Search Results (106)

Composite pipe fittings with an outer layer of 20% long glass fiber-reinforced polypropylene (LGFR-PP) and an inner layer of polypropylene (PP) were prepared via water-powered projectile-assisted co-injection molding short-shot (W-PACIM-S), water-powered projectile-assisted co-injection molding overflow (W-PACIM-O), gas-powered projectile-assisted co-injection molding short-shot (G-PACIM-S), and gas-powered projectile-assisted co-injection molding overflow (G-PACIM-O)techniques. The effects of different injection molding processes on the wall thickness, inner surface roughness, glass fiber orientation, and pressure resistance of pipe fittings were studied to evaluate the quality of the pipe fittings formed by each process. Compared with the short-shot method, the overflow method results in pipes with thinner walls in each layer, a more uniform distribution, smoother inner wall surfaces, and better orientation of glass fibers along the axial direction in the near boundary layer, resulting in better pressure resistance. Under the same injection method, the difference in fluid medium did not significantly change the trend of wall thickness variation in each layer. However, compared with gas, high-pressure water improves the uniformity of the pipe wall thickness and inner wall quality. In addition, the introduction of the warhead is more conducive to improving the degree of glass fiber orientation of the pipe fittings, and the thickness of the residual wall thickness of the pipe fittings has a great influence on the pressure resistance of the pipe fittings. Full article

Current design techniques for water installations are based on pressure-independent consumption. However, certain types of consumption depend on pressure, most notably water leakages, which occur in all water distribution systems. All water installations are prone to water leakages. To mitigate this issue during the design stage of water pipelines, manuals and local regulations recommend a percentage of water losses for sizing pipelines and using them with pressure-independent consumption. This research develops a practical procedure for sizing single water pipelines by considering the effect of pressure-dependent consumption, as in actual pipelines. The findings of this research offer water utilities a new perspective on pipeline design, which is essential for developing new tools to create digital twins. A new methodology for designing pipe diameters is developed in this research. A single pipeline, 2000 m long, is used for the analysis with an emitter coefficient of 0.00829 m³/s/m^0.5. The proposed methodology focuses on calculating energy losses to maintain the required minimum pressure in the system. A sensitivity analysis is conducted on key parameters such as the emitter coefficient, absolute roughness, and the resistance coefficient of a regulating valve. The results of the proposed methodology are compared with the current design (using pressure-independent consumption), revealing differences of up to 28% in calculating water losses. Full article

The microstructure and structure of a Super304H superheater steel pipe after 47,000 h were analyzed by metallographic microscope, scanning electron microscope (SEM), and EDS, and its mechanical properties were measured by hardness meter. The results show that the austenitic grains appear on the outer wall of Super304H steel pipe after service, while the SEM and metallographic microscope tests show that the outer wall particles are coarse. There is an obvious corrosion layer on the outer surface, and the thickness of the corrosion layer on the windward surface is significantly higher than that on the leeward surface. The inner surface is refined and the hardness of the material is significantly increased; the outer surface, the inner surface, and the center all grow abnormally. In this case, the room temperature tensile strength and impact performance of the rough crystal area of the outer wall of the Super304H steel pipe are reduced and fracture along the crystal. Supervision should be strengthened to eliminate the safety risks caused by the abnormal growth of the outer wall austenite grain. The results of crystal phase microscopy show that the main structure of the material still maintains the basic structure of austenitic steel, and particle aggregation mainly occurs in the sub-inner layer of the inner and outer surface. Compared with the lee surface, the middle body structure is basically the same, but whether the thickness of the corrosion layer on the inner surface or the outer surface increases, the deformation degree of the deformation layer is greater. The hardness measurement finds that the hardness of the corrosion layer is caused by the increase in Super304H steel surface stress. In case of pipe explosion accident, the highest chance of pipe explosion here should be closely observed. Full article

The double-connection structure of bionic joints of mining drill pipes has solved the problem of drill drop caused by fatigue cracks. However, with low-melting-point elastic–ductile alloy filling in the bionic joint, the thread on the joint cannot be hardened by high-temperature surface hardening treatments such as quenching and nitriding, making it prone to thread gluing or excessive wear. In this paper, the feasibility of diamond-like film deposition on the surface of a bionic drill pipe thread was studied. A tungsten transition film was used to improve the thickness of the film and the interfacial bond strength between the film and the substrate. The test results show that the total thickness of the DLC film is about 3~5 μm, the roughness is less than 2 μm, the hardness of the film reaches 24.4 GPa, the friction coefficient is 0.04, and the critical load is 56 N. SEM and EDS analyses show that the tungsten film and the bionic joint thread form a metallurgical structure. The morphology of the diamond-like carbon film is uniform and dense, and there is no obvious stratification between the substrate material. The joint with a diamond-like coating treatment has a longer service life than joints receiving conventional high-temperature nitriding treatment. Full article

