Rubber Hose Research Articles

Structural design of a balanced cone-spherical fiber-reinforced rubber hose

This article focuses on the optimal structural design of a balanced cone-spherical fibre-reinforced rubber hose (RH). Combined with deformation characteristics of the conical RH, the cone-spherical RH is improved based on the spherical RH. Then the mechanical model of balance performance, stiffness and burst pressure for the cone-spherical RH is constructed. The structural optimization design of double cone-spherical RHs is conducted to further reduce the stiffness of the RH. The model is applied to large-sized RH. Eventually, in the optimization case of this article, the double cone arc-shaped structure has the smallest stiffness. Compared to existing single curved RHs, the stiffness has been reduced by 53%. The correctness of the theoretical model is verified through experiments.

P-Phenylenediamines and p-phenylenediamine quinone derivatives in rubber consumer products and typical urban dust: Sources, transformation profiles, and health risks

N,N′-Substituted p-phenylenediamines (PPDs) are widely used as antioxidants in the rubber industry and are released into the environment in large quantities during the production and use of rubber products. We quantified PPDs and PPD quinone derivatives (PPD-Qs) in rubber consumer products, including car tires, rubber belts, rubber gloves, rubber cables, and rubber hoses, to obtain information on the degree of weathering over time during their use. Additionally, we investigated the occurrences and sources of PPDs and PPD-Qs in dust samples collected from four typical urban environments (roads, parking lots, automotive repair shops, and residences). The detected compounds included the highly toxic N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine quinone, which can cause acute mortality of coho salmon (Oncorhynchus kisutch). Concentrations of PPDs in the automotive repair shops reached 56.0 μg/g, and were much higher than in the other environments, while the residential samples had the lowest contaminant concentrations. In road and residential samples, N,N′-di-2-naphthyl-p-phenylenediamine accounted for 17 %–30 % of the PPDs, and may have originated from different sources. We preliminarily identified 32 transformation products, and 11 of these were N,N′-di-2-naphthyl-p-phenylenediamine transformation products. The average daily intakes of PPDs and PPD-Qs were calculated to assess the health risks of dust exposure in each environment. Workers had high total intakes of PPD [60.3 ng/(kg day)] and PPD-Qs [20.1 ng/(kg day)], and were at some risk of occupational exposure. These results improve our understanding of the environmental occurrences, sources, transformation, and health risks of PPDs and PPD-Qs.

Structural Design and Mechanical Properties Optimization of a Balanced Fiber-Reinforced Rubber Hose

This paper focuses on the optimal design of the structure of a balanced fiber-reinforced rubber hose (RH). A multi-spherical RH is proposed. Based on the grid method, the structure optimization design of single-spherical and multi-spherical RHs is performed. According to the constraints, the optimization results of the structural parameters of the RH are solved. Then, combined with the deformation characteristics of the conical RH, the cone-spherical RH is improved based on the spherical RH. The mechanical equilibrium angle and deformation expressions of the cone-spherical RH are deduced. The mechanical model of the balance performance, stiffness, and burst pressure for the cone-spherical RH is constructed. The structural optimization design of double-spherical and double cone-spherical RHs is performed to further reduce the stiffness of the RH based on the multi-spherical RH. Eventually, the correctness of the theoretical model and its optimization results is verified through experiments. The results of this research can provide reference data for future studies in related fields.

The Influence of the Frequency of Ultrasound on the Exhaust Gas Purification Process in a Diesel Car Muffler

