Piping

Fluid-structure interactions (FSI) due to internal flows are common sources of industrial concern. Piping systems and valves can generate strong vibrations, transient pulses, cavitation effects and various types of flow instabilities. Several studies carried out in the last five years on industrial piping systems are described to illustrate the variety of phenomena and to indicate fields where research is required. The described cases include waterhammer, turbulence-induced vibrations, cavitation-induced vibrations, vortex shedding with acoustic lock-in, FSI and vortex shedding with lock-in, and a shallow cavity coupled to transverse acoustic modes.

Dam is a structure built across a stream to retain water for the purpose of water supply, irrigation, hydropower, and flood control. Beside the high benefits, dams are also a potential threat to public safety, which is dam break/dam failure. The purpose of this study was to discover various scenarios of dam break at Ciawi Dam, with the main modes of failure have been identified as piping or overtopping. Ciawi dam break are modeled and analyzed using HEC-RAS v5.0.7 based on available geometry data. After that, based on regional population data, the economic loss calculated using InaSAFE. The simulation results showed that the Probable Maximum Flood (PMF) with a peak discharge of 1845,867 m3/s did not generate an overtopping scenario. From the analysis of 2-D simulation in HEC-RAS, the Ciawi dam break due to piping at Probable Maximum Flood (PMF) has a maximum water depth of 46,419 m with the area of inundation covers 108,04 km2. Those numbers imply that Ciawi Dam break classified as ...

Piping in nuclear power plants is subject to corrosion and erosion caused by the interaction with fluids it carries. In order to prevent accidents such as pipe rupture, it is necessary to non-destructively inspect the thickness of the pipe wall and predict the remaining pipe life. In contrast, signals obtained by non-destructive inspection are affected by various uncontrollable and unknown factors, which will result in uncertainty in evaluating pipe wall thickness. Ignoring the uncertainty would lead to a large error in the pipe reliability assessment. Therefore, it is important to develop a reasonable pipe wall thinning management that can takes the uncertainty of non-destructive testing into consideration. Based on this background, this study aimed to develop a piping wall thinning prediction model that accounts for the uncertainty in evaluating pipe wall thickness and to evaluate its applicability to ultrasonic testing. At first, ultrasonic tests were performed to measure the thickness of specimens simulating flow accelerated corrosion. The results of the measurements were statistically analysed to obtain a mathematical model correlating the evaluated and true thickness. A numerical model to predict the reduction of wall thinning with its uncertainty is developed. Compared to the conventional method, the proposed method is able to predict wall thickness with high accuracy.

Many design engineers used to take many services ducts, such as air conditions, water supply, sewage piping, electrical and mechanical conduits, through the space below reinforced concrete (RC) beams forming the floor systems. Then to enhance aesthetics, a false ceiling needs to be provided below the ducts, reducing the clear height of stories, or increasing the total height of structures, particularly for multistoried buildings. For better use of space, such ducts can be taken through web openings in RC beams wherever possible, thereby reducing the overall height of the building. With a focus on a better understanding of the behavior of these beams under pure torsion, this paper presents an experimental study carried out on 23 RC beams with web openings that were tested under pure torsion. Several parameters are studied, such as the length, width (i.e., size), the eccentricity of the openings, and the longitudinal and transverse steel in the chord members. The experimental results indicated that the web opening greatly influences the torsional behavior of the reinforced concrete beams. This paper provides the initial basis for forthcoming experiments and future numerical simulations of RC beams with web openings under combined flexural-shear-torsional behavior that are primary goals in future studies.

Many design engineers used to take many services ducts, such as air conditions, water supply, sewage piping, electrical and mechanical conduits, through the space below reinforced concrete (RC) beams forming the floor systems. Then to enhance aesthetics, a false ceiling needs to be provided below the ducts, reducing the clear height of stories, or increasing the total height of structures, particularly for multistoried buildings. For better use of space, such ducts can be taken through web openings in RC beams wherever possible, thereby reducing the overall height of the building. With a focus on a better understanding of the behavior of these beams under pure torsion, this paper presents an experimental study carried out on 23 RC beams with web openings that were tested under pure torsion. Several parameters are studied, such as the length, width (i.e., size), the eccentricity of the openings, and the longitudinal and transverse steel in the chord members. The experimental results ...

