COMPUTER- AIDED QUALITY CONTROL OF WELDED GAS PIPELINE USING EXPERT SYSTEMS TECHNIQUE

Abstract

The present research employs an expert system with a view to increase the weldink quality. Its major aim is to produce a better welding quality so as to reduce the production costs, save time and spare the effort exerted in treating the common I . I welding defects. This is a fundamental issue due to the tremendous technologyical an4

i

economic progress in industry that

dominates ihe modern age. Thus, preventing the I

welding defects has become urgent in this respect in order to incease produtivity by

rducing production cost and increasing the welding quality.The major part of this study ' I is an experimental one applied to the duplication of Gas pipeline (diameter 16 inches

and length about 190 Kilometers ) Ras Bakr I Suez project. After welding manuall I

by shielded metal - arc welding according to API. II 04 ( American Petroleum

Institute), they were tested by radiographic test according to specific code. If any, i defects appear they must be repaired and retested according to API code. The result otl analysis is that hollow - bead, slag inclusion and porosity are the most common welding defects They represent 73 % ; Hollow c bead 32% ; slag inclusion 23% and porosity 18% of the total welding defects. The result of studying defects location is that two of the welding defects (hollow- bead and porosity) are located between 2:30 and 4.00 O'clock position and between 8.00 and 10:30 O'clock position. Welding in these

positions is difficult and needs skillfully trained welders. Slag occurs in different

positions. Its common cause is carelessness in deslagging a previous layer of welded , I

metal. Therefore, proper cleaning and deslagging are essential prior to welding any !, additional beads. The previous method is introduced in computer software by using expert system•s to give feedback day by day.