This research aimed to analyze the possibility of installing an ultrasonic emitter in an already manufactured car and to prove the possibility of cleaning the exhaust gases of an internal combustion engine through the action of an ultrasonic wave due to coagulation and examining the optimal regimes of its work. The existing theoretical solution to describe the proposed process was analyzed. A Mercedes-Benz M-Class ML 270 CDI MT car with the OM 612 DE 27 LA Diesel engine was used for the experiment. An ultrasound generator and an ultrasound emitter were connected to the muffler. The stand was connected to the car via the inlet with a rubber hose that directs the exhaust gases out of the car. The crankshaft speed of the engine was changed in the range of 750 to 1250 rpm, which corresponds to urban conditions when cars are moving in heavy traffic jams. The content of CH, CO, CO2, and O2 in the exhaust gas of the vehicle was determined as a function of the crankshaft speed without ultrasonic exposure and with ultrasonic exposure at an ultrasound frequency of 25, 28, and 40 kHz. The results of the experiment showed that the introduction of an ultrasonic emitter into the muffler reduced the smoke content of the gas, increased the oxygen content, and reduced the amount of carbon dioxide in the exhaust gases. With an increase in the ratio between the ultrasonic frequency and the angular velocity of the engine crankshaft (f/ω), the smoke content of the gas also decreased. At the maximum values of ultrasonic frequency and angular velocity of the engine crankshaft selected in the experimental studies, the minimum value of the ratio of gas smoke indicators was achieved, and the degree of purification was 10–13%. Such results correspond to the condition of optimal operation of the ultrasonic muffler, where the ratio of gas to smoke values should tend to a minimum. These results confirm the potential of using ultrasound as a method for cleaning exhaust gases and underline the need for further research in this area.

Research and application of a flexible measuring array for deep displacement of landslides

Abstract. The multidimensional and multi-sliding surface measurement of deep-seated displacement on landslides poses a significant technical challenge in landslide monitoring and early warning. The fixed-borehole inclinometer serves as an important measurement method based on drilling for this purpose. In this study, a novel flexible measurement array for deep-seated landslide displacement and its installation and measurement processes were developed, enabling higher accuracy in full-hole multidimensional deformation measurement. The measurement array consists of individual measurement probes as basic units, connected in series through coaxial cables and high-pressure rubber hoses, forming a flexible measurement array. Each probe is equipped with acceleration and magnetic field sensors, allowing for the measurement of borehole inclination and azimuth angles and providing a more comprehensive understanding of the deformation of deep-seated landslides. This flexible measurement array resolves the limitations of traditional fixed inclinometers, such as limited probe quantity or inaccurate installation positions that fail to reflect the deformation trend of the landslide body. Moreover, it eliminates the need for auxiliary installation accessories like pulleys and inclinometer pipes, simplifying the mechanical structure and installation process, which represents an advancement in methodology and an improvement in measurement techniques. This array provides a more comprehensive and improved monitoring tool for disaster prevention and mitigation, thereby enhancing the level of geological hazard monitoring and early warning technology.

“This kind of life has no meaning”

“This kind of life has no meaning”

Water hammer mitigation by internal rubber hose

The aim of this research was to experimentally analyse the possibility of using a rubber hose placed inside a pipeline to mitigate the water hammer phenomenon. The experiments were conducted using a steel pipeline with an inner diameter of 53 mm and an EPDM rubber hose with a diameter of 6 mm. Hydraulic transients were induced by a rapid closure of the valve located at the downstream end of the pipeline system. In order to analyse the influence of steady-state flow conditions on the maximum pressure increase, measurements were carried out for different values of initial pressure and discharge. The experimental results indicate that placing a rubber hose inside a pipeline can substantially attenuate valve-induced pressure oscillations. It was observed that the initial pressure has a significant influence on the capacity of the rubber hose to dampen the water hammer phenomenon. Comparative numerical calculations were performed using the Brunone–Vitkovský instant acceleration-based model of unsteady friction. It was demonstrated that this approach does not allow satisfactory reproduction of the observed pressure oscillations due to the viscoelastic properties of the EPDM hose used in the tests.

An Equivalent Linear Method to Predict Nonlinear Bending Mechanics of Dredging Floating Hose String

Dredging hoses are flexible and are particularly suitable for slurry transportations for mud or sand in dredging projects. To achieve sufficient bending stiffness and to prevent the pipe body from collapsing, this type of hose segment is a composite structure that is embedded with several cord reinforcement layers and steel wires in its rubber layer. To quickly evaluate the nonlinear bending mechanical properties of rubber hoses, this study proposes the equivalent stiffness method of linear superposition, which is verified by test data and numerical results. The results show that the equivalent bending stiffness method proposed in this study is in good agreement with numerical and experimental results. Then, by comparing the calculation results of the hose string, it was demonstrated that the linear stiffness superposition method proposed in this study can also accurately predict the bending mechanical behavior characteristics of string hose, and provide reliable guidance for hose design in practice.

