Piping Systems Research Articles

Numerical and Experimental Validation of a New Methodology for the Design of Michel-Banki Turbine

Michell-Banki cross-flow turbines (MBT) are low-cost turbines that are easy to manufacture and maintain, which makes them ideal for implementation in small-scale hydroelectric projects. Although the MBT has lower efficiencies than turbines such as the Pelton and Francis, it maintains its efficiency stable in the face of fluctuations in flow conditions. The objective of this study is to validate, both numerically and experimentally, a new design methodology that allows the construction of an MBT based on site conditions. For this purpose, the design of the different components of an MBT was implemented according to the site conditions. The experimentation was carried out in a hydraulic test bench, which consists of a water tank, a centrifugal pump, a piping system, a PMAG SGM LEKTRA magnetic flow meter, a TRS605 FUTEK torque sensor, a pressure gauge, and a model of MBT designed and manufactured from scratch. It was concluded that the proposed methodology allows for obtaining experimental and numerical efficiencies of and, respectively. Thus, a numerical-experimental validation of the MBT design and manufacturing methodology could be carried out.

Experimental study on the dynamic response of the non-structural piping system by altering the position of diagonal braces

Damages to nonstructural components (NSCs) are frequently reported after earthquakes. Suspended piping systems are significant NSCs that play an important role in the functionality of civil infrastructures. However, during seismic events, the piping systems undergo large displacement and collide with each other and the structural components, hence the piping systems may fail and suspend the functionality of facilities. In this study, an experimental program was conducted on the multi-layered piping system with transversal and longitudinal diagonal anti-seismic braces mounted at different positions to increase the overall lateral stiffness and reduce displacement of the piping system. During the experimental program, specimens were subjected to quasi-static cyclic loading based on the loading protocols suggested by the current Chinese code CJ/T 476–2015. Experimental data was used to obtain hysteresis, and strain curves to find an optimal position for mounting diagonal braces on the piping system. It can be concluded that for multi-layered piping systems when the diagonal braces are mounted at the position or near the center of inertia of the piping system, diagonal braces contribute the most to mitigate lateral dynamic loads.

Stability performance of pumped-storage units considering elastic water hammer effects in pressurized piping systems: Mechanism analysis and quantitative criterion

The flow characteristics of water columns in pressurized piping systems significantly influence the stability of pumped-storage power stations (PSPSs). However, the complex mathematical representation of the elastic water column often leads to its simplification to a rigid column in stability analyses. This study established elastic and rigid models of a PSPS system based on elastic and rigid water columns, respectively. The stability regions of the governor parameters for these two models were determined and compared. Results indicate that the stability region of the elastic model is smaller than that of the rigid model. Consequently, using a simplified rigid model to evaluate the stability of an actual elastic system would pose potential instability risks. Furthermore, the primary cause of the stability difference between the elastic and rigid models is identified as the water hammer wave velocity. As the wave velocity increases, the stability region of the elastic model expands, eventually approaching that of the rigid model. Lastly, the coupling mechanism between the pressurized pipe and the pumped-storage unit is clarified. The modulus of the water hammer reflection coefficient is proposed to quantify the stability performance of the pumped-storage unit. These findings provide crucial insights for ensuring the stable operation of PSPSs.

Nonlinear Oxidation Behavior at Interfaces in Coated Steam Dual-Pipe with Initial Waviness and Cooling Temperature

A numerical simulation method is proposed to investigate the nonlinear growth of thermally grown oxide (TGO) on a novel coated steam dual-pipe system operating at 700 °C. Utilizing oxidation kinetics data from high-temperature water vapor experiments, the study examines interface stresses and morphology evolution, considering initial surface waviness and cooling temperature effects. The findings indicate that the parabolic law accurately describes the nonlinear growth of TGO during high-temperature water vapor oxidation, with the TGO growth oxidation rate constant being 4.5×10−4μm2/h. The growth rate of TGO thickness decreases with increasing oxidation duration. Stress concentrations are found to develop at TGO interfaces, particularly in regions with high curvature, and those with elevated wavy amplitudes. The primary factor influencing stress redistribution and morphology evolution is the wavy amplitude of the TGO. Additionally, variations in cooling temperature affect interface stresses along the axial direction of the pipe system during nonlinear oxidation, resulting in relatively minor changes in morphology.

