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• Elastic stress and elastoplastic analysis to assess plastic failure were carry out. • A numerical model based on the finite element technique tool was developed. • ASME BPVC Section-VIII, Division-2 code guidelines to conducted the study was used. • Maximum von Mises stress was 200.6 MPa staying below the yield limit of the valve body. • The valve body material safety coefficient was 1.25 MPa. • Screws surpassed the yield limit by 725.72 MPa entering the plastic deformation zone. Assessing the structural integrity of valves is crucial during the development process. Design by analysis involves evaluating unconventional geometries and loads by researching and classifying stresses, then comparing them to allowable values. Although ASME BPVC Section-VIII, Division-2 does not specifically cover valves, key valve design standards reference this code. Hence, this numerical study aims to develop and apply specialized stress analysis models for evaluating plastic collapse and local failure in a rising stem-type gate valve. The methodology is developed to assess the elastic behavior of the valve under stress to evaluate plastic collapse. It is also designed to assess plastic collapse and local failure by considering the material's behavior beyond the elastic range and into the plastic deformation zone. A numerical model using the ANSYS–MECHANICAL tool was developed based on the finite element technique. The main failure modes of a rising stem-type gate valve according to ASME BPVC Section-VIII, Division-2 criteria were considered. The main contribution to valve development is providing specialized stress analysis models and numerical simulations, mainly focusing on the rising stem-type gate valve and aligning it with relevant ASME standards. The results showed that the maximum von Mises stress in the valve body was 200.6 MPa, staying below the yield limit, while the screws surpassed the yield limit with 725.72 MPa, entering the plastic deformation zone. [ABSTRACT FROM AUTHOR]

• The paper investigates the cause of a fracture in a vent line of a main gas process line. • The failure investigation details the methodology , research and analysis used. • The fractographic features observed have been explained. • FEA was used to identify the position of the maximum stress intensity. • It was concluded that the vent line failed due to a fatigue cracking mode. During a routine inspection, the sound of venting gas was heard in the area of the compression module on board a five-year-old natural gas platform in the South China Sea. The sound was traced to a fractured 25 mm vent line pipe on a main process gas line. Analysis of the failure showed that a fracture occurred due to a fatigue failure mode. The fracture was initiated under high stress concentration at the weld toe influenced by a small amount of undercut typically found in such welds. This paper provides a summary of the investigation, methods used, key results and analysis which led to the identification of the root cause of failure. [ABSTRACT FROM AUTHOR]

• The Euler-Lagrangian particle tracking method and the Reynolds stress turbulence model (RSM) were used to simulate the gas-solid two-phase flow of the gate valve system, and the main wall wear of pipeline system was predicted. • The accuracy of this method is verified by flow resistance experiment. • The results show that the existence of groove structure at the bottom of gate valve has an important influence on the distribution of flow field inside gate valve and the wear of main wall in the flow field of pneumatic conveying pipeline. As an important component in industrial pneumatic conveying pipelines, gate valves are seriously affected by gas–solid two-phase flow. Solid matter not only affects the flow resistance characteristics and flow field distribution of the gate valve, but also collides with the gate cavity and the gate plate surface, sliding friction and other effects, leading to serious wear and tear of the internal valve body, resulting in the fall off of the gate valve wall material, affecting the sealing performance of the gate valve, reducing its service life, and affecting the safety and reliability of the pipeline transportation system. Based on the consideration of gas–solid two-phase flow and particle–wall collision, combined with wear prediction model, the flow field, particle trajectory, flow resistance characteristics and wear distribution of main wall in gate valve pipeline system are studied in this paper. The accuracy of this method is verified by flow resistance experiment. The results show that the existence of groove structure at the bottom of gate valve has an important influence on the distribution of flow field inside gate valve and the wear of main wall in the flow field of pneumatic conveying pipeline. At the bottom of the groove, there is a low pressure zone, which makes the gas pressure decrease and increases the cost of pneumatic conveying when the fluid passes through the gate valve; the distribution of velocity and flow field is not uniform, resulting in swirling flow; there are different sizes of swirling flow and secondary flow, resulting in unstable flow; at the groove, particles impact on the groove perpendicular to the flow direction at a larger speed under the action of swirling flow. On the wall, the wear is the most serious here, which reduces the sealing performance of the gate valve. In the groove, the velocity distribution decreases, resulting in the accumulation of triangular particles. [ABSTRACT FROM AUTHOR]