Stability analysis of braking and control system of pipeline intelligent plugging robot

In the maintenance and emergency repair of oil and gas long-distance pipelines, the pipeline intelligent plugging robot is a new type of intelligent and efficient plugging device inside the pipeline. The stability of its braking and control system determines whether it can successfully seal high-pressure oil and gas inside the pipeline. This research is about intelligent plugging robots for pipelines that use the friction between the rubber hose and the pipe wall for braking. A hydraulic control system is designed, and a braking model for the robot is established. The hydraulic control system is simulated using a numerical simulation method, and the influence of different braking distances on system stability is investigated for various initial velocities of the robot. The results indicate that the fuzzy PID control hydraulic system exhibits a faster response with a maximum overshoot acceleration of −12.8 m/s2. The system achieves the desired acceleration of −0.14 m/s2 within 7 seconds and successfully completes the braking process. The fuzzy PID control approach effectively reduces parameter fluctuations, improves system stability, and decreases acceleration variations when faced with different initial speeds and braking distance signals. Consequently, the positioning accuracy of the robot is enhanced, and power consumption is reduced. This research provides important guidance for the development of new technologies in pipeline maintenance and emergency repair, particularly in the area of plugging operations under pressure.

Comparison of different optical techniques to measure skin vibrations

We test different possible setups to measure skin vibrations in the abdominal region which could, in the future, enable quick and comfortable monitoring of aortic aneurysms in the abdominal region. For this study, a simple mechanical model is used that simulates the human tissue and a large blood vessel, the aorta. The model consists of a plastic box filled with a gelatin as used for ballistic experiments. A rubber hose goes straight through the gel block and, with a pump that is connected to the hose, one can create a pulsatile flow of water through the flexible hose leading to traveling waves along the artificial vessel. Surface vibrations on the gelatin block are then measured using a Laser-Doppler vibrometer (LDV), a commercial 3D DIC system and a simple camera setup with only one camera and an additional mirror for 3D capabilities. While the LDV offers the best signal quality, it can only measure one point simultaneously. We discuss implications how this will influence the possible data analyses compared to more noisy, but full-field measurements provided by the camera-based systems.

Comprehensive Research on Construction and Stability of Horizontal-Well Cavity Natural Gas Storage in Thinly Bedded Salt Rocks in China

This study aimed to overcome the difficulty of conducting the horizontal-well cavity leaching test in the field and to investigate the long-term stability of the horizontal-well salt-cavity natural gas storage. The simulation test design is combined with the similarity theory to study the cavity expansion characteristics and the influence law of cavity leaching parameters. Through the design of a rubber hose connection, an integrated closed test system for multi-stage horizontal-well cavity leaching and brine drainage was built. The test system also realises the repeatable backward movement of the injection well during the test. A similarity simulation of the test design was carried out, and the test platform was constructed to carry out multi-stage horizontal-well leaching tests with a nitrogen cushion. In the horizontal-well leaching tests with a nitrogen cushion, the influence laws of the well spacing, flow rate and liquid level position on cavity expansion were investigated. Based on the morphological characteristics of the horizontal-well cavity, a numerical model of the horizontal-well salt cavity was developed, which reflects the real cavity morphology leached in the test. The long-term stability of the horizontal-well salt-cavity natural gas storage under different internal pressures was investigated through numerical simulation.

Measurement of the transmission loss of a rubber hose

Flexible rubber hoses can provide significant attenuation of vibro-acoustic energy in fluid-filled piping systems. The vibro-acoustic performance of rubber hoses can be measured by using a variation of a water-filled impedance tube, using the two-source method, to determine the impedance and transmission loss. This paper presents the test method and results from measurements performed to characterize the vibro-acoustic behavior of a water-filled, 1.5 m length of DN100 fiber reinforced rubber hose, with beaded and flanged terminations, at two pressures. The test results indicated that the rubber hose test specimen achieved a fluid-borne transmission loss of at least 5-10 dB at low frequencies increasing to more than 45 dB at 1kHz.