Experimental study on stability and heat transfer characteristics of separated heat pipe with a compressible volume condenser

A novel Separated Heat Pipe (SHP) system incorporating two magnetic spheres (SHPMS) was proposed for power generation (US Patent 11365653B2, 2022) using low-grade thermal energy, or offering both reliable emergency power and efficient heat transfer for spent fuel pools. This paper reports the experimental investigation on flow and heat transfer characteristics of the SHP, providing a foundation for the R&D of SHPMS. The SHP system features a unique shell-and-tube condenser structure, where the tube side serves as the cooling coil, while the shell side functions as the condenser chamber, with the dual roles of liquid storage and surge tank. The study researched the stability and heat transfer performance of the SHP under various parameters, including filling ratios ranging from 17 % to 98 %, cooling temperatures between 14 °C and 22 °C, and system pressures from 630 to 830 kPa. Analysis of instantaneous temperature, pressure, and flow patterns reveals the absence of high-frequency oscillations or alternating flow patterns, indicating that the condenser's condensing chamber may eliminate the instability in the SHP. Comparative analysis of the heat transfer coefficient and thermal resistance indicates that higher filling ratios and system pressures impair heat transfer performance, with optimal results at lower filling ratios (17 %–55 %) and pressure (630 kPa), where the higher heat transfer coefficient and lower thermal resistance were observed. Cooling temperatures showed little impact on heat transfer, allowing it to be chosen based on safety and energy efficiency needs. This study provides a new perspective on SHP systems with compressible volume condenser, offering a potential solution to address the instability challenges of SHP and the selection of operation parameters.

Manajeman Pendidikan Karakter dalam Membina Akhlak Siswa: Studi Kasus di MA Al Zaytun Indramayu

This study examines character education management at MA Al-Zaytun Indramayu, recognized as a pioneer of character education in Indonesia since 1999. Using a qualitative descriptive approach, this research explores four management aspects: planning, organizing, implementation, and supervision. The findings reveal that character education planning at MA Al-Zaytun was formulated by a dedicated team led by AS Panji Gumilang and realized through a modern boarding school system with a “one pipe system” approach. Organizing involves the Indonesian Pesantren Foundation (YPI), the Board of Teachers, and all teaching staff, utilizing modern education management principles. Implementation is conducted comprehensively through formal, non-formal, and informal channels, such as the study of Statecraft and Human Rights (KHAM) and extracurricular activities. Supervision is systematically carried out through observation, direct inspections, and regular discussions, led by AS Panji Gumilang. This study highlights the critical role of management in the successful implementation of character education based on values of peace and tolerance.

Mesh Sensitivity Analysis of Axisymmetric Models for Smooth–Turbulent Transient Flows

The current paper focuses on the assessment of radial mesh influence on the description of the transient event obtained by an axisymmetric model. The objective is to reduce computational effort while accurately calculating hydraulic transients in smooth–turbulent pressurized pipes. The analyzed pipe system has a reservoir–pipe–valve configuration with an inner diameter of 0.02 m and a total length of 14.96 m, with the initial discharge being equal to 120 × 10−3 L/s (Re = 7638). An extensive study is carried out with 80 geometric sequence meshes by varying the total number of cylinders, the geometric common ratio, and the pipe axial discretization. The benefit of increasing the geometric common ratio is highlighted. A detailed comparison between two meshes is presented, in which the best mesh (i.e., the one with the lowest computational effort) has a three-fold higher value of the geometric common ratio. The two meshes show small differences for the instantaneous valve closure, limited to a time interval immediately after the arrival of the pressure surge and only during the first pressure wave. The dynamic characterization of the transient phenomenon demonstrates the in-depth consistency between the model results and the hydraulic transients’ phenomenon in terms of the piezometric head, the wall shear stress, and the mean velocity time-history, in comparison to the results obtained with the shear stress, lateral velocity, and axial velocity profiles.