The international thermonuclear experimental reactor water cooling system (ITER WCS) is divided into 20 loops with the aim to reduce the consequences of a loss of coolant accident (LOCA). This makes the ITER WCS a very complicated system with many components requiring periodical inspection and maintenance. The main radiological concern for the staff involved in such activities is due to the activated corrosion products (ACPs) generated by corrosion of the inner wall of the piping under the neutron flux. In the present study the collective dose due to the ACP for one loop of the ITER WCS is assessed. Two different maintenance and inspection (M/I) approaches (or working strategies) for the ITER WCS components are to be considered. The first one is usually applied in American and European designs of pressurised water reactors (PWRs) that have cooling loops similar to those envisaged in ITER. The other one is the strategy proposed by the ITER WCS designers that takes into account the actual plant layout and technology. Both strategies have been implemented in the occupational radiation exposure (ORE) assessment process and two results have been obtained. The similarity is then performed pointing out the differences between the two approaches, trying to indicate what is the best one from the ORE point of view.

Students designed a rotating pipe flow apparatus for the fluids laboratory. The project was funded by the ASHRAE Senior Undergraduate Project Grant Program. This paper describes a project where a group of undergraduate engineering students in the manufacturing processes, finite element methods and fluid mechanics courses designed, built, and tested a swirling pipe flow apparatus for measurements of friction factors. The overall objective was to engage the students in a design project. The paper will also provide details of assessment and outcomes for the project. The students had to choose materials, minimize production cost, and determine fabrication techniques for the apparatus. Students designed the apparatus using SolidWorks, and SolidWorks Flow Simulation software was used to simulate the swirling pipe flow. Students designed a pipe flow apparatus with static mixers, diffuser, settling chamber, honeycomb, screens and a contraction in order to minimize the disturbance level of the flow entering the pipe section. The pipe had a section that could be rotated in order to study the effects of swirling motion on the stability of pipe flow. Students were involved in the building of the apparatus and they performed pressure drop measurements and determined friction factors.

This paper summarizes the results obtained in the use of plastisols of vinyl chloride homopolymer (PVC), obtained by the process of emulsion polymerization, as thermoplastic matrix in the production of composite pipes and in pipe repairing. Two processing techniques commonly used with thermosetting matrices were studied: filament winding and hand lay-up. The produced composite structures of PVC reinforced with glass fibres were subsequently subjected to tests in order to determine their mechanical properties. This paper concludes that it is possible to use the described technique for piping repairing with good results.

Lap joint flanges are also known as Backup flanges, Loose Ring flanges, Loose Hubbed flanges, and Van Stone flanges. Choosing the right flanges for your industrial application is crucial. It entirely depends on the requirement of the intended application. Lap joint flanges are suitable for piping systems, allowing easy disassembly, while rolled angle rings are suitable for structural applications to create curved or rounded shapes within various structures.

Slip-on flange is a popular type of pipe flange designed to accept pipe into the bore/center of the flange for welding around both the Outer Diameter (OD) of the pipe and on the interior side of the connection. You may recognize them: The slip-on flange is a simple and excellent alternative to a weld neck as it does not have a weld bevel, and therefore allows the pipe to be adjusted in length relative to its position of the flange. The bore of the slip on will give ample amount of space for the matching pipe. This allows for enough working space for the welder and fabricator to make the connection.

Texas Flange has served the petrochemical, process, and waterworks industries for over 3 decades.
We provide ANSI, API, and AWWA pipe flanges in carbon steel, stainless steel, alloys, and chrome steel. Styles we offer include Weld Neck, Slip On, Blind, Threaded, Socket Weld, Lap Joint, Orifice Flanges, Ring, and custom flanges in sizes from 1/2″ to 203″.

A water pipe is any pipe or tubes designed to transport and deliver water or treated drinking with appropriate quality, quantity and pressure to consumers. The varieties include large diameter main pipes, which supply entire towns, smaller branch lines that supply a street or group of buildings or small diameter pipes located within individual buildings. This distribution system (underground) is used to describe collectively the facilities used to supply water from its source to the point of usage. Therefore, a leaking in the underground water distribution piping system increases the likelihood of safe water leaving the source or treatment facility becoming contaminated before reaching the consumer. Most importantly, leaking can result in wastage of water which is precious natural resources. Furthermore, they create substantial damage to the transportation system and structure within urban and suburban environments. This paper presents a study on the possibility of using ground penetrating radar (GPR) with frequency of 1GHz to detect pipes and leakages in underground water distribution piping system. Series of laboratory experiment was designed to investigate the capability and efficiency of GPR in detecting underground pipes (metal and PVC) and water leakages. The data was divided into two parts: 1. detecting/ locating underground water pipe, 2. detecting leakage of underground water pipe. Despite its simplicity, the attained data is proved to generate a satisfactory result indicating GPR is capable and efficient, in which it is able to detect the underground pipe and presence of leak of the underground pipe.

