PSI - Issue 31

J. Lukács et al. / Procedia Structural Integrity 31 (2021) 51–57 J. Lukács et al. / Structural Integrity Procedia 00 (2019) 000–000

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their burst tests. The average pressure growth rate values in the first stage of the PS-Bi-2 (i = 1, 2, 3) pipe sections were 0.29-0.36 MPa/s ( 2.9-3.6 bar/s ), nevertheless of the PS-B2-1 pipe section was lower ( 0.15 MPa/s / 1.5 bar/s ) and of the S2-B3-1 pipe section was higher ( 0.51 MPa/s / 5.1 bar/s ). These differences do not cause significant effects on the damage process of the pipe sections and the greatest value cannot considered as dynamic impact. The behavior of the pipe sections during the burst tests were essentially analogical, unfortunately, we have non-return valve closing difficulty in the middle part of the burst test of PS-B2-2 pipe section. Figures 5-7 demonstrate PS-Bi-j (i = 1, 2; j = 1, 2) pipe sections after the fatigue and burst tests.

a)

b)

Fig. 2. Internal pressure vs. time diagrams during the burst tests of the a) PS-Ai-Noj pipe sections (all burst pressure points were indicated); b) PS-Bi-j pipe sections (only one burst pressure point was indicated).

Fig. 3. Unreinforced (WW) pipe section PS-A1-No1 after the first fatigue test.

a)

b)

Fig. 4. Reinforced (W1) pipe section PS-A2- a) No1 after the first burst test, b) No2 after the second burst test.