FIGURE 3 - uploaded by Andre Nel
Content may be subject to copyright.
DESIGN NOZZLE LOADS [3] CURRENT DESIGN PRACTICE Cylindrical and Spherical Vessels The design of spherical and cylindrical pressure vessels subject to external loading is a well-documented and trusted procedure. The vessel shell can be designed for internal pressure according to UG-27 [2] and the junction reinforcement requirements can be checked using the area method in UG-37 [2] or the pressure-area method of Appendix 1-10 [2]. The stresses in the shell due to the external loadings can be obtained using WRC 107 [4] and the stresses in the nozzle using WRC 297 [5]. The local stresses in both the shell and nozzle may be obtained using WRC 368 [6]. This procedure allows for the safe design of a large proportion of vessel to nozzle junctions that are subject to external loading. If the junction geometry or external loading magnitudes fall outside the applicability criteria of the relevant section then the junction can be designed using FEA and the Design by Analysis rules given in Part 5 of ASME Section VIII Division 2 [7].  

DESIGN NOZZLE LOADS [3] CURRENT DESIGN PRACTICE Cylindrical and Spherical Vessels The design of spherical and cylindrical pressure vessels subject to external loading is a well-documented and trusted procedure. The vessel shell can be designed for internal pressure according to UG-27 [2] and the junction reinforcement requirements can be checked using the area method in UG-37 [2] or the pressure-area method of Appendix 1-10 [2]. The stresses in the shell due to the external loadings can be obtained using WRC 107 [4] and the stresses in the nozzle using WRC 297 [5]. The local stresses in both the shell and nozzle may be obtained using WRC 368 [6]. This procedure allows for the safe design of a large proportion of vessel to nozzle junctions that are subject to external loading. If the junction geometry or external loading magnitudes fall outside the applicability criteria of the relevant section then the junction can be designed using FEA and the Design by Analysis rules given in Part 5 of ASME Section VIII Division 2 [7].  

Source publication
Conference Paper
Full-text available
Dry air-cooled heat exchangers (ACHE) form an integral part of refinery cooling systems of which the header boxes form an important component. It is commonly designed as an ASME Section VIII Division 1 pressure vessel, but unfortunately neither ASME nor the American Petroleum Institute (API) provide guidance regarding to the methodology which shoul...

Citations

... A centering mandrel is introduced into the tube and the welding is performed. Studies can be found about this kind of heat exchanger in [25][26][27][28], but they are related to the design and analysis of the header box, especially the nozzle joints. ...
Article
Full-text available
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.