Piping Systems Research Articles

Fungi Associated with Olive Tree (cv. 'Nocellara del Belice') Decay in Trapani Province (Sicily, Italy).

Recently, in several locations in the province of Trapani (Sicily, Italy), olive growers have reported cases of decaying olive trees of cv. 'Nocellara del Belice', showing symptoms of defoliation, branch drying, xylem browning, and reduced production. Internal symptoms include white and brown wood rot, starting from the base of the trunk. These alterations have been observed in trees irrigated using a pipe system at the trunk with spray sprinklers. To identify the causal agents of decay, some trees were eradicated and dissected, and woody samples were processed to isolate and identify the associated fungal micro-organisms. The most common colonies were identified using morphological (macro- and microscopical observation) and molecular (PCR amplification of the rDNA-ITS region) analyses. Nine fungal taxa were identified, of which four were associated with this decay syndrome (Coriolopsis gallica, Fomitiporia mediterranea, Kirschsteiniothelia sp., and Pleurostoma richardsiae), three were considered ubiquitous and opportunistic fungi (Alternaria spp., Aspergillus amstelodami, and Trichoderma sp.), and the other two were mycelia sterilia. Artificial inoculation satisfied Koch's postulates, confirming the pathogenicity of the aforementioned fungi, even though the infections in the fields seem to be related to the irrigation system. This hypothesis would seem to be confirmed by the progression of decay over time in the trees subjected to the irrigation system described but not reported in olive groves differently managed. It is therefore considered appropriate to conduct further and more in-depth investigations aimed at studying the correlation between the irrigation system, presence of fungal agents, and manifestation of the syndrome. A further ongoing investigation is aimed at the use of biostimulants (Agrusaver, Savory Sun, VA LLC) on symptomatic trees, with the aim of both improving the vegetative performance of the host and limiting the symptoms detected in the field.

Facilitating Absorption Spectroscopy of Strongly Absorbing Fluids: A High-Throughput Approach.

Measuring absorption spectra of strongly absorbing solutions is usually only possible by diluting the solution. However, the absorption spectra can be heavily influenced by concentration-dependent interactions, so dilution leads to misleading results. To enable reliable absorption measurements of concentrated solutions, we introduce in this work thinning fluid film spectroscopy (TFFS), a simple and highly automatable method. We present three exemplary measurement modes of TFFS suitable for many different applications and validate the TFFS measurements with control data obtained in specialized, low optical path length cuvettes. Additionally, we compare the suitability of the different measurement modes over a broad concentration range and demonstrate the automation possibilities with a spectroscopy robot. Beyond this automated approach for highly efficient and high-throughput lab work, we also show the possibility of direct integration into production systems with an in-line setup, which can be incorporated into a variety of pipe systems. The TFFS method is not limited to samples from material science but can be transferred to a broad variety of research and industry fields, including proteins, food, and pharmaceuticals or also agriculture and forensics.

Acceleration is the key to drag reduction in turbulent flow

A turbulent pipe flow experiment was conducted where the surface of the pipe was oscillated azimuthally over a wide range of frequencies, amplitudes, and Reynolds numbers. The drag was reduced by as much as 35%. Past work has suggested that the drag reduction scales with the velocity amplitude of the motion, its period, and/or the Reynolds number. Here, we find that the key parameter is the acceleration, which greatly simplifies the complexity of the phenomenon. This result is shown to apply to channel flows with spanwise surface oscillation as well. This insight opens potential avenues for reducing fuel consumption by large vehicles and for reducing energy costs in large piping systems.

