Sanacija zavarivanjem prslina sfernog rezervoara za etilen

Abstract

Pressure vessel, spherical, of 3000 m3 working volume, where ethylene is placed, is made of microalloyed steel Nioval 47 - P460NL1 (EN 10028: 3), with wall thickness 18mm and welded on 12 supporting pillars. Regular tests were performed by non-destructive methods (visual, magnetic particle testing, ultrasonic testing) and the indications such as undercuts, group of pores, the lack of weld, craters formed during vessel manufacturing. What is very important but has not been paid enough attention to over the past fifteen years is the visual inspection of the base material of the spherical storage tank, where the indications such as cracks with a total length of over 6000 mm and a depth of 6 to 12 mm (examined by ultrasound) were observed, which were not observed during previous inspection. This paper presents the technological process of repairing of tank using 111 welding process, as well as testing of welded joints after repair. Tank is successfully repaired and tested. Results of this work indicate the need for more detailed testing of base metal in future.