The introduced work deals with the microscopic analysis of metallographically prepared selected metal materials structures, using a scanning electron microscope (SEM). Prepared samples of seamless steel pipes were subjected to a thorough microscopic examination from the outer surface to the inner regions in order to interpret the specific structure, including the change in the inner surfaces due to wear. The experiment demonstrated that the microstructure and character of the surfaces play a key role in the behavior of metallic materials in real conditions of hot water heating. Four pipe samples were monitored according to their use. The unused steel pipe (designated as sample No. 1) exhibited a rough outer surface with identified inclusions, while the used pipe (designated as sample No. 2) showed marks of intergranular corrosion and significant wear after long-term use. The older pipe (designated as sample No. 3) showed a decarburized area and inclusions containing sulfides and aluminum. The steel pipe with corrosion layers (designated as sample No. 4) exhibited a continuous corrosion layer with cavitation and cracks. The results of this study offer a comprehensive view of the influence of the nature of microstructure and wear on water flow in metal pipes, with an emphasis on the identification of possible risks associated with geometry change, corrosion, and wear. The findings form the basis for predicting degradation and appropriate maintenance in order to ensure their long and reliable service life under real conditions of use. They offer the possibility of continuing and expanding research and analysis of the use of metallic materials in comparison with polymers and composites. Full article

Pipe routing in ship design presents significant challenges because of its time-consuming nature and the need for considerable attention to detail. In recent years, the decreasing number of pipe designers has impacted the quality of pipe-routing designs. However, optimizing pipe routing is crucial for reducing construction costs and ship production time. This study focused on optimizing the procedure and routes, considering over 500 pipes throughout the engine room of an 82,000-ton Panamax bulk carrier with three decks. Procedure optimization was based on a genetic algorithm and a system that considered individual pipe characteristics, such as type, diameter, and length. For pipe-route optimization, we used the Dijkstra algorithm, which aims to provide the shortest pipe routing by minimizing branching, bending, crossing, and obstacle avoidance. Pipe-routing optimization was divided into “basic” and “detailed” designs to derive rough and detailed routes, respectively. The basic design allowed intersections and horizontal bending, while the detailed design provided a route without intersections and minimized all bending. The optimized design was compared with pipe routing designed by diameter and shorter-path orders. In ship construction, pipe-routing optimization reduced the overall cost of pipe routing by 7% compared to other systems that typically use diameter and shortest-route orders. The study’s findings highlight the practical cost benefits and potential applications of the pipe-routing process in ship construction. Full article

The aim of the present work is to test a novel Reverse Unidirectional Flushing (R-UDF) approach to achieve an enhanced removal rate of iron oxide particles from drinking water pipes. The project utilized a full-scale PVC pipe loop laboratory system to successfully isolate direction as a particle mobilization factor. Even after successive flushing operations in one direction, a subsequent flush in the opposite direction mobilized new particles from the pipe wall surface. This shows that there are some areas in the pipe loop system that may protect deposited particles from flushing shear stresses in a determined flow direction. Full article

Leakage presents a significant challenge in water distribution network (WDN) planning and management. This study introduces a novel methodology for hydraulic model calibration and leak detection based on MCMC-Statistical Distance. The central hypothesis posits that the presence of leaks induces fluctuations in estimated pipe roughness coefficients (PRCs) as the pipe flow changes, reflecting the altered behavior of leaking pipes in energy dissipation. The proposed model comprises two distinct algorithms: (1) PRC estimation using MCMC and (2) a leakage detection algorithm employing a Kolmogorov–Smirnov test. Demonstrated in a simple water distribution network with various scenarios, the results illustrate the model’s potential for real-time leak detection. Full article

In this study, a graph-based method is implemented for sensor placement in a water distribution network (WDN) instead of using a hydraulic model. The proposed methodology determines the pressure sensors’ location based on the node betweenness centrality of nodes from their source, considering the WDN topology and assigning hydraulic-inspired edge weights. Furthermore, the Non-dominated Sorting Genetic Algorithm (NSGA-II) determines the end node of the WDN’s critical paths for sensor placement to maximize monitoring network efficiency to calibrate the model and avoid additional data collection. For different numbers of sensors, the NSGA-II algorithm is implemented 10 times and the final Pareto front is determined. The graph-based approach reduces the sensor placement problem complexity to an acceptable level and can be implemented as a surrogate approach for hydraulic-based sensor placement. Full article

This paper investigates the robustness of one innovative model-based method for leak detection, namely the Dual Model. We evaluate the algorithm’s performance under various leakage scenarios in the L-Town network, despite uncertainties and model mismatches in (i) base demand, (ii) pipe roughness, (iii) the number of sensors, and (iv) network topology. Our investigation results indicate that the Dual Model is highly sensitive to discrepancies in the first three parameters. However, the impact can be mitigated through sensor-specific calibration, such as adjusting sensor elevations. Moreover, the Dual Model has demonstrated robustness to minor topology mismatches, like those introduced by closed valves. Full article