This paper discusses the design and development of a compressed natural gas (CNG) vehicle refueling compressor. It describes the concept and design features of a new concept of symmetrical wobble plate compressor. Unlike most existing wobble plate compressors used in the automotive airconditioning systems which are single-staged, the proposed compressor is multi-staged due to the very high pressures of compression required. Employing a symmetrical configuration using two sets of identical wobble plates and pistons, this new design is expected to give a better performance in terms of noise, vibration, capacity and mechanical efficiency. The development of the compressor started with a study on the requirements and technical specifications. Product architecture was then established according to the functional components of the compressor, with a schematic breakdown that represents the operation of the compressor. Concept development was performed to optimally select the number of stages of compression for the proposed configuration and specifications, and other concepts of systems, e.g. cooling system, anti-rotating mechanism, lubrication system, driver system and piping work. The detail design with analyses of thermodynamics, kinematics and dynamics, stressing, lubrication, etc, was then carried out using both theoretical and computational approaches in order to refine and optimise the geometries and dimensions of components before the fabrication of the prototype. The major outcome of this compressor development exercise is the delivery of a production-ready compressor design with a prototype that has successfully passed all the performance tests.

Fire pumping systems are often used in most buildings for firefighting, whether they are residential, commercial, industrial or of any other kind. Such systems are responsible for the water flow and pressure necessary for manual or automatic devices designed to build safety. Therefore, ensuring their availability when an unexpected fire event occurs is very critical. But due to the presence of dissolved oxygen in the water-filled in the pipes, corrosion takes place at some point in time. This will lead to several types of failures in the system if the system is not properly designed with the right material for the environmental conditions and water quality, which in turn will render the system ineffective. This paper discusses the reasons for corrosion in the piping of fire sprinkler systems and their mitigation.

Canntaireachd (pronounced ‘counter-achk’), Gaelic for ‘chanting’, is a complex oral notation used by Scottish pipers for centuries to teach repertoire and performance style in the courtly, ceremonial ceòl mór idiom. Its popular historiography since the 19th century suggests it was fixed and highly formulaic in structure and therefore formal (as befitting its connection to ceòl mór), its use the preserve of the studied elite. However, field recordings of pipers and other tradition-bearers collected and archived since the 1950s in the School of Scottish Studies present a vast trove of evidence suggesting that canntaireachd as a living, vocal medium was (and remains) a dynamic and flexible tool, adapted and refined to personal tastes by each musician; and that it was (is) widely used as well in the transmission of the vernacular ceòl beag idiom - pipe music for dancing and marching. In this paper, I offer some remarks on the nature of canntaireachd, followed by a review of the role of ...

The radon industry typically uses plastic piping from 2" to 6" in diameter in the installation of active soil depressurization systems (ASD). It is also typical to use 2" by 3" or 3" by 4" aluminum downspout for exterior piping. In a previous paper, (ref I), the exhaust airflow in 87 NJ ASD mitigation systems was measured from a low of 11 ch to a high of 167 ch with a median level Of 70 cfin. Fifty-six percent of these systems had air flows between 40 and 90 cfin. These typical air flows can have a large pipe pressure drop because of the system design that will reduce the systems final effectiveness. Most radon mitigators have little idea how much impact changing the pipe size has on their final system performance or how to calculate the pipe pressure drop. This paper discusses the development of a pipe pressure drop calculation for standard mitigation piping and fittings. The formulas for calculating the pressure drop were obtained from the ASHRAE Hand...

This paper presents new types of mechanical devices, developed by SITON in cooperation with other units in Romania, by means of which to control, limit and damp shocks, vibrations and seismic movements in buildings, equipment and pipe networks. The new devices, called "SERB-devices", can overtake static loads over which dynamic loads may overlap and be damped. The devices allow "cuttingoff" the dynamic action incoming from the environment to the protected systems (building, equipment, pipe network, etc) and the overtaking of shocks and vibrations generated by the systems to protect the environment. The devices may have high relative displacements, with or without elastic reaction force, thus allowing the performance of a good isolation of the components against the dynamic action, also overtaking the displacements due to thermal expansions or support yielding. The devices are made of materials that practically are not affected by the aging phenomenon and relative large temperature variations and may be guaranteed throughout the service-life of each unit, without maintenance or repair. The devices are small in size if compared with the existing ones for similar performances. The radiation resistance capacity is very good and therefore allows their use in nuclear-power plants.