Hydrogen and odorized methane blends under variable Reynolds number conditions with and without leaks

Customer-side piping systems involve low Reynolds number flows with prolonged periods under no-flow conditions. In this research, odorized CH4 (methane)/H2 and N2 (nitrogen)/He (helium) blends are investigated experimentally at variable Reynolds number (0 < Red < 5200) to determine if component separation occurs and if the presence of H2 suppresses odorant performance. After prolonged periods under no-flow conditions, all investigated mixtures exhibit varying degrees of component separation. Leak events of odorized CH4/H2 are examined using gas sample analysis. After accounting for gas dilution, leaks of odorized CH4/H2 under no-flow conditions exhibit odorant fade of Tert-Butyl Mercaptan while Methyl Ethyl Sulfide concentrations remain constant. Although odorant fade of Tert-Butyl Mercaptan occurs, measured levels are still approximately 50 times above levels at which the human olfactory sense can either detect or characterize the odorant. For both odorants, suppression due to the presence of H2 is not observed.

Assessing the Critical Factors Leading to the Failure of the Industrial Pressure Relief Valve Through a Hybrid MCDM-FMEA Approach

Industrial pressure relief valves must function reliably and effectively to protect pressurized systems from excessive pressure conditions. These valves are essential safety devices that act as cushions to protect piping systems, equipment, and vessels from the risks of high pressure, which can cause damage or even explosions. The objectives of this study were to minimize valve failures, decrease the number of rejected valves in the production line, and enhance the overall quality of pressure relief valves. This work introduces an integrated quality improvement methodology known as the hybrid multi-criteria decision-making (MCDM)—failure mode and effects analysis (FMEA) approach. This approach is based on prioritizing crucial factors for any failure modes in the industrial setting. The presented case study demonstrates the application of a hybrid approach for identifying the fundamental causes of industrial pressure relief valve failure modes and malfunctions. This investigation highlights the applicability of FMEA as a methodology for determining causes and executing remedial actions to keep failures from happening again. FMEA helps uncover the underlying causes of industrial pressure relief valve failures, while the integration of the hybrid MCDM methodology enables the application of four integrated MCDM methods to identify crucial factors. The adopted model addresses the shortcomings of the conventional FMEA by accurately analyzing the relationships between the risk factors and by utilizing several MCDM methods to rank failure modes. Following the application of the adopted methodology, it was discovered that the high-risk failure modes for the pressure relief valve included misalignment of wire, normal wear/aging, rejection of machined parts, mismatch of mating parts, and corrosion. Therefore, risk managers should prioritize developing improvement strategies for these five failure modes. Similarly, failures comprising debris, delayed valve opening, internal leakage, premature valve opening, and burr foreign particles were determined as second essential groups for improvement.

Flow characteristics analysis and application research of multi-branch piping

Abstract This study examines the flow characteristics of multi-branch piping and provides production guidance for tobacco-specific ventilation rate standard rods (VRSRs), focusing on VRSRs within a multi-branch pipeline structure as the research subject. The present work analyses the flow resistance, and flow distribution on the influence of each piping section volume flow. By adopting the iterative method to appropriately construct the mathematical model of the VRSR, an effective technique is developed for thoroughly examining specific VRSRs. The performance of these customized VRSRs is then methodically assessed through repeatability and stability tests, and their suitability is further analyzed by employing five types of ventilation rate test equipment. The main findings reveal: (1) Customized VRSRs exhibit high repeatability and stability; (2) Customized VRSRs are compatible with five common types of ventilation rate testing equipment. Consequently, the model offers scientific theoretical guidance for the production of tobacco-specific VRSRs. Additionally, the study serves as a practical case reference for the production of multi-branch piping systems.

Investigation of Debonding Effect in Internal Replacement Pipe System Under Lateral Loading

Investigation of Debonding Effect in Internal Replacement Pipe System Under Lateral Loading

Fusarium spp. in Metalworking Fluid Systems: Companions Forever.

Water-miscible metalworking fluids (MWFs) are utilized in a variety of metal removal and forming operations. For end-use, formulation concentrates are diluted in water, creating conditions conducive to microbial growth and metabolism, possibly compromising the fluid's integrity and mechanically obstructing filters or piping systems. Metalworking machines offer additional habitats on surfaces that are in permanent or temporary contact with MWFs. For that reason, biocides have been incorporated into concentrates for years, but legal constraints will restrain their use in the future. While bacterial contamination of MWFs is well documented, fungal contamination is often overseen and infrequently reported in the literature. In this study, we report fungal prevalence in in-use MWFs sampled worldwide over 10 years, and we are convinced that the presence of fungi is the norm rather than the exception. In addition, we evaluated the inhibitory effect of fungicides on fungal growth, sporulation and spore viability using traditional culture-dependent methods and flow cytometry. In essence, we show that the effectiveness of these fungicides is limited and dependent on the chemical construction of the fluid. We think that the ecology created by water-diluted MWFs is of higher importance than the anti-fungal activity of single components.