PERANCANGAN ALAT TIMBANGAN HEWAN TERNAK MENGGUNAKAN SENSOR FIBER OPTIC DAN SOFTWARE ARDUINO IDE

Abstract
 The type and technique of feeding is the main thing related to the acceleration of livestock development but almost most of the farmers do not pay much attention to the type and quality of feed given to their animals. Therefore, researchers designed the farm animal scales by creating an optical fibre-based sensor and utilizing the Arduino IDE software system for the purpose of making animal farmers aware of the weight information of their animals. The design of the scales has been done in the laboratory of Optoelectronics and Instrumentation, Physics Research Center of Indonesian Institute of Sciences (LIPI) Serpong. The optical fibre sensor system with the received light intensity output was then transmitted by the photodetectors and then Analog to Digital Converter (ADC) process using the Arduino Software. Result of sensor characterization with varying diameter rubber hose with high sensitivity obtained sensor with diameter of 3.1 cm and 2.6 cm. The test results showed that the sensor with a diameter of 3.1 cm was able to withstand pressure of 3.1 kg. F/cm2 or a load equivalent of 905.2 kg.
 Keywords: Sensors, Optical Fiber, Software Arduino IDE, Livestock

Analysis of Working Postures in Rubber Manufacturing Industry by using OWAS and RULA Methods

The basic conditions of working in a healthy and safe workplace are to design the job in accordance with the anthropometric measurements, body strength and personal characteristics of the person, to ensure that the materials, machinery and equipment used in the working process are suitable for the employee's capacity, and to provide an environment that will produce positive psycho-social results. Correct analysis methods should be used and evaluated in order to meet this basic requirement. Identifying the negative effects of working postures, taking corrective measures and improving them is a critical step of an efficient working environment. Working postures that are not properly analyzed cause strain on workers and even discomfort. It provides important contributions in the field of analyzing and improving working postures with scientific methods, controlling work performance and reducing musculoskeletal disorders (MSDs). OWAS (Ovako Working Posture Analyzing System) and RULA (Rapid Upper Limb Assessment) are successfully applied in various fields in the analysis of working postures. In this study, it was aimed to determine the MSDs risk levels of the workers working in the rubber industry by OWAS and RULA methods and measures were proposed for these risks. While OWAS analysis was obtained by using expert opinions in the study, CATIAV5R20 program was used for RULA analysis. The study includes the examination of 5 different postures in total. In the OWAS and RULA results of the study, it was seen that the most risky postures are attach the rubber hose to the cores and to place the rubber hoses attached to the cores in the autoclave. The results of the analysis showed that the RULA method is more suitable and reliable than the OWAS method for the analysis of the tasks in the vulcanization process workstations.

Особливості розроблення піроболтів з низькими ударними та віброімпульсними характеристиками

One of the systems in the integrated launch vehicle responsible for prelaunch processing and launch is a ground thermal conditioning system, which supplies the low-pressure air into the launch vehicle’s “dry” compartments. Thermal conditioning system is mated with the launch vehicle, using the mating interfaces, proper functioning of which enhances reliability of the ground support equipment, the launch vehicle and the entire space launch system. The article describes key requirements to the interfaces of the thermal conditioning system and the drawbacks of the existing designs. The article proposes a new design concept of the interface that connects the pipeline of the ground thermal conditioning system to the orifice of the launch vehicle using the corrugated rubber hose composed of three basic parts, attached with the help of a metal lock/release assembly. The proposed solution provides reliable leaktightness, ease of operation, providing multiple connections to the launch vehicle, including at various angles, and automatic disconnection by rocket motion or manual removal in case of launch abort. Using rubber as a high-elasticity structural material to manufacture the hoses, enabled minimization of efforts required to disconnect the interface from the launch vehicle. In its high-elasticity state, rubber can absorb and dissipate mechanical energy within a wide range of temperatures, which prevents transmission of engine vibrations to the ground thermal conditioning system. The article presents key properties of rubber used as a structural material and its peculiarities to be considered during design of similar products. Unlike metal showing two types of deformation (elastic and plastic), rubber can exhibit three types of deformation (elastic, superelastic and plastic). In the process of interface design, we took into account two types of deformations (elastic and superelastic ones). Experimental studies of the interface showed its full compliance with technical specification. Key words: orifice of the launch vehicle, corrugated rubber hose, lock/release assembly, superelastic deformation, leaktightness.