Suatu peralatan kilang minyak mempunyai umur dan batas waktu. Jika dalam perawatan peralatan tidak baik dapat mengakibatkan kerusakan seperti kebocoran pada peralatan kilang. Untuk memenuhi reliability pada peralatan kilang, maka perlu dilakukan perawatan terhadap sistem peralatan tersebut secara bertahap dan berkesinambungan. Pada tugas akhir ini dilakukan penilaian resiko terhadap tingkat kerawanan korosi pada unit CDU IV dan HVU II dengan menggunakan pemetaaan korosi. Pemetaan korosi (Corrosion Mapping) adalah suatu pemetaan kecenderungan peralatan dalam instalasi pengolahan minyak tersebut terhadap resiko korosi. Peta korosi yang dituangkan dalam bentuk pewarnaan pada Process Flow Diagram (PFD) dapat digunakan sebagai suatu instrumen untuk memperkirakan tingkat resiko kegagalan peralatan selama beroperasi dalam keadaan normal. Peta korosi peralatan pada unit CDU IV dan HVU II tersebut akan digunakan sebagai masukan dalam pelaksanaan Risk Base Inspection (RBI). Analisa laju koros...

Dalam rangka memenuhi kebutuhan air yang semakin meningkat, tiap tahunnya dan keterbatasan debit sumber air seiring dengan meningkatnya pertumbuhan penduduk yang sebanding dengan peningkatan kebutuhan akan air bersih, maka PDAM Kabupaten Sragen perlu mangkaji kembali kebutuhan air bersih untuk wilayah Kabupaten Sragen. Terutama untuk Kecamatan Sidoharjo pada saat sekarang dan yang akan datang, agar kebutuhan air bersih Kecamatan Sidoharjo dapat terpenuhi. Penelitian ini, menggunakan metode Deskriptif Kuantitatif dengan data antara lain jumlah penduduk Kecamatan Sidoharjo dari tahun 2013-2019, data pelanggan aktif PDAM Sragen unit Sidoharjo tahun 2013-2019. Tujuannya adalah untuk mengetahui kebutuhan air bersih dan kapasitas reservoir saat ini dan melakukan prediksi kebutuhan air bersih dan kapasitas reservoir pada tahun 2030. Kebutuhan air bersih daerah pelayanan unit Sidoharjo saat ini menurut jumlah masing-masing pelanggan adalah 23,774 liter/detik, sedangkan kebutuhan air bersih ...

Pressure vessel and piping systems are widely used throughout industry and research laboratories and contain a very large concentration of energy, and yet, despite the fact that their design and installation comply with federal, state and local regulations and recognized industrial standards, there continue to be serious pressure equipment failures. There are many reasons for pressure equipment failure: degradation and

A 6000 m solar pond was constructed at Bhuj in India in the premises of a milk processing dairy plant to supply process heat and demonstrate the technical and economic viability of solar pond technology in the Indian context. An inexpensive lining scheme, consisting of alternating layers of clay and LDPE (low density polyethylene) combination was used for lining the pond. The pond attained a maximum temperature of 99.88C under stagnation in May 1991 but developed leakage soon after. A failure analysis that was carried out subsequently indicated that the leakage was caused by the combination of high stagnation temperature and large air pockets below the liner. The lining scheme was redesigned and the pond re-established in June 1993.