An Experimental Investigation of the Effect of Two-Phase Flow in a Manifold on Water Jet Lengths

The outlet flow rates and changes in behaviors of five outlet ports where water and air–water (two-phase) mixtures pass horizontally in a manifold pipe system were investigated experimentally. The effects of different air-flow rates, vacuumed from the atmosphere with a Venturi device in the system, on the outlet flow rates and diameters of the manifold port outlets were compared by measuring the outlet jet lengths. The system performance provided homogeneity of manifold port outlet flows and was tested. As a result, it was observed that homogeneous jet lengths were obtained in both single and two-phase low main manifold flows and equal outlet port diameters. When the main manifold flow rate V is 1.5–2 m/s, the system is stable and produces high jet lengths. The manifold pipe systems used in the experimental setup provide suitable working conditions for d/D = 0.433. The system does not show a smooth flow pattern with Venturi devices for d/D &lt; 0.433. The low flow rates in this study’s tests are key. They are vital for designing micro irrigation systems. This depends on the critical d/D ratio of the system.

Optimization of cooling system parameters with temperature field of mass concrete during hydration

Embedded cooling pipe system is regarded as the primary means in mass concrete to control the temperature. The effects of three factors are investigated on the thermal field of mass concrete by the combination of measurement, theoretical analyze and numerical simulation in this paper, including cooling pipe spacing, pipe diameter and pipe arrangement. The results demonstrate that the peak temperature is reduced by the increase in both of the pipe distance and pipe diameter. The peak temperature is measured to decrease from 1 °C to 3 °C on the monitoring points, with additional 0.5 m of pipe spacing or 10 mm of pipe diameter. The serious influence is conducted by the pipe diameter on the temperature difference, and the selection of cooling pipe diameter is considered to balance multiple problems in the project necessarily. The serpentine arrangement is more widely used for better cooling and construction in the comparison of the circular arrangement. The results on the optimization of cooling system are utilized for the project to control the hydration heat accurately and reduce or even prevent the generation of cracks.

Properties of polyurethane foam/natural fibre composite for air conditioning insulation

ABSTRACT This study focuses on the fabrication of a biocomposite with insulating properties suitable for application in refrigeration pipe systems. The objective of this study was to utilise coconut husk and rice husk in a 1:1 ratio as reinforcement for flexible polyurethane foam. Biocomposites were made using hand mixing and casting technique reinforcement ratios of 5%, 10%, 15%, 20%, and 25% weight ratios from reinforcement husks. A thermal resistivity test, along with tensile test and water absorption measurements as a function of fibre content, was conducted according to ASTM standards. The study demonstrated that incorporating coconut and rice husks as reinforcement in polyurethane foam significantly improved the tensile properties of the composite material. The composite reinforced with 25% weight has been found to have highest tensile stress. In contrast, the thermal resistivity is observed to decrease as the fibre content is increased. A maximum thermal resistivity at 5% wt was found from the reinforcement. On the other hand, the amount of water absorption of the polymer compound increases with the increase in weight percentage of natural fibres. Based on these results, Flexible polyurethane foam reinforced with coconut husks and rice husks shows a promising solution for use as insulation for air conditioning pipes.

A study on the reduction of high-temperature in the high-pressure piping system of civil aircraft

Abstract For the study of the bleed air flow process in high-pressure pipelines, theoretical analysis and numerical simulation were used to investigate the temperature drop problem in the pipelines. The effect of bleed air and ambient temperatures on the performance of temperature drop in high-pressure pipelines was discussed in detail. The performance of pipeline insulation before and after applying the insulation layer was also discussed. The results show that the higher bleed air temperature and lower ambient temperature obviously cause a greater drop in the bleed air temperature drop. The entrance section of the pipeline is approximately five times the l/d range. Applying the insulation layer can effectively reduce the drop in pipeline temperature. Generally, the air insulation layer can reduce the temperature drop of high-pressure pipeline gas by 25%. If further reduction is required, the vacuum insulation layer can be applied.

