent welds and worsen the situation. Fundamentals of gas cutting and welding ced engineering. Gasshielded arc welding of aluminium gasshielded welding can be divided into the tungsten gasshielded welding and the. Welding is a core process for most manufacturing projects and now advanced automated solutions are becoming a common sight in various industrial facilities. It is common to use tubing from 58 to 112 in these designs. Tubesheet weld heads orbital pipe welding equipment. But how we decide that we need to specify strengthweld tubes to tubesheet. Hello everybody, we are planning to conduct procedure qualification for welding tubetotubesheet partial penetration strength weld of hex. Sep 16, 2010 the weld in a tube to tubesheet joint meets the requirements of uw20. Tdm has many types of mockups for strength welding including. Repair of tubetubesheet weld cracks in a cracked gassteam.
Tube expanding and welding for boiler fabrication kranendonk. It is geared for accessibility by people who are approaching section ix for the first time, as well as providing useful information to those with more code experience. Tubetotubesheet welding development programs for 30. Failure analysis of tubetubesheet welds in cracked gas. The joining technique must lend itself to mass production and to uniformity of quality. Alloy 20, c276, 2205, monel 400, nickel 200, al6xn, 9010 cuni. For some serious positions, the tube ends were broken down from the tubesheet. With our tig weld heads, it is no longer a problem to weld tubes to tubesheets with the highest of accuracy and consistent quality. A welding application specialist in your area will advise you on the welding process and appropriate equipment for your application. It can be used for recessed, projected and flush tubing with or without wire feed. Emphasis here is on fabricating the tubesheet, inserting the tube ends and securing them in the tubesheet holes whether by expanding only, welding only or a combination of expanding and welding. Flux cored wires, controlled dc arc welding machines, arc. Chapter 3 introduction to welding in the navy as well as private industry, welding is widely used by metalworkers in the fabrication, maintenance, and repair of parts and structures. All orbitalum orbital welding power sources automatically detect the head and its properties so that the.
So, we have chosen to go for qualification by groove weld as per asme ix qw202. Magnatech tubesheet heads are designed to make tubetotubesheet welds with precision and repeatability. Due to the poor quality tube to tubesheet weld joint which is light expanded and strength welded construction, the ammonia gas leaks from few tts welds and forms salt deposits on the tubesheet. The models 424 and 425 provide for filler wire addition. While welded expanded joints are the most leak resistant, hydrogen may pass through welded joints. Tube to tubesheet welds asme mechanical code issues.
Tubetotubesheet welding is qualified by welding ten mockups of the tubetotubesheet joints using the same geometry holes in the tubesheet and the same tube. Welding was improved by avoiding tool contact with the tube plug or the. Amis proven tube sheet weld heads provide productivity and ease of. The tswh3 tube to tube sheet weld head is designed for tig welding tube to tube sheet, suitable for carbon and stainless steel. These indications were in the tube to tubesheet weld and were not visible during visual inspections of the weld.
From the comparison between high pressure and low pressure leak test, generation of indication, or tubetotubesheet weld quality, of songs rsgs are similar to the past rsgs. Each of the above type of welding can be further classified depending on other micro level characteristics. Avc function is standard on the more complex heads. Jun 17, 2015 strengthweld tubes to tubesheet posted in process heat transfer. This type of edge weld may also be used for tube to tubesheet welding where, by machining a pintle onto the tubesheet, the tube can be inserted through the tube hole and an edge weld made, fig. Hello everybody, we are planning to conduct procedure qualification for welding tube to tubesheet partial penetration strength weld of hex. Failure analysis of tubetotubesheet welded joints in a. As published in the welding journal, april, 2007 prepared by. I need to do tube to tubesheet welding for cs steel that is tubesheet material is sa 516 gr. As published in the welding journal, april, 2007 prepared. In tubesheets of limited weldability or where postweld. We provide a fast ultrasonic technique, which does not require special safety procedures prior to or during inspection, for detection of weld defects in tube to tube sheet welds. This welding head is specially designed tig welding head for header box tube to tubesheet.
