A unified improved manhole design for a family of 1 - 20 m³ gas pressure vessels: Integration of ASME, TCVN 8366:2010, FEM simulation, and acoustic emission monitoring

This study proposes a unified engineering methodology integrating four components: ASME-based design, verification under TCVN 8366:2010, ANSYS finite element simulation, and acoustic emission monitoring. A 2 m³ gas pressure vessel was selected as the reference model and the methodology was subsequently extended to a family of 13 vessels ranging from 1 to 20 m³, all using the same 405 × 315 mm elliptical manhole. The results show that equivalent stress remains below the allowable stress under both the 16-bar design pressure and the 24-bar hydrostatic test pressure. Acoustic emission results are consistent with ASME-based calculations and ANSYS simulations, with no significant evidence of defect development during pressure testing. The proposed approach provides a basis for structural risk assessment, remaining-life prediction, and future digital-twin development.