Quality Determination of Dairy Farm Wastewater in Dinajpur

At present environmental pollution is a talked about issue. Due to environmental pollution, humans and animals face threats. The scientist has pointed out that waste is one reason for climate change. Solid, liquid, gaseous etc. are different types of waste. The experiments were conducted to determine the chemical constituents present in dairy farm wastewater, wastewater management practice and environmental impact and compare it with the groundwater Dinajpur Sadar upazila. The data concerning the dairy farm wastewater in Dinajpur was obtained through a designed questionnaire, and separate area inspection interacting with the proprietor and workers in the dairy farm. Randomly collected samples from different dairy farms. The chemical constituents of the wastewater sample were determined by a laboratory experiment. The wastewater contained Mg, Na, Ca, Cl-, K, EC, P, HCO3-, pH, TDS, DO, COD, Zn, S, BOD, HT and NO3-. The Na, K, Ca and pH concentration of wastewater under the range in groundwater in Dinajpur. However, concentrations of P, TDS, Mg, EC, Cl-, HCO3- and HT are above the groundwater range in Dinajpur. The produced wastewater was disposed of either through drainage or piping systems on fellow land, ponds, open lakes, roadside land, urban drains, and rivers. The unplanned wastewater disposal creates bad odor, and environmental pollution, seduces the growth of mosquitoes decreases the water quality, soil quality and health hazards. Therefore, it can be concluded that the prevailing dairy farm wastewater disposal system not being satisfactory. The proper disposal system should be improved to reduce environmental impacts.

Enhanced elastic stress solutions for junctions in various pipe bends under internal pressure and combined loading ([formula omitted] pipe bend, U-bend, double-bend pipe)

Piping systems in nuclear power plants normally operate under high pressure and high temperature. To efficiently manage space within these systems, pipe bends are extensively used. However, the welded joints connecting these pipes may be susceptible to flaws due to weld residual stress, transient loads, and operating environments. When flaws are present in such areas, analytical evaluation of flaws is to be carried out based on fracture mechanics parameters such as stress intensity factor. To calculate the stress intensity factor, distributions of the elastic stress are required. Therefore, this paper presents closed-form approximations of elastic stress in the junction between a pipe bend and a straight pipe under internal pressure. Review of the existing elastic stress solutions for estimating the stresses in pipe bends was carried out analyzing their limitations. Based on those limitations elastic stress solutions for thick to thin wall pipe bends were proposed and were validated against finite element (FE) analysis for thick-wall to thin-wall pipe bends under internal pressure and combined loading (i.e. internal pressure, in-plane bending, out-of-plane bending inflicted simultaneously). 90° pipe bend, U-bend and double-bend pipe configurations were considered and showed good agreement with the FE results exhibiting less than 5.8 % discrepancies. The accuracy of the elastic stress solutions for pipe bends provided in the existing code are summarized and validated in the appendix as well.

Best clinical practice experience at University of Gondar Comprehensive specialized Hospital Emergency and critical care Medicine department, A Case Study Under a resource limited set up

Abstract Background The emergency department (ED) is unique unstable environment where someone faces unscheduled and undifferentiated diseased patients, stressed families, unsettled staffs and unequitable resources.UoGCSH is the oldest in the Ethiopia and the only referral hospital for more than 13 million people from the five-zone north-west Ethiopia with 950 beds capacity. During the 2020 G.C a proposal paper was submitted to the administration bodies of the college and the hospital. The proposal was suggesting short term, mid-term and long-term quality improvement segments implemented in institutionally convenient manner. Objective To describe the transformation of emergency and critical care medical services at University of Gondar Comprehensive specialized hospital from scratch to the current status. Method A descriptive case study design was applied to narrate critical care service transformation at UoG Comprehensive Specialized Hospital. Since this case study is a data review from gathered secondary data, desk reviews of the emergency department, quality directorate data review, and the annual audit report review, there was no need for IRB approval. Result and recommendation After a year of renovation, we were able to organize a newly refurbished emergency room having a triage area with adequate reception space, Red resuscitation area with 10 beds (considering patient overflow), Orange with 18 beds, Yellow with 10 beds and floater area, isolation room, decontamination room, ED laboratory, main store, disaster store and piped oxygen system to all beds. we have gone a long journey in bringing those promised practices into demonstrable practice and finally replicable prototypic best practice. Even though we paced extra miles in achieving this status. Standard emergency room work flow implementation enable us to control the day-to-day patient and attendant crowding that impedes the anticipated medical treatment outcome and result in a significant dissatisfaction.Despite this achievement the trauma center establishment and high-quality patient care is recommended.