Parametric resonance and suppression for L-shaped pipe conveying pulsating fluid

This work establishes a new dynamic model for solving parametric resonance and suppression of a L-shaped pipe conveying pulsating fluid, which can be extended to arbitrary pipe configurations. Firstly, the linear dynamic analysis for the L-shaped pipe conveying steady-state fluid is performed. The new results show that there are more wave numbers of the mode shape than those for the straight pipe. With increasing the flow velocity, the natural frequency is decreased and the mode shape is changed from symmetry to asymmetric characteristics. Subsequently, the nonlinear dynamic analysis is conducted for the L-shaped pipe conveying pulsating fluid. It is found that primary and subharmonic resonance behaviors are newly produced due to parametric excitations. At the same time, the subharmonic resonance occurs for the pipe to have much higher vibration amplitudes than the primary resonance. Finally, the strategy of adding an intermediate support is proposed to suppress vibrations of the L-shaped pipe conveying pulsating fluid. Results indicate that there is an optimal position for the L-shaped pipe to add the intermediate support, which can significantly reduce the vibration amplitude. This optimal position is exactly where the fundamental frequency of the pipe system is maximized.

Analysis Welding Types Pipe Fabrication Process in Missile Fast Attack Boat Construction

The equipment in the piping system consists of pipes, valves, flanges, filters, fittings, pumps, and others. The installation schedule for this piping system begins after the connection between blocks. Pipes as part of a ship's system have several steps in their installation procedure, one of which is welding. Welding on pipes is carried out by professional welders who have met more complex competency requirements than welders in general, such as flat position welders, vertical welders, or overhead welders. The purpose of this study was to determine the welding process and types of welding in pipe fabrication for the construction of the Missile Fast Attack Boat. Result comparison between the diameters of the welded pipes, the greater the value of the welding volume formed. The largest volume is 426 mm3, with a pipe length for the fabrication process of 4,3 m. On the other hand, the shortest fabrication is for welding pipes with a diameter of 2,5 m, which has a volume of 127 mm3. While the welding process using GTAW / Gas Tungsten Arc Welding (TIG) is very appropriate for welding in small areas and thin pipes. The TIG welding process has an average volume of below 150 mm3.

Design a Gating System for an Aluminum Cast Three-Way Pipe in Sand Casting

The study of aluminum casting work with market demand in the metal casting industry, designing a gating system in aluminum casting using a three-way pipe-shaped sand mold workpiece as a basic shape template in metal casting, namely a flat-face core box with a core. The gating system has a metal inlet with design variables including the pouring height, pouring basin cross-sectional area, rest basin cross-sectional area, running system cross-sectional area and inlet cross-sectional area. From the studying and designing, actual casting experiments were conducted and simulation behavior was analyzed using Cast-Designer software to make decisions and find appropriate design approaches from analyzing simulation results including liquid metal filling time, molten metal flow behavior, metal solidification time and shrinkage porosity formation of the workpiece. The results of the casting experiment and behavior simulation were able to cast the pipe workpiece which is a flat-face core box mold. The analysis results from the software can be used for actual pouring, where the fully cast mold successfully produced a complete workpiece. This can be a guideline for future improvements to reduce the shrinkage of actual cast workpieces.

Understanding the production and reduction of barium sulfate crystals through the use of additives and a controlled stirring rate

Barium sulfate crystals are minerals responsible for scaling in piping systems. Controlling the growth of these crystals can use additives (FeCl2 and SrCl2) and varying agitation speeds. The research was to optimize the impact of additives and agitation speed on the results of crystal form using RSM through Minitab 19 with Box-Behnken Design. The optimum conditions using additive FeCl2 at a concentration of 25 ppm, a stirring speed of 120 rpm for 30 minutes, and a coefficient of determination (R2) of 90.995 provided 0.4485 gr of barium sulfate crystals. The optimum conditions, however, used SrCl2 additives at a concentration of 20.2049 ppm and a stirring speed of 459.394 rpm for 30 minutes, yielding 0.4345 g of barium sulfates with a coefficient of determination (R2) of 91.41%. The results of crystallizing barium sulfate without additives appear to be superior to those obtained with additives in terms of production. In contrast, additives of FeCl2 and SrCl2 can inhibit barium sulfate formation, resulting in a reduction in crystal mass