This study introduces a novel framework for conducting a comparative analysis of static and mobile sensing approaches for the collection of data to be used in network calibration. Two new algorithms that optimize deployment for both static and mobile sensors are proposed. The results indicate that deploying a single mobile sensor starting from various locations throughout the network for 24 h can yield pipe roughness calibration results as good as, or slightly superior, to those obtained using static sensors at approximately 90% of the potential monitoring nodes. Full article

This study investigates the methods for controlling porosity in thermal pipes manufactured using selective laser melting (SLM) technology. Experiments conducted include water permeability tests and surface roughness measurements, which are complemented by SEM image ML-based analysis for pore recognition. The results elucidate the impact of SLM printing parameters on water permeability. Specifically, an increase in hatch and point distances leads to a linear rise in permeability, while higher laser power diminishes permeability. Using machine learning (ML) techniques, precise pore identification on SEM images depicting surface microstructures of the samples is achieved. The average percentage of the surface area containing detected pores for microstructure samples printed with laser parameters (laser power (W) _ hatch distance (µm) _ point distance (µm)) 175_ 80_80 was found to be 5.2%, while for 225_120_120, it was 4.2%, and for 275_160_160, it was 3.8%. Pore recognition was conducted using the Haar feature-based method, and the optimal patch size was determined to be 36 pixels on monochrome images of microstructures with a magnification of 33×, which were acquired using a Leica S9 D microscope. Full article

Irrigation refers to supplying water to soil through pipes, pumps, and spraying systems to ensure even distribution across the field. In traditional farming or gardening, the setup and usage of an agricultural irrigation system solely rely on the personal experience of farmers. The Food and Agriculture Organization of the United Nations (UN) has projected that by 2030, developing countries will expand their irrigated areas by 34%, while water consumption will only be up 14%. This discrepancy highlights the importance of accurately monitoring water flow and volume rather than people’s rough estimations. The smart irrigation systems, a key subsystem of smart agriculture known as the cyber–physical system (CPS) in the agriculture domain, automate the administration of water flow, volume, and timing via using cutting-edge technologies, especially the Internet of Things (IoT) technology, to solve the challenges. This study explores a comprehensive three-dimensional problem space to thoroughly analyze the IoT’s applications in irrigation systems. Our framework encompasses several critical domains in smart irrigation systems. These domains include soil science, sensor technology, communication protocols, data analysis techniques, and the practical implementations of automated irrigation systems, such as remote monitoring, autonomous operation, and intelligent decision-making processes. Finally, we discuss a few challenges and outline future research directions in this promising field. Full article

While recent studies have proven an unexpected liquid–vapor phase transition of adsorbed liquid films, a comprehensive description of the mechanisms of different types of phase change regimes over realistic representations of random rough surfaces is absent in the literature. The current comprehensive study investigates the effects of a gold random rough surface, liquid film thickness, and substrate temperature on the liquid–vapor phase change regime of an adsorbed sodium liquid film, considering the evaporator section of a wicked heat pipe (WHP) using a molecular dynamics (MD) simulation. At first, to generate a realistic random rough surface, a new and promising method is proposed that is entirely based on MD simulations. Then, to simulate the evaporator section of a WHP, a unique configuration for eliminating the vapor domain is developed. The simulation results reveal that three distinct regimes, namely, normal evaporation, cluster boiling, and film boiling, could be identified, which are presented on two-dimensional diagrams with the substrate temperature and liquid film thickness as coordinates for the ideally smooth and random rough surfaces. The results also manifest that even though using the random rough surface could lead to different phase transition regimes, the type of regime depends mainly on the substrate temperature and liquid film thickness. Furthermore, this study displays two different modes for normal evaporation. Also, it is shown that the impacts of the liquid film thickness and substrate temperature on the mode of normal evaporation are much more significant than the surface roughness. Full article

An accurate formula for calculating the pressure loss in concrete pumping plays a significant guiding role in the design and service process of pump trucks. Based on the flow characteristics of concrete pumping, a straight pipe one-dimensional model for the pressure loss is developed, in which both the viscous force of the mortar in the lubrication layer and the blocking effect of coarse aggregate particles are considered. First, the complex geometrical shapes of the aggregate particles are geometrically reconstructed by using a HandySCAN noncontact scanner and the reverse modeling software Geomagic Design X (v.19.0.2). Then, the equivalent spherical size of nonspherical aggregate particles is calculated according to the equal hydraulic radius principle. The blocking effect of the aggregate particles is converted into the wall roughness. Finally, an explicit expression for the pressure loss in concrete pumping is deduced by using Modi’s equation, Bernoulli’s equation, and Darcy’s formula, and the calculated value is compared with the measured value at a corresponding experimental site. The results indicate that the pressure loss values calculated with the one-dimensional flow model are closer to the actual pumping pressure loss values. The relative error between the results and the actual pumping pressure loss value is about 20.2%. Full article