A Novel Ultrasonic Leak Detection System in Nuclear Power Plants Using Rigid Guide Tubes with FCOG and SNR.

Leak detection in nuclear reactor coolant systems is crucial for maintaining the safety and operational integrity of nuclear power plants. Traditional leak detection methods, such as acoustic emission sensors and spectroscopy, face challenges in sensitivity, response time, and accurate leak localization, particularly in complex piping systems. In this study, we propose a novel leak detection approach that incorporates a rigid guide tube into the insulation layer surrounding reactor coolant pipes and combines this with an advanced detection criterion based on Frequency Center of Gravity shifts and Signal-to-Noise Ratio analysis. This dual-method strategy significantly improves the sensitivity and accuracy of leak detection by providing a stable transmission path for ultrasonic signals and enabling robust signal analysis. The rigid guide tube-based system, along with the integrated criteria, addresses several limitations of existing technologies, including the detection of minor leaks and the complexity of installation and maintenance. By enhancing the early detection of leaks and enabling precise localization, this approach contributes to increased reactor safety, reduced downtime, and lower operational costs. Experimental evaluations demonstrate the system's effectiveness, focusing on its potential as a valuable addition to the current array of nuclear power plant maintenance technologies. Future research will focus on optimizing key parameters, such as the threshold frequency shift (Δf) and the number of randomly selected frequencies (N), using machine learning techniques to further enhance the system's accuracy and reliability in various reactor environments.

A numerical assessment of different geometries for reducing elbow erosion during pneumatic conveying

This paper investigates wear characteristics in a dilute phase pneumatic conveying pipe system using a Euler-Lagrange method. Simulations couple computational fluid dynamics (CFD) with the discrete element method (DEM) to analyze three different bend geometries, including two erosion-reducing designs and a standard bend, all with an effective bend radius to pipe diameter ratio (R/D) of 1.5. SiO2 particles, 1 mm in diameter, are conveyed at gas velocities of 15 to 30 m/s and mass loadings of 1 to 4 kgparticle/kggas. The CFD-DEM predictions were validated against experimental data, showing good agreement in erosion distribution. The study evaluates erosion rates, pressure drops, and particle stressing for the three bends. Results suggest that certain bend designs significantly reduce erosion while slightly increasing pressure drop, although reduced particle-wall erosion may increase the overall particle stressing. The obtained results provide guidance on selecting an appropriate bend design and for potential geometry optimizations.

Microstructure evolution and deformation mechanisms of service-exposed P91 steel via interrupted uniaxial creep tests at 660 °C

Creep degradation behaviour of service-exposed P91 steel is evaluated during interrupted creep tests at 660 °C and 80 MPa using a number of material characterization techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), energy dispersive spectroscopy (EDS) and optical microscopy (OM) to identify the microstructural evolution and the associated deformation mechanisms. Microhardness has also been measured in order to evaluate the softening mechanism. Under the creep conditions examined, microstructural degradation is found to be governed by the disappearance of the lath sub-structure, lath widening and recrystallization, as well as dislocation density reduction, coarsening of M23C6 and creep cavitation while MX and Laves phases are stable. Hardness evolution, extrapolated from hardness data obtained from uniaxial creep tests, is used to characterize the softening of the material. On this basis, hardness decrease is justified in term of the aforementioned microstructural changes. Implications of the findings for specific in-service life management in thermal plant piping systems are addressed.

Research on digital vibration model of typical components in pipe system

The spatial distribution of pipe system is complex, long span and multi-point elastic support, so vibration analysis of pipe system is required in the pipeline design. This paper takes the pipe system as a typical component, based on the Timoshenko beam model, establishes a dynamic procedure for straight pipe elements that considers the axial flow rate of fluid, the pressure on the pipe wall, the Poisson coupling effect of fluid and pipeline structure, and the axial, transverse and torsional vibration. Through Laplace transform, the frequency simplified dynamic model is established. And the frequency transfer matrix model of straight pipe elements and the boundary constraint matrix of common boundary (such as fixed support) is established. Finally, the frequency domain transfer matrix model of different pipeline elements are set to the overall transfer matrix of the flow pipe system, providing a convenient means for rapid optimization of pipe system vibration.