Entre los años 2006 y 2010, el cáncer de próstata (CaP) fue el más diagnosticado en varones de Mendoza según el Registro Provincial de Tumores (2.115 casos), mientras que en Argentina es el segundo más diagnosticado (44,1%) al igual que en el mundo (31,1%). Aun habiendo disminuido su morbi-mortalidad, el CaP sigue siendo la segunda causa de muerte en varones mayores de 50 años. Un 80% de los cánceres se relacionan con factores exógenos y un 35% con hábitos alimentarios. La obesidad podría influenciar la carcinogénesis prostática mediante una mayor aromatización de andrógenos, alteración de la secreción de adipoquinas, un aumento de citoquinas proinflamatorias, síndrome metabólico coexistente, excesiva ingesta de grasas saturadas, e interfiriendo en métodos diagnósticos. Por ello, en este estudio se analizaron los factores ambientales, metabólicos, hormonales y nutricionales relacionados con enfermedades prostáticas en varones de la provincia de Mendoza. La muestra estuvo constituida por 172 voluntarios con edades comprendidas entre 40 y 80 años, quienes fueron reclutados a partir de una consulta urológica. En ella se efectúo una historia clínica, tacto rectal y cuestionario de síntomas prostáticos IPSS. Se les realizó análisis bioquímico en ayunas que incluyó glucemia, insulinemia, ácido úrico, triglicéridos, colesterol total, colesterol LDL, colesterol HDL y Antígeno Prostático Específico (PSA). Además, se efectuó una evaluación nutricional que incluyó antropometría (determinación de peso, talla, circunferencias de cintura y cadera, medición de pliegues cutáneos para la estimación de la masa corporal grasa) y estimación del consumo de nutrientes y alimentos a través de cuestionario de frecuencia de consumo y recordatorio de alimentos de 24 horas. A partir de los datos obtenidos, se observó que el 14,2% fueron individuos sanos, mientras que el 83% de los pacientes tenían Hiperplasia Benigna Prostática (HBP) y solo el 2,8% CaP. Asimismo el tacto rectal fue normal en el 90,2% de los voluntarios. A nivel nutricional, 13,7% contaban con un IMC menor a 25 kg/m2 (normal), mientras que el 53% tenía entre 26-30 kg/m2 (sobrepeso); el 23,8% entre 31-35 kg/m2 (obesidad I) y el 9,5% mayor a 36 kg/m2 (obesidad II y III). Por otro lado, se analizaron las relaciones entre la presencia de patologías prostáticas o sus sintomatologías y factores agrupados en dos categorías: bioquímicos y nutricionales. De esta manera, se encontró una correlación negativa entre los niveles de PSA y el consumo de licopeno (r =-0,289; p < 0,001) en los voluntarios sin patología maligna. La correlación negativa entre el PSA y el consumo de licopeno, aunque débil, evidencia la protección que confiere este compuesto frente a las patologías prostáticas. Este fenómeno suele presentarse en estados inflamatorios crónicos como la obesidad, por lo que un consumo elevado de este carotenoide de vegetales y frutos de color rojo, podría ejercer un efecto protector ante una posible carcinogénesis prostática. Nuestro laboratorio ha observado importantes propiedades del licopeno en otras investigaciones previas, que dejan en evidencia su importancia como fitoquímico funcional. En un estudio experimental, se apreció una disminución de los valores de PSA en pacientes en riesgo histológico de desarrollar CaP al ser sumplementados con licopeno. En otra investigación, se observó que el licopeno es el único nutriente que favorece directamente el estado antioxidante del organismo, valorado a través del Poder Antioxidante Total. Por último, recientemente se observó que los individuos que consumen licopeno periódicamente muestran un menor estado inflamatorio valorado a través de la Proteína C Reactiva que quienes no consumen dicho carotenoide. Futuras investigaciones son necesarias para determinar qué otros compuestos o estilos de vida generales se asocian con un menor riesgo de carcinogénesis prostática, así como cuáles marcadores bioquímicos son mejores indicadores de riesgo o progresión del CaP.

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The Indonesian smart hybrid light train is a train under development by the government and will operate in Makassar-Parepare, Indonesia track. The authors conducted a numerical study on CFD to investigate the air flow distribution inside the air conditioning ducting and the air velocity and air temperature distribution on Motor Engine and Compartment (MEC) car to achieve the passenger comfort criteria based on the regulation standard of Indonesia Minister of Transportation Number 69 of 2019. This study was conducted by simulating 5 variations of air barriers height inside the supply ducts. The input of air into the ducting has the parameters of mass flow rate, static temperature, static pressure, and density with the values of 1 kg/s, 20 °C, 1 atm, and 1.2 kg/m 3 , respectively. The simulation results show that variation E is the best design which generated the average air velocity and air temperature distribution in the executive passenger cabin with the values of 0.25 m/s and 21.91 °C, respectively. Meanwhile, the other 4 variations did not satisfy the standard. The results also show that the ducting geometry can accommodate the air temperature difference on the MEC car that does not exceed 1.5 °C and the air supply is sufficient from the air conditioner unit to the driver room.

Subsea Tie-in Spool-pieces, comprising pipe straights and bends, and connection systems are commonly used to absorb the pressure/temperature induced flowline end expansions. Though there is wide experience and established spool design and analysis procedures for moderate water depths, deep-water applications introduce increasing complexity due to the high external pressure. Currently, guidance available for the design of such bends is based on attributing the moment capacity of the straight pipe to a bend with the same crosssection geometry and exposed to the same environmental and functional loading conditions. This paper provides detailed descriptions of finite element (FE) modelling that addresses the interaction of the collapse pressure and bending moment by employing advanced non-linear FE analysis. The model takes into considerations of the mechanical loadings, thermal loadings, external pressure effects and flowline functions using nonlinear material properties. The model has...

