PSI - Issue 13

M. Amara et al. / Procedia Structural Integrity 13 (2018) 2137–2142 Author name / Structural Integrity Procedia 00 (2018) 000–000

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a)

b) Fig. 6. Erosion rate for different angles (a) 15°, (b) 30°

c)

d) Fig. 7. Erosion rate for different angles (c) 45°, and (d) 90°

Table 2. Recapitulation of the different parameters of the fitting equation Equation A t B R 2 Y angle 15° 3,72674E10 0.03895 5,40401 0.991 Y angle 30° 3,5487E11 0.0475 6,96352 0.996 Y angle 45° 1,18398E11 0.0475 10,70968 0.990 Y angle90° 6,83187E8 0.0475 4,95954 0.997

Fig. 8. The thickness degradation on the elbow steel (a) and the affected zone near the valve for the angle of 15° and 30° (b),(c) respcetively. 3.4. Effect of shear stress on the elbow Erosion-corrosion is dominated by the impact of shear stress. For examining the critical position, it must look for the greatest erosion-corrosion occurred at the wall which has the maximum stresses, Fig. 9. The affected part is part 2 and 3 so 2 is the part just after opening the valve, pat 3 has the elbow. The outer parts of the pipe are sensitive to this shear stress because it is the direction of flow according to the position of the valve during the injection of the fluid. The stresses values are important for the opening angle of 15°, similar for angle 30°, 45° and less influencing for the angle 90° of (without obstacle).