Vibration analysis of piping system coupled with conical-cylindrical combined shells

Fluid-filled piping system are widely used in power cooling, fuel transportation and underwater vessel, which not only produce vibration along the system, but also transmit to the connecting structure to generate noise in ambient environment. Most investigations have concentrated on either the vibration characteristics of piping systems or of combined shells separately. In this work, an analytical impedance synthesis method (ISM) is proposed to analyze the vibration characteristics of a pipe-hull coupled system, in which the hull can be simplified to a combined conical-stiffened cylindrical-hemisphere shell. The piping system is modeled by fluid-filled beams in three-dimensional configuration. Wave function and power series solution are used to describe the displacements of cylindrical and conical shell respectively. Based on exact analytical solutions, the impedance matrix of each segment is established separately and assembled in the global coordinate by displacement continuity and force balance boundary conditions. Forced responses are compared with the experimental results to verify the correctness of the method.

Dynamic analysis of whipping behavior induced by the circumferential fracture of high energy pipes considering fluid-structure interaction effect

To analyze the dynamic characteristics of whipping behavior induced by the circumferential fracture of high energy pipes, a numerical model of the piping system was presented based on the bidirectional fluid-structure interaction method. The reliability of this model was validated against experimental results. Furthermore, the dynamic characteristics of whipping behavior were studied, as well as the effects of some main parameters. The numerical results suggest that the entire whipping behavior can be divided into four stages: free-whipping stage Ⅰ, free-whipping stage Ⅱ, collision stage and periodic stage. The dynamic response of whipping behavior is different in the four stages and is dominated by a single mode with a frequency of 29.35 Hz under the combined action of the thrust force and U-bolt restraints. The increase of inlet flow rate causes the enhancement of thrust force and thus makes its dynamic response more complicated. The parameter analysis shows that the whipping behavior can be suppressed by choosing the small initial clearance, setting the suitable gap and increasing the straight segment length of U-bolt restraints. The above results are helpful to understand the dynamic characteristics of whipping behavior and provide valuable suggestions for the optimization of the protection measures.

Insertion loss of pipe clamps: Quantity for prediction or manufacturer's advertising?

The noise emitted by water conveying pipes as part of sanitary installations is, in most cases, dominated by structure-borne sound transmission. The water flowing through the pipe causes a vibration of the pipe system that is transmitted to the installation wall through pipe clamps. A common mitigation measure is an elastic inlay inside the pipe clamps. Some manufacturers of these clamps advertise the insertion losses determined by non-standardized tests. Recent studies show a high dependency of the insertion loss on the mounting conditions, e.g. how tight are pipes fastened in the clamp. This contribution aims to answer the question of whether and how the mounting condition affects the insertion loss of the pipe clamps and thus how representative the specified values can be for the building situation. The investigations are carried out in-situ on the reception plate and in a building like test stand with an excitation by flowing water as well as with impact hammer excitation. This study is part of a research project with the overall aim to provide source data for the prediction of the sound transmission in buildings using EN 12354-5.

Effect of internal pressure on the flexural fatigue behaviour of trenchless internal replacement pipe systems

Internal replacement pipe (IRP) systems are a novel trenchless technique that is gaining interest in the rehabilitation of damaged legacy pipelines distributing natural gas. Performance evaluation of IRP systems under repetitive loads transmitted from vehicular traffic is essential to ensure their optimal and safe design. This study conducted numerical simulations to examine the impact of internal pressure on the bending fatigue behaviour of IRP systems that are fully bonded to legacy gas pipes with circumferential discontinuities. Other design parameters include the thickness and modulus of elasticity of IRP and the level of transmitted traffic load. The findings indicate that the operating internal pressure has a greater impact on the longitudinal stresses than the circumferential stresses of IRP when subjected to cyclic bending. The level of internal pressure changes the failure behaviour of IRP under fatigue. Based on the results obtained from extensive parametric simulations, mathematical expressions were formulated to predict the fatigue life of the IRP systems. Contour plots were generated to represent fatigue life response for different combinations of internal pressure levels and transmitted traffic loads.

