Considerable progress has been made in welding technology both in terms of developing new processes and improving older methods. Application of newer methods to refinery construction is considered, particularly electroslag and CO2 welding, together with developments in the older techniques.
Problems arising with special materials such as low alloy steels used for heavy pressure vessels, quenched and tempered steels and high temperature materials are reviewed, as are recent developments in the application of welding to particular items such as piping, vessels, heat exchangers and tankage.
Des progrès considérables ont été faits dans le domaine de la technologie du soudage aussi bien que dans le développement de nouveaux procédés que pour l'amélioration des méthodes plus anciennes. On envisage, l'application de nouvelles méthodes pour la construction de raffineries et, en particulier, le soudage électrique sous laitier et sous CO2 avec les développements des techniques plus anciennes.
Les problèmes qui surviennent dans le soudage des matériaux spéciaux, tels que les aciers à faible teneur en alliage utilisés pour des grands récipients sous pression, les aciers trempés à l'eau et revenus et les matériaux de haute température sont passés en revue ainsi que les récents développements de l'application du soudage à certains matériels tels que tuyauterie, récipients, échangeurs de chaleur et réservoirs.
The general increase in scale of petroleum refineries and petrochemical plant, and the reduced capital cost of single-stream operation, have combined to generate a demand for large pressure vessels. In the case of reactors operating at elevated temperature and/or pressure, the increase in scale gives rise to special problems.
On the one hand, site fabrication of such vessels is more difficult because of the potential hazard of welding thick sections of plate and forgings under site conditions: on the other hand, shop handling and transportation facilities limit the weight of vessels that can be shop fabricated. This limitation is more severe in Western Europe than it is in the United States: whereas in the U.S.A. it is possible to shop fabricate and transport vessels up to 1,000 tons in weight, European conditions impose a maximum weight in the region of 250 by W. B. HOYT, The M. W. Kellogg Company, (U.S.A.)., and J. F. LANCASTER, Kellog International Corporation, United Kingdom. tons. For large shop fabricated vessels operating at high pressure there is, therefore, an incentive to select materials of high tensile strength, particularly if the vessel is fabricated or transported (other than by sea) in Western Europe.
At the same time, the possibility of fabricating such vessels by welding solid plate has become generally accepted. In times past ammo