Wood Group Kenny has developed an advanced pipe-soil interaction subroutine to accompany the analysis of pipeline lateral buckling and axial walking in Abaqus. The pipesoil interaction subroutine takes into consideration both variations in axial friction and the lateral soil berm formation mechanism in the analysis of lateral buckling and axial walking of pipelines subject to cyclic loading. The lateral soil berm formation scheme accounts for differential berm growth on the soil berm front and rear faces, berm resistance accumulation, mobilization distance and the residual ‘sweep’ friction variation in production operation cycles. The subroutine monitors nodal displacement history around a buckle periphery, and has been shown to simulate realistic, cyclic stress ranges, soil berm breakout mechanism during rare high temperature /pressure loading events and the influence of lateral soil restraint in global pipeline walking studies. Due to the complexity of the berm formation mechanism...

Biologists interested in using radio telemetry to track the movements of birds should concurrently conduct studies to assess potential impacts on study organisms, particularly when monitoring threatened or endangered species. We investigated the effects of traditional and digital very high frequency (VHF) radio transmitters on daily nest survival and chick survival rates of Piping Plovers (Charadrius melodus) along the Atlantic Coast in 2012, 2013, and 2015. We attached 1.0-1.2 g transmitters to 110 plovers and monitored their 160 nest attempts. We also monitored 221 nest attempts by 161 control pairs with no transmitters. There was no evidence that nest or chick survival differed between tagged and control pairs. Transmitters did not seem to adversely impact Piping Plover daily nest and chick survival and are a valuable tool to monitor movements of this threatened species.

Monitoring pipe wall erosion/corrosion thinning rates is an important issue in petrochemical and power generation industries. In this paper, two signal processing techniques are utilized for estimating the thinning rate based on ultrasonic pipe wall thickness data collected over a short period of time. The first is a combination of cross-correlation and polynomial curve fitting and the second is a modelbased estimation (MBE) scheme. These techniques are applied to data collected from an accelerated thinning rate apparatus and both show that they are capable of estimating the thinning rates quickly in short time periods with good accuracy. In laboratory applications, thinning rates as low as 10 µm/year were measured within 15 days with an uncertainty of ±1.5 µm/year by both techniques. Although the MBE technique can yield marginally better accuracy, the greater stability and computational speed of the cross-correlation technique make it the preferred choice for industrial use.

This paper presents an analytical investigation of the structural performance of a pre-stressed, precast concrete beam with steel pipe sleeves. The hybrid precast beam consists of reinforcing steel, a pre-stressing tendon, precast concrete and cast-in-place concrete. Steel sections are installed at both ends of the beam, and steel pipe sleeves are installed at the locations of pipes. The steel pipe sleeves in the precast , prestressed beam allow the installation of piping and facility equipment. A strain-compatibility approach was used to predict the influence of the sleeves and pre-stressing on the structural behavior of the hybrid precast beams. It was found that reinforcing rebar, used to reinforce the sleeve openings for circular steel pipes with a diameter of 125 mm, contribute 20% to the flexural load resisting capacity, suggesting that rebar reinforcement can be considered one of the structural components of the beam. The pre-stressed, precast beam with steel pipe sleeve openings exhibited performance similar to that of beams without openings when the reinforcements placed for the sleeve opening were considered part of the flexural stiffness of the beam.

This paper presents an analytical investigation of the structural performance of a pre-stressed, precast concrete beam with steel pipe sleeves. The hybrid precast beam consists of reinforcing steel, a pre-stressing tendon, precast concrete and cast-in-place concrete. Steel sections are installed at both ends of the beam, and steel pipe sleeves are installed at the locations of pipes. The steel pipe sleeves in the precast , prestressed beam allow the installation of piping and facility equipment. A strain-compatibility approach was used to predict the influence of the sleeves and pre-stressing on the structural behavior of the hybrid precast beams. It was found that reinforcing rebar, used to reinforce the sleeve openings for circular steel pipes with a diameter of 125 mm, contribute 20% to the flexural load resisting capacity, suggesting that rebar reinforcement can be considered one of the structural components of the beam. The pre-stressed, precast beam with steel pipe sleeve openings exhibited performance similar to that of beams without openings when the reinforcements placed for the sleeve opening were considered part of the flexural stiffness of the beam.