Sound welds were achieved in the fsw of astm 179 seamless colddrawn carbon steel tube into an astm a516 grade 70 tubesheet. Tubesheet weld heads orbital welding equipment automated welding equipment these magnatech weld heads are specifically designed for making tube to tubesheet welds. All orbitalum orbital welding power sources automatically detect the head and its properties so that the operator only. Shell and tube heat exchanger with welds joining the tubes. Multifunction buttons like stopstart weld, rotation, wire feeding, which are all integrated on this weld gun handle for quick and easy operation. Weld heads can be configured with a wide selection of torches and configurations to match all common tube sheet design. These rules are very similar to those found in section viii, division 2, article f3 and identical to the rules in section iii, nbcd4350. Titanium welding process of a tubetube sheet joint. Tube to tubesheet weld heads for autogenous or with filler wire welding. Tube to all tubesheet weld tests shall be provided as described below. Dozens of leak points were found near the tubetotubesheet welded joints of the shelltube heat exchanger. Such a system is used for rolling of tube to tubesheet connections and the cleaning and end face milling of tubes.
As i understand this note is to prevent the leakage from shell side to tube or tube to shell side. Gas metal arc welding gmaw, by definition, is an arc welding process which produces the coalescence of metals by heating them with an arc between a continuously fed filler metal electrode and the work. Magnatech tubesheet heads are designed to make tube totubesheet welds with precision and repeatability. Pdf repair of tubetubesheet weld cracks in a cracked. The indication in the tack expansion the region of the tube expanded into the tubesheet to facilitate welding was approximately 0. In the first group, all kinds of pipe connections are included. Heat transfer by heat exchangers tubes and tubesheet piping. Failure analysis and repair procedure were reported in the present article. Failure analysis and repair procedure were reported in the present. Dozens of leak points were found near the tube to tubesheet welded joints of the shell tube heat exchanger. It can weld carbon steel, stainless steel, and indentedflush tube to tubesheet connection. Serious cracks were found at tubetotubesheet welds during the start up operation of a cracked gassteam heat exchanger in a gas plant. Automated laser beam welding of tubetube sheet joints fraunhofer.
The weld quality with respect to shape and soundness are controlled by process parameters. Quality requirements for fusion welding of metallic materials. A shell tube heat exchanger was found failed when it was used about 30 days after assembling. Tube to sheet processing cell besides the welding of tube to tubesheet connections, kranendonk also has supplied complete systems for tube expanding. It is imperative when employed in a clad or bimetallic tubesheet arrangement. The process uses shielding from an externally supplied gas to protect the molten weld pool.
Configured for fast and simple operation, the head is inserted into the tube to be welded, and the operator pushes the start weld switch. Good day, im looking at using the explosive welding technique to weld a tube bundle to a tubesheet or header for feedwater heaters. Tube to tubesheet welding tube to tubesheet welding, employing a tig process with shielding gas, is strongly recommended when using thinwall tubing under 22 bwg0. When welding the tubes to the front face of the tubesheet for tightness or strength, subsequent expanding beginning about 38 to. The program for the development of the required welding procadures are divided into three specific progranns. Mar 24, 20 peanut behind the joystick for the gtaw machine tube to tubesheet welder at work. Tubesheet weld heads orbital welding equipment automated welding equipment these magnatech weld heads are specifically designed for making tubetotubesheet welds. It can also be used for recessed, projected and flush tubing with or without wire feed. Mockup of 10 tubes about 305 mm 12 long are welded to a portion of a tubesheet, using the same welding procedure, cut and polish for macro t. Most of the indications were existed at this is the nature and. Root cause analysis of indications of tubetotubesheet welds. Supplementary specification to api standard 660 shelland. Jun 28, 2012 tube to tubesheet welding joint in progress for refinery grade heat exchanger.
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