Demethyleneberberine alleviated the inflammatory response by targeting MD-2 to inhibit the TLR4 signaling.

The colitis induced by trinitrobenzenesulfonic acid (TNBS) is a chronic and systemic inflammatory disease that leads to intestinal barrier dysfunction and autoimmunedisorders. However, the existing treatments of colitis are associated with poor outcomes, and the current strategies remain deep and long-time remission and the prevention of complications. Recently, demethyleneberberine (DMB) has been reported to be a potential candidate for the treatment of inflammatory response that relied on multiple pharmacological activities, including anti-oxidation and antiinflammation. However, the target and potential mechanism of DMB in inflammatory response have not been fully elucidated. This study employed a TNBS-induced colitis model and acute sepsis mice to screen and identify the potential targets and molecular mechanisms of DMB in vitro and in vivo. The purity and structure of DMB were quantitatively analyzed by high-performance liquid chromatography (HPLC), mass spectrometry (MS), Hydrogen nuclear magnetic resonance spectroscopy (1H-NMR), and infrared spectroscopy (IR), respectively. The rats were induced by a rubber hose inserted approximately 8 cm through their anus to be injected with TNBS. Acute sepsis was induced by injection with LPS via the tail vein for 60 h. These animals with inflammation were orally administrated with DMB, berberine (BBR), or curcumin (Curc), respectively. The eukaryotic and prokaryotic expression system of myeloid differentiation protein-2 (MD-2) and its mutants were used to evaluate the target of DMB in inflammatory response. DMB had two free phenolic hydroxyl groups, and the purity exceeded 99% in HPLC. DMB alleviated colitis and suppressed the activation of TLR4 signaling in TNBS-induced colitis rats and LPS-induced RAW264.7 cells. DMB significantly blocked TLR4 signaling in both an MyD88-dependent and an MyD88-independent manner by embedding into the hydrophobic pocket of the MD-2 protein with non-covalent bonding to phenylalanine at position 76 in a pi-pi T-shaped interaction. DMB rescued mice from sepsis shock induced by LPS through targeting the TLR4-MD-2 complex. Taken together, DMB is a promising inhibitor of the MD-2 protein to suppress the hyperactivated TLR4 signaling in inflammatory response.

Laboratory Wheel Tracking of Asphalt with Rubber Tires or Rubber Hoses

In recent years, wheel tracking of asphalt mixtures has gained considerable momentum, and the authors are evaluating the potential of standardizing a rubber-tire wheel tracking protocol which can enable direct decoupling of rutting and moisture damage by testing identical specimens in dry and wet conditions. Previous work has established the value of dry and wet comparisons; this paper specifically assesses the dry rutting component by comparing a rubber-tire wheel tracker known as the PURWheel-G2 with the asphalt pavement analyzer (APA), arguably the most well-known dry wheel tracking test. This paper has two main objectives: demonstrate that rubber-tire wheel tracking is capable of characterizing dry rutting in a manner comparable to the APA and recommend initial failure criteria for rubber-tire wheel tracking. The PURWheel-G2 was more variable than the APA with coefficients of variation nearly twice as large. Although there was variability, reasonable rut depth correlations were drawn between the PURWheel-G2 and APA, and an APA pass/fail criteria of 6 mm equated to 10 mm for conventional PURWheel-G2 testing using laboratory-compacted slabs. Using literature and available data, 6 mm was proposed as a rubber-tire pass/fail threshold when standardizing to typical APA compaction methods and boundary conditions (i.e., cylindrical specimens in confined molds). Ultimately, efforts are ongoing to improve limitations of the PURWheel-G2 prototype (e.g., variability) with modernized equipment, and the authors recommend agencies initially consider the same failure criteria already established for APA testing and be willing to adjust over time as data and experience dictate the need to do so.