Quantifying the tangential oscillation of thermal stratification by using principal component analysis

Tangential oscillation of thermal stratification is a new finding in previous investigations on thermal-mixing process at pipeline T-junctions. This phenomenon can create regular temperature changes on the pipeline inner surface and lead to material damage caused by the degradation mechanism of thermal fatigue, which has been frequently reported as a reason for incidents in piping systems of nuclear power plants. Previous investigations cannot provide a quantitative description of this phenomenon, making it difficult to understand or evaluate the fatigue potential due to this phenomenon. In this study, a new method namely principal component analysis has been employed for quantitatively estimating the angular shift of the thermal stratification in pipe tangential direction. Time-dependent angular shift is extracted from the temperature data of the transient simulations of the pipe flow and confirms the initiation of the tangential oscillation of thermal stratification. Moreover, a characteristic frequency of approximately 2.3 Hz has been identified from the frequency spectrum of the time-dependent angular shift. It indicates a potential risk in the piping material due to thermal fatigue. Furthermore, results of this study show a high efficiency and accuracy of the principal component analysis method in quantifying tangential oscillation. It can be applied in further investigations of similar phenomena of thermal stratification.

Comparative study of flame propagation characteristics of methane explosion in pipeline with different venting structures at different ignition positions

The effect of central ignition and four types of explosion vents (circular vents with areas of 22.89, 15.20, and 9.07 cm2 and a cross-shaped vent with an area of 15.20 cm2) on the flame propagation of methane explosions was investigated by using a rectangular blast pipe system and analyzed in comparison with the closed-end ignition condition. Central ignition shows that the flame propagation velocity on both sides of the pipe increases and decreases. The peak pressure decreases as the vent area increases. Specifically, Pm (9.07 cm2) > Pm (15.20 cm2) > Pm (22.89 cm2). The flame temperature at the closed end was consistently higher than that at the vented end. The vm values in the closed-end ignition pipe increased by 20.0 %, 41.8 %, 45.8 %, 40.9 %, 31.5 %, and 19.0 %, respectively, over the central ignition position when the methane concentration was 8–13 %. When the methane concentration deviates from the stoichiometric ratio, the difference in peak pressure between closed-end and central ignition can be up to 0.15 MPa, which is 26.7 % of that of central ignition. The peak temperatures observed at points 1–2 in the closed-end ignition were consistently higher than the central ignition.

Defect characterization from magnetic field leakage signals in petroleum and natural gas pipelines

Pipelines transport invaluable energy resources such as crude oil and natural gas over long distances. The integrity of the piping system in terms of safety of the process is then of high importance. However, pipes are prone by time to defects that may degrade their properties and lead to failures. In this paper, we study the effect of defect parameters on the magnetic field leakage captured by Hall sensors operating along the pipe. In fact, the obtained results show that the defect parameters influence directly the MFL amplitude and shape. For this reason, the inversion problem allowing us to reconstruct the defect from the MFL signals became fast and easier in comparison to the deterministic and probabilistic algorithm inversion procedure. However, the simplified system cannot describe the real defects and the three-dimensional numerical study became necessary. In tank floor inspection domain, as our recent published work, we have studied the performance of defect shape reconstruction from MFL array sensor imaging and depth estimation while using an iterative inversion method. Indeed, the first stage consists of determining the defect width and length from magnetic flux leakage mapping reconstructed from the recorded signals of the micro-integrated magnetic sensors. Then, after coupling Comsol and Matlab software, the defect depth is obtained by coupling the 3D finite elements method and a fast iterative algorithm recently developed. Consequently, the defect shape and size are obtained after a few iterations with high precision. Furthermore, this method of defect reconstruction and seizing can be extended for irregular defect shapes encountered in pipeline such as cracks and corrosion.