The basic objective of this study is to analyze the hazards and operational problems of plastic manufacturing plant and provide some recommendation to operate plant in a hazard free environment. HAZOP technique is used to study the whole process of the unit from the storage Silos (Propylene) to Winding machine (collection point of plastic film). Initially eight (08) nodes were selected and analyzed qualitatively as per process flow diagram (PFD) and piping and instrumentation diagram (P&IDs) of the plant. The analysis includes the deviation of the process parameters from the standard conditions, the causes of the deviation, the resulting consequences, and the existing safety measures and finally recommendations were suggested to avoid the damage and loss to equipment, product and personnel. Result shows 25 causes of deviations of process parameters, 19 consequences out of which 53% of the consequences were related to the product, 42 % were related to the equipment and 5% were related to the surrounding and personnel. Moreover, about 11 different existing safety measures were installed and practiced by the company and 16 recommendations were suggested.

The titanium grade 2 is currently used in high-pressure heat exchanges, piping systems in sea water desalination plants, offshore technology and chemical plants. In many of the applications fatigue and/or creep loading conditions occur. In this paper are presented the results of the mechanical behaviour, low cycle fatigue parameters and fatigue crack propagation at room temperature and at 400°C. The influence of temperature, frequency and the shape of wave loading was studied. The creep behaviour was also studied. Curves of the strain and the stress against the time were obtained to 400°C and 500°C. Also the Larson-Miller parameter was determined. Tests to the creep crack propagation study were carried out. Crack propagation in the creep tests conditions used was not verified.

This paper is an extension of previous work which characterises soil behaviours using the grading entropy diagram. The present work looks at the piping process in granular soils, by considering some new data from flood-protection dikes. The piping process is divided into three parts here: particle movement at the micro scale to segregate free water; sand boil development (which is the initiation of the pipe), and pipe growth. In the first part of the process, which occurs during the rising flood, the increase in shear stress along the dike base may cause segregation of water into micro pipes if the subsoil in the dike base is relatively loose. This occurs at the maximum dike base shear stress level (ratio of shear stress and strength) zone which is close to the toe. In the second part of the process, the shear strain increment causes a sudden, asymmetric slide and cracking of the dike leading to the localized excess pore pressure, liquefaction and the formation of a sand

The Gotvand-Olya Dam is a rock-fill dam, located at Khuzestan province in southwest of Iran. Since the dam is subjected to the daily water level fluctuation, such as rapid drawdown and refill, thus induce a structural impact on the behavior of dam body, it draws many soil engineering concerns. In this paper, seepage analysis of the rock-fill dam was primarily conducted to evaluate the dam safety against the leakage through the dam body. Traditionally, steady-state analysis was employed to investigate the seepage in the dam body, summing that water level is fixed at two cases: high and low water levels. Consequently, it was not able to properly reflect the time-dependent characteristics of seepage phenomena. In this study, seepage analysis was numerically performed using 2-D FEM transient analysis. As a particular boundary condition for an analysis, the water level fluctuation was incorporated to simulate the daily changes. As a result, various seepage phenomena were quantified such as hydraulic gradient, seepage vector and pore water pressure distribution at the corresponding time of interest as the water level rises and recedes. At steady state analysis, the seepage flux at high water level in downstream area was predicted to be 78 l/s. In additions, the seepage flux measured and estimated were both acceptable considering design criteria. The result of this study proves that there is no sign of hazardous sources contributing to the possibility of piping, internal erosion and excess leakage through the dam body.

In Japan, as in other countries, bentonite-based buffer materials are expected to play roles in reducing stress from rock masses and mitigating nuclide migration in the geological disposal of high-level radioactive waste. These roles are achieved by ensuring buffer density and thickness based on the swelling characteristics of clay. However, in practical construction, we should also consider bentonite buffer piping erosion, a phenomenon in which the buffer surface is destroyed by groundwater flowing between the buffer and rock. Such piping erosion may be a serious issue for maintaining an engineered barrier for radioactive waste in the geological system. In this study, the dynamic behaviors of piping erosion were experimentally investigated. In the experiments, 500 mm φ × 600 mm height compacted bentonite specimens were placed in a cylindrical acrylic cell and distilled water was continuously injected at a flow rate of 0.1 L/min from the bottom and the side of the cell. The amount of bentonite that flowed out of the cell was measured by turbidity of the suspended clay in the drainage water. In the results, while the bentonite specimen swelled between about 10 and 20 days and attached to the inside wall of the cell, a dominant flow channel (piping) was observed between the swelled bentonite specimen and the inside wall of the cell. In addition, the relationship between the accumulated amounts of injected water and eroded bentonite showed a constant slope on double logarithmic plots. Such behaviors indicate that the shear stress due to water flow locally exceeded the swelled bentonite's shear strength. Furthermore, the slopes were similar to those already reported from a test using a smaller size cell. These results suggest that piping erosion proceeds with a simple regularity and that piping erosion in actual-scale bentonite buffers can be predicted using small-scale data.

