scholarly journals Analysis of Tube-to-Tubesheet Welding in Carbon Steel Heat Exchangers of a Double Plate Header Box

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 261
Author(s):  
José García González ◽  
Juan José Hernández-Ortega ◽  
Ana-Eva Jiménez-Ballesta ◽  
Rosendo Zamora Pedreño
Keyword(s):  
Carbon Steel ◽  
Heat Exchangers ◽  
Welding Process ◽  
Optimal Solution ◽  
Front Wall ◽  
Gas Tungsten Arc ◽  
Head Extension ◽  
Welded Tube ◽  
Steel Heat

The rear wall of the header box serves as a tubesheet in heat exchangers of double plate header box. Tube-to-tubesheet welding must be performed using orbital Gas Tungsten Arc Welding (GTAW) with a head extension, which is passed through the corresponding hole in the front wall (plugsheet) of the header box, where the welding machine is supported. In this project, the effect of parallelism deviations between the plugsheet and the tubesheet of carbon steel header box is analyzed to evaluate its influence on the quality of the tube-to-tubesheet welding. Welded tube (SA-210 Gr. A1) to tubesheet (SA-516 Gr. 70) coupons are manufactured simulating the parallelism deviations previously analyzed in two double plate header boxes of air-cooled heat exchangers using two different preheating temperatures. Macrographic analysis is performed in order to evaluate the weld penetration (minimum leak path) and length of the weld leg in tube-to-tubesheet joints. The results obtained show important variations in those parameters when the parallelism deviations are equal to or greater than −1 mm over the theoretical distance as well as when the distance approaches +1 mm or more. Finally, the incorporation of dimensional controls prior to the welding process is discussed and the implementation of improvements in orbital GTAW equipment is recommended as an optimal solution for this kind of heat exchangers.

scholarly journals Monitoring of Welding Process Parameters in Gas Tungsten Arc Welding of Carbon Steel Weldments

Mechanika ◽  
2019 ◽  
Vol 25 (1) ◽  
Author(s):  
Regita BENDIKIENE ◽  
Saulius BASKUTIS ◽  
Jolanta BASKUTIENE ◽  
Lina KAVALIAUSKIENE
Keyword(s):  
Carbon Steel ◽  
Process Parameters ◽  
Arc Welding ◽  
Welding Process ◽  
Gas Tungsten Arc Welding ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

scholarly journals THE OPTIMIZATION OF CLAMPING METHOD IN REDUCING WELDING DISTORTION OF LOW CARBON STEEL

2016 ◽  
Vol 20 (2) ◽  
Author(s):  
Heri Wibowo
Keyword(s):  
Carbon Steel ◽  
Test Specimen ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Bending Test ◽  
Angular Distortion ◽  
Welding Distortion ◽  
Low Carbon ◽  
Optimal Point

This study aimed to reduce levels of distortion welding through Clamping method so that the parameters of the most optimal Clamping against distortion and cracking resistance would be recognized. The method was applied to the workpiece Clamping before welding by 5 methods that include: without Clamping, 2 points Clamping, 4 points Clamping, 6 points Clamping and 4 points + fulcrum campling. The tests carried out on the workpiece welding include: distortions test (angles, curves and twisting) and shrinkage tests (transverse and longitudinal) and bending test for crack resistance. The results show that Clamping method is capable on reducing the level of distortion due to the welding process. Four Clamping method is considered the most optimal point in reducing the level of distortion with 2.2 angular distortion, 3.2 mm bending distortion, and without twist distortion. Bending testing shows that Clamping method does not degrade the quality of welded joints based on the acceptance of all bending test specimen

scholarly journals Laser welding of panel joints of stainless steel heat exchangers

