Papers by Keyword: Burst Pressure

Abstract: This study addresses the reinforcement of corroded API 5L X42 pipelines using Glass Fiber Reinforced Polymer (GFRP) composite wraps, focusing on optimizing fiber orientation to enhance burst pressure performance. Pipeline corrosion poses significant risks to structural integrity and safety in the oil and gas industry. Experimental burst pressure testing, and Finite Element Method (FEM) were conducted to evaluate unidirectional (0/0/0), bidirectional (0/90/0) and multi-axial (0/45/-45) GFRP wraps. The FEM model, validated against experimental data, showed minimal error with 1.16%. Major findings show that the bidirectional had a maximum stress (501.29 MPa) and burst pressure (44.72 MPa) higher than the unidirectional and multi-axial. Better stress distribution given by the bidirectional structure helped to lower stress concentrations. These results show that pipeline repair techniques can be much improved by orienting fibers correctly. This study found that it helpful in field application of composite repair techniques for corroded subsea pipes.

Abstract: In this work, nitrogen gas inside cooling experiments of CFRP and GFRP wound composite pressure vessels were carried out. Teflon sheet inserted axisymmetric artificial defects in Al-CFRP interface and without any defect composite vessels were manufactured. Thermocouples were positioned at various points on the exterior of the GFRP hoop surface to track the extent of temperature changes during the cooling test. Destructive cutting and optical microscopy were used to observe the post-cooling Al-CFRP interface morphology at defective locations of composite vessel specimens, revealing the propagation of Al-CFRP interface delamination. Furthermore, a comparative analysis was carried out on an additional set of composite vessels under identical cooling conditions, and a burst test was performed to assess the impact of Al-CFRP debonding on the magnitude of burst pressure. Interestingly, the results indicated no significant difference in the burst pressure between vessels with and without the pre-introduced defect post-cooling.

Abstract: The goal of this work was to investigate effect of heating time during welding on mechanical properties of High Performance Polyamide thermoplastic composite material PPAGF40. Studies showed that welded joints with shorter heating time from 6.1 s to 6.7 s had a higher amount of pores and burn mark defects compared to the welded joints with longer heating time. Cross-section analysis of welded samples revealed tendency, that samples with higher heating time from 7.4 s to 11.5 s possessed more homogenous weld seam and higher resistance to burst pressure, respectively from 5.1 bar to 7.5 bar, while the resistance to pressure values of shortest heating time range, respectively are varying from 3.3 bar to 3.9 bar. The weld seam defects like pores and burn marks weakened the welded joint. 470 W of laser power energy input influenced fast melt-down of a cover and a housing, which caused material partial evaporation and later on formation of pores inside weld seam. By using lower 450 W of laser power and scanning speed of 1900 – 1700 mm/s, we can observe more homogenous weld seam. The cross-section of the samples were examined by using optical microscope. Mechanical resistance to pressure was performed in order to evaluate the performance of welded joints of different heating time of PPAGF40.

Abstract: In order to study the pressure carrying capacity of X80 pipe with metal loss defect on the girth weld the water-pressure blasting test of the pipe with metal loss defect was analyzed by experiment and finite element simulation. Based on this, the sensitivity analysis of the factors affecting the pressure carrying of the pipeline, such as the circular size, the axial size, and the depth of the metal loss defect, was carried out. The research results show that the circular size of the metal loss defect on the girth weld had little impact to the pressure carrying capacity of the pipe while it reduced with the increasing of the axial size and the depth of the metal loss defect.

Abstract: The pressure capacity of reinforced thermoplastic pipe was studied by the finite element analysis and experimental study using Φ100 reinforced thermoplastic pipes. The simulation results illustrated that the failure mode of reinforced thermoplastic pipe under internal pressure was the break of glass fiber belt in structural layer. Moreover, the simulated burst pressure fitted well with the experimental result, the small deviation between two results may be resulted from the process defects of RTP.

Abstract: In order to study the pressure carrying capacity of X80 pipe with plain dents, the formation process and the hydraulic test were analyzed by finite element simulation. Based on this, the sensitivity analysis of the factors affecting the pressure carrying capacity of the pipeline, such as the internal pressure, the confinement state and the material performance, is carried out. Research results show that springback amount of the pipeline decreases due to the initial internal pressure, and constraint state has little effect on the pressure carrying capacity while increases with the increasing of the material tensile properties. When the depth of the dent is less than 6% pipe diameter or the strain of the dent is less than 6%, the dent has little impact to the pressure carrying capacity of the pipe.

Abstract: In this paper, the elastoplastic stress analysis of a novel parabola-arc-shaped head subjected to internal pressure has been carried out using finite element method. Limit loads and burst pressures are obtained for various geometric parameters and compared with the conventional torispherical and ellipsoidal heads. For the same middle diameter and thickness, the novel parabola-arc-shaped head shows better mechanical performance than the torispherical head. The burst pressure is mainly determined by the size of cylinder and the burst always occurs in cylinder. The head can improve the burst load when the cylinder is relatively short. The improvement of the novel parabola-arc-shaped head is almost the same as the ellipsoidal head, while the torispherical head is slightly inferior. As the novel parabola-arc-shaped head can be more easily formed with less material consumed compared to the conventional ones, it should thus be applicable in engineering practice.

Abstract: One major concern in maintaining pipeline structural integrity is failure due to corrosion defects. Various tests and codes had been established to assess the corroded pipelines. Burst test is one of the tests being conducted in the lab to assess the integrity of the pipelines. The advancement in computer technology had made the Finite Element Analysis (FEA) capable to simulate the burst test numerically. The objective of this study is to estimate the burst pressure of a corroded pipeline by using FEA. First, Ultrasonic Testing (UT) scan was carried out to establish the corroded pipe profile. FEA was then conducted to simulate the experimental procedure of the actual burst test. Several models were built and simulated by considering the number of defects, their depth and shape as the varying parameter in each simulation. All models were properly constrained and pressurized internally in determining the burst pressure (p_b) of the corroded pipeline. The result obtained by FEA was analyzed and compared to the actual burst test, ASME B31G and DNV-RP-F101 codes. Lastly the best model of FEA was proposed.

Abstract: A brief overview is given in the conventional domed bursting disc structure and manufacturing method. 316L stainless steel as a template is selected. With the investigation on bursting disc material tensile test method, the test results are summarized,also the burst results of disc burst pressure in different sizes. With the help of bursting disc material performance test and bursting disc burst pressure test of 316L , the test results provide a reference for other types of bursting disc.

Abstract: The most important concern in design of filament-wound composite pressure vessels reflects on the determination of the optimum shape and optimum laminate stacking sequence of composite vessels based on the matrix cracking pressure and burst pressure of composite laminates. In this study the Imperialist Competitive Algorithm (ICA) is used to find the optimum laminate stacking sequence of composite vessels that the design considerations are stability and strength constraints. the matrix cracking pressure of filament-wound composite pressure vessels made of different number of helical layers and different layers of Circumferential layers was calculated by using orthotropic material formulae and then, the burst pressure of composite vessels was calculated by using netting analysis. The optimum laminate stacking sequence of filament winding composite was found to maximize the matrix cracking pressure and the burst pressure by using Imperialist Competitive algorithm.