In the framework of the INDUSE project, which aims at innovative design method- ologies for the seismic design of industrial equipment and piping systems, case studies have been carried out, performing static and dynamic seismic analyses for two existing steel pipe- line systems including steel supporting structures, situated in an area of moderate seismic ac- tivity: a) A long aboveground 10&quot; ammonia transmission line situated on sleepers with a vertical expansion loop and ending with a fixed point. The system may be typical for long distance above ground pipelines and for pipelines on jetties. b) A 20&quot; gas transmission pipeline at the interface of a buried pipeline section and an above ground piping section, including a branch connection, a vertical spring support structure and a fixed point, e.g. a tank nozzle. This system is typical for many plant piping systems. The calculations were made using commercially available software. Both simplified static equivalent (&#39;u...

Tank discharge gas/vapor flow problems are frequently encountered in both practice and design. To perform this type of design calculation, the first step is to identify whether the flow is choked or not through a trial-and-error solution of an equation for adiabatic flow with friction from a reservoir through a pipe. Developing a direct method without any trial-and-error to identify a choking condition would be helpful for expediting the flow calculations. This paper presents an easy and quick method to identify the choking of gas flow for an emergency relief system consisting of a rupture disk and vent piping. This greatly simplifies the design calculations. The proposed method for validating the venting adequacy of existing ERS circumvents the iteration calculation and the use of Lapple charts. Three case studies for the design of vent piping for rupture disks support the proposed method.

Gasket is one of important part in piping system to prevent leakage, especially in connection between pipes. The purpose of this study was to determine the optimal design on C profile rubber gasket based on contact width considering contact stress. Design parameter in this study were lips thickness (t)=

One of the major problems in modern gas compressing stations is related to surge control of compression system with multi-compressor. Due to the coupled system dynamics, standard controllers can interfere with each unit′s performance. This article introduces a new robust decentralized model predictive control (MPC) scheme for a team of cooperating compressors. In the decentralized control strategy, the integration of H∞ control scheme into a robust tube MPC algorithm is used to solve the surge problem of a multi-compressor dynamical process subject to constraints in a computation efficient way. Nonlinear dynamic for each compressor that contains acoustic of compressor system is considered and brings up the effects of the station's piping system on the compressor surge Numerical simulations Hashem Imani ABOUT THE AUTHORS Hashem Imani is a graduated Ph.D. in Control and System Engineering and his research interests include Nonlinear Control, MPC and Fiber Optics.

The piping system connected with the shipboard equipment may be subjected to excessive vibration due to harmonic base excitation produced by hydrodynamic force imposed on the propeller blades interacting with the hull and by other sources. Vibration design aspects for shipboard pipework are often ignored, which may cause catastrophic fatigue failures and, consequently, leakage and spillage in the sea environment. Without dedicated design codes, the integrity of shipboard equipment against this environment loading can be ensured by testing as per test standard MIL-STD-167-1A (2005). However, in many cases, testing is not feasible and economically viable. Hence, this study develops an FE-based vibration analysis methodology based on MIL-STD-167-1A, which can be a valuable tool to optimize the testing requirement without compromising the integrity of these piping systems. The simulated model dynamic properties are validated with experimental modal testing and Harmonic response analysis result confirm that a mitigating solution option can be verified by a FE based vibration analysis to mitigate the vibration problem.

Flanged joints are used in high pressure applications such as process piping, pressure vessels, risers, pipelines and subsea production systems. These flanges are subjected to external loads in addition to pressure. A brief description of high pressure flanges standards is given. Design of high pressure flanged joints are covered in many design codes. A review of allowable stresses, load factors for bolting, flanges and bolt preload requirements has been made for the following codes: ASME VIII-2, ASME VIII-3, ASME B31.3 Chapter IX, API 6A, API 6X, API 17D, API 17TR7, API 17TR8, API 17G, EN 1591-1 and NORSOK U-001. This paper also presents analytically based structural load-capacity (ultimate strength) design equations for flanged joints. The design equations are used to calculate rated working pressure and flange-face separation load-capacity of API 6A type 6BX flanges. Future code recommendations for flange design are provided.