2019 ◽  
Vol 91 (7) ◽  
pp. 7-19 ◽  
Author(s):  
Aleksander Lisiecki ◽  
Piotr Wójciga ◽  
Agnieszka Kurc-Lisiecka ◽  
Michał Barczyk ◽  
Sonia Krawczyk
Keyword(s):  
Stainless Steel ◽  
Laser Welding ◽  
Heat Exchangers ◽  
Mechanical Performance ◽  
Welding Process ◽  
Steel Plates ◽  
304 Stainless Steel ◽  
Aisi 304 ◽  
Basic Parameters

Results of study on the laser welding process of pillow plates heat exchangers are presented in the article. The influence of basic parameters of CO2laser welding on the quality of overlap joints of AISI 304 stainless steel plates 2.0 and 4.0 mm thick was determined. The range of optimal parameters of welding, providing the highest quality and high mechanical performance of the test joints was determined. The technological conditions elaborated during the study were applied for manufacturing of the real pillow plates heat exchangers with dimensions of 1.5 x 1.5 m.

Distortion control in multi pass dissimilar GTAW process using Taguchi ANOVA analysis

2018 ◽  
Vol 7 (3) ◽  
pp. 1140 ◽  
Author(s):  
Harinadh Vemanaboina ◽  
G Edison ◽  
Suresh Akella
Keyword(s):  
Welding Process ◽  
Fractional Factorial ◽  
Inconel 625 ◽  
Filler Wire ◽  
Gas Tungsten Arc ◽  
Distortion Control ◽  
Gtaw Process ◽  
Continuous Current ◽  
Arc Welding Process

The present study is to observe the distortion development in the weldment of Inconel 625 to SS316L multipass weldments. In this work two-level factors such as welding process, filler wire and root gap were employed with L4 orthogonal array. The welding has been carried out with continuous current and pulsed current gas tungsten arc welding process implementing ERNiCrMo-3 and ERNiCr-3 fillers rods respectively. The fractional factorial experimentation was analysis of variances (ANOVA), it was carried out to observe the critical parame-ter which influence distortion caused in the weldments. The quality of welds has been evaluated by X-Ray Radiography test. The results show that welding process and filler wire are contributing more in the distortion.  

Multifactor mathematical model of criticality of welding process of products from aluminum- magnesium alloys

2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina
Keyword(s):  
Mathematical Model ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Welding Process ◽  
Welding Equipment ◽  
Equipment Operation ◽  
Aluminum Magnesium Alloys ◽  
Aluminum Magnesium Alloy ◽  
Welding Materials

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]

scholarly journals Lumbar Roll Usage While Sitting Reduces the Forward Head Posture in Healthy Individuals: A Systematic Review with Meta-Analysis

2021 ◽  
Vol 18 (10) ◽  
pp. 5171
Author(s):  
Yusuke Handa ◽  
Kenya Okada ◽  
Hiroshi Takasaki
Keyword(s):  
Systematic Review ◽  
Meta Analysis ◽  
Grade System ◽  
Cochrane Library ◽  
Forward Head Posture ◽  
Quality Of Evidence ◽  
Head Posture ◽  
Head Extension ◽  
The Cochrane Library

This systematic review and meta-analysis investigated whether the use of a lumbar roll reduced forward head posture (FHP) while sitting among individuals with or without musculoskeletal disorders. EMBASE, MEDLINE, and the Cochrane Library were systematically searched from their inception to August 2020. The quality of evidence for variables used in the meta-analysis was determined using the GRADE system. Five studies satisfied the criteria for data analysis. All studies included individuals without any spinal symptoms. Data from five studies on neck angle showed a statistically significant (p = 0.02) overall effect (standardized mean difference (SMD) = 0.77), indicating a lesser neck flexion angle while sitting with a lumbar roll than without it. Data from two studies on head angle showed a statistically significant (p = 0.04) overall effect (SMD = 0.47), indicating a lesser head extension angle while sitting with a lumbar roll than without it. In each meta-analysis, the quality of evidence was very low in the GRADE system. The use of a lumbar roll while sitting reduced FHP among individuals without spinal symptoms.

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