Investigation of Surge Phenomena in a Centrifugal Compressor by 3D-1D Coupling Approach

Abstract Critical instability, such as surge phenomena, can occur at low flow rates for a compressor system, leading to flow rate fluctuations and potential damage. To study this, traditional numerical analysis requires a comprehensive approach encompassing the compressor and its piping system. This demands extensive computational resources and time due to the complexity of capturing internal flow during surge, including separation and vortex generation. To overcome these limitations, this research proposes a computational strategy combining 3D and 1D analysis for enhanced efficiency and reduced computational demands, which employs 1D analysis for more straightforward flow regions like piping and 3D analysis for the more complex compressor section. This approach is facilitated using AMESim for 1D and STAR-CCM+ for 3D simulations, enabling seamless integration and data exchange between different dimensional analyses. The method improves computational efficiency and reasonably approximates surge phenomena compared to experimental data. The 3D and 1D coupled analysis closely aligns with experimental data, providing a viable and more effective alternative method for surge analysis in compressor systems. This methodology promises to streamline the study of compressor surge phenomena, providing a practical tool for engineers and researchers.

Research and Application of Intelligent Well Completion Technology in Offshore Oilfield

Abstract The reservoirs in Bohai oilfield were mainly composed of unconsolidated sandstone. A single multi-layer gravel packing operation could greatly reduce the packing operation time and improve the operation efficiency. However, the conventional tools were limited by the double-layer central tube structure, which resulted in large packing friction and high pressure consumption due to its small annular area, which limited the limit operation length and displacement. In order to solve this problem, we independently developed a double-layer screen tube one-time multi-layer fracturing packing tool, innovatively set up production interlayer in the screen pipe, formed a bypass diversion screen pipe system, so as to reduce the downward entry of one layer of central pipe during filling, simplify the structure of the filling string, and greatly reduce the friction of the string. The results showed that the limit packing length and displacement were 1200m and 45bpm respectively, which were 300% and 50% higher than the traditional packing tools, and the operation range of the tools was improved. The safety and efficiency of double screen fracturing and filling operation were ensured by innovating the quick connection method of double screen pipe, fast pressure test tool and expanding switch tool of oil pipe. The application in well LX has realized the purpose of sand control by five layers filling in one time. The packing length was more than 400 m. Combined with the problems in field operation, it had been applied in 5 areas The improvement suggestions of the tool are put forward. The double screen pipe one-time multi-layer fracturing packing tool and its supporting technology realized the ideal packing parameter requirements of low pump pressure and high return velocity. It could be widely used in sand control operation of multi-layer gravel packing fracturing in large-span perforation section in the future, which greatly improved the operation efficiency and has good economic benefits and promotion value.

Attenuation properties of a meta-pipe: Analytical, experimental, and numerical prediction

Flexural vibration characteristics of a meta-pipe are investigated in this paper. Initially, the metamaterial piping system consisting of a homogeneous pipe and periodic flexible supports is designed. Subsequently, the dispersion relationship which is a function of the wavenumber and the frequency is derived employing the transfer matrix method and Bloch’s theorem. The designed system reveals a zero-frequency stopband and a wide passband in the examined frequency range, which are verified by both experimental and numerical results. To enhance the performance of this system, it is essential to effectively control the obtained passband. For this, a single-degree-of-freedom localized resonator is designed, which is subsequently installed at the center of each unit-cell of the pipe. The dispersion properties of this system are first evaluated analytically and then validated using experimental and numerical methods. Finally, the effect of pipe system parameters and resonator properties on the stopband characteristics is studied in depth. It was observed that the stopband properties can be effectively tuned by appropriately designing the piping system and resonators. The results presented in this study offer valuable insights into the propagation characteristics of flexural waves and the strategies devised for controlling vibrations in pipes.