Evaluation of Crude Oil Wax Dissolution Using a Hydrocarbon-Based Solvent in the Presence of Ionic Liquid

The current alternative of using aromatic-based wax soak solvents has been found to be hazardous and imposes a high cost on field expenditures. These solvents are widely used in the oil and gas industry to soften up wax before the pigging process. However, their impacts on the environment are quite concerning. Plus, they also impose hazardous exposure and are found to be damaging to both plastic and rubber hoses. To replace the current alternative with other hydrocarbon-based wax soak solvents, ionic liquids were found to have the capability to increase the solvent power capabilities and the efficiency of wax soak solvent in dissolving heavy crude oil. To optimise the application of hydrocarbon solvents and ionic liquid in wax dissolution, the affinity of ionic liquids in three solvents was studied. The solvents were condensate, ethyl acetate, and xylene. It was found that from four types of ionic liquids tested, only BMIMCL and HMIMBr were miscible in all three of the solvents used. Dissolution of hard deposited paraffin wax in condensate, ethyl acetate and xylene was conducted using the spectral analysis method, and it was found that the dissolution of paraffin wax was greatest in ethyl acetate. However, enchantment on wax dissolution was also observed for gas condensate and xylene. The wax soaking time was also optimised, in which the dissolution of wax was found to reach a saturation level when the wax had been soaked for over 90 min in the solvents, especially for gas condensate. Further study on the effect of ionic liquid introduced alongside condensate, ethyl acetate and xylene, aiming to enhance the solvent power, was also conducted using the spectral analysis method. The introduction of ionic liquids to all hydrocarbon-based wax soak solvents used in this project was proven to significantly increase the UV-VIS absorbance of the extracted solvents after paraffin wax had been soaked for 30 min.

A Simplified Method to Predict the Crush Behavior of Offshore Bonded Rubber Hose

Crush load is one of the common loads for offshore composite rubber hoses. It may induce the damage of the hose on the reel and the tanker reel hose. A theoretical approach is proposed to evaluate the response of the hose to the crush load, which is fulfilled in three steps. (1) The hose wall is treated as a composite shell, and its mechanical properties are deduced based on the rule of the mixture of the composite. (2) The composite hose is equalized as a homogeneous hose, and the equivalent shell thickness is determined based on the strain energy equivalence. On one hand, the relationship between the strain energy and the wall thickness is theoretically deduced for the equivalent homogeneous hose. On the other hand, an FE model of the composite hose is loaded to obtain the strain energy. The equivalence of the two models implies the equality of the strain energy. Therefore, the strain energy is used to calculate the wall thickness of the equivalent homogeneous hose. (3) The response of the homogeneous hose to the crush load is deduced based on the elastic shell theory. The proposed method is validated against an indoor test. It is found that the proposed approach slightly overestimates the rigidity of the hose. This is probably due to the initial imperfection of the test specimen, which reduces the rigidity of the hose. The proposed approach could be a valuable tool for the future design of offshore composite rubber hoses.

The migration and degradation of N‐(1,3‐dimethylbutyl)‐N′‐phenyl‐p‐phenylenediamine from rubber hoses in milk lines

N‐(1,3‐dimethylbutyl)‐N′‐phenyl‐p‐phenylenediamine (6PPD), an anti‐ageing agent in rubber hoses used in milk lines, may migrate into the milk and cause safety issues. Thus its migration and degradation in simulants/milk were studied to explore the changing trends and final levels, by high‐performance liquid chromatography. The results showed that 6PPD continuously increased in 95% ethanol and degraded more easily in simulants with a high water content. The degradation may be attributed to the π‐conjugated system of 6PPD and smaller steric hindrance of degradation products. No migration was observed into milk after 10 min. This study provides a novel and effective approach to evaluating 6PPD trends and safety for the dairy industry.