Piping

To estimate the risks of dam failure phenomenon, it is necessary to understand this phenomenon and the involved governing factors. Overtopping and piping are the two main reasons of earthdam failures. In the piping context, the piping is determined as a phenomenon which is occurred between two phases, the water liquid and the solid soil. In this investigation, the onset of piping and its development, as well as the movement of water in soil, are numerically approached. In this regard, a one-dimensional numerical model based on the mass-conserving finite-volume method is developed and applied in order to simulate the piping phenomenon in a continuous circular tunnel of given initial length and radius, located between upstream and downstream. The simulation result includes the time-variations of radius along the tunnel until the radius value reaches its critical and the piping phenomenon converts to overtopping.

There is quite frequent requirement to provide load-bearing structures in order to safely access components installed at height. This implies, even for the initial and preliminary analysis activities, the construction of scaffolding or the use of special equipment such as lifting platforms. Therefore, considerations regarding technical times and costs to be incurred are objective and necessary. Nowadays, the technological development of the RPAS (Remotely Piloted Aircraft Systems) allows the effective bypass of the above-mentioned difficulties, allowing the carrying out of various checks useful to formulate a possible following campaign of punctual and localized checks. The small size and the sophisticated handling systems gives the possibility of locating with precision in the space at different heights, even in areas characterized by access difficulties. The on-site activities must be conducted by devices and personnel in possession of appropriate authorizations and certifications.
The objective of this article is to propose basic guidelines for carrying out surveys with the support of RPAS. In particular, the technical considerations to be considered for the choice and characteristics of the device and its accessories as well as the necessary actions such as the preparation of the flight plan, risk assessment and communication to the competent groups.

Piping covers very large part of any process plant. If you look at Oil Exploration platform, Refinery and Petrochemical complex one thing that catches the attention is a complex network of piping. Piping is used to transport various process materials from one equipment to another. But why?

Process Plant is a place where a series of activities performed in particular ordered to convert raw material into a useful product and interconnected pipe and pipe components are used to transport raw material, intermediated product and final product to the desired location. Piping components such Pipe, Elbow, Tee, Reducer, caps, flanges, gasket, and Valves are the basic building of Oil & Gas industries.

Learn about Fundamentals of Pipes, Manufacturing Methods and Inspection & testing.

Reliability centered maintenance (RCM) has a key role in the quality system of thermal power plants. Electricity production is definitely not only production of a product, but also becomes a customer service. Reliability is the top quality tier of this service. Incorporation in the Integrated energy system means fast transformations of organization on all levels. The reliability of modern generation components basically influences the efficiency and capacity of a power plant as a whole. This paper presents the results of RCM practice on Unit Two of The Thermal Power Plant ″Nikola Tesla -B″, 2x600 MW, Yugoslavia. RCM implementation on current problems during exploitation emphasized problems with the boiler tubing system. The methodological approach included outages analyses, marking of the most significant ones, determination of main causes of damage (determination of the material exhaustion state based on expert analyses), application of adequate remaining life assessment methodology and finally the recommendations. Based on these analyses, certain technical solutions were performed and as a result, the mean time between failures of the plant increased, as well as its reliability. According to cost efficiency, RCM methodology presented the most effective cost-benefit method for reliability upgrade.

At the end of 2013, Michael Newton sent me a blog (Newton 2014) that he had written challenging two of my recent papers: an article from last July (Lamb 2013), and another that was available to him before it was published (Lamb 2014).  His comments contest my account of the history and development of the musical form known as the strathspey.  This article is a response, focussing on two lynchpins of the ‘exogenous origin’ argument at the heart of his ‘Rebuttal’ in some detail: 1) that Gaelic social dance and dance-music are a ‘package’ which arrived from elsewhere and 2) that the Scottish Reel developed from a French dance form known as the hay (also hey, haye).  I also examine his assertion that Gaelic mouth music ('puirt-à-beul') cannot pre-date the 18th century due to a lack of noble references in them.

The lubricating oil system is primarily used to lubricate wear surfaces to minimize friction losses, it cools internal engine parts which cannot be directly cooled by the engines' water cooling system and it cleans the engine by flushing away wear particles amongst others. Adequate lubrications require lubricant (oil) with sufficient film strength to withstand bearing pressure and viscosity index low enough to allow adequate flow when subjected to heat. The system consist of the tanks (storage, settling, sump and head), lube-oil pumps, strainers, oil coolers, piping, valves, and fittings, lubricating oil purifier, sub system and condition monitoring devices amongst others. The lubricating oil system for a tug boat whose transmitting power is about 955KW was calculated mathematically to obtain the flow rate of the shaft line bearing cooling oil, stern tube bearing cooling oil, main engine camshaft bearing cooling oil and main engine camshaft bearing cooling oil. Modelled equations were employed to obtain the camshaft lube-oil pump capacity, surface area and storage tank. The cylinder lube-oil storage and density tanks were estimated to be 1m 3 while the transfer pump is calculated to be approximately 0.4m 3 /hr. The various suction and discharge diameters and velocities of pumps in the lubricating oil system were determined; it was observed the suction pipe diameter is always bigger than the discharge pipe diameter while the discharge velocity is higher than the suction velocity for all the pumps including the camshaft lube-oil pump, cylinder oil transfer pump and main lube-oil transfer pump. This is a clear indication that the said design process met the international standard for the design of such a tug boat. Similarly the shaft line bearing cooling oil pipe, piston bearing cooling oil pipe and main engine lube-oil pipe discharge velocities were seen to be at the acceptable limits obeying the classification rules. All designs were done in accordance to the Lloyd's specification rules and regulations for a sea going tug boat.

Similarly to electrical schemas, the control industry (especially the chemical and process industry) describes its plants and their instrumentation by a • P&ID (pronounce P.N.I.D.) (Piping and Instrumentation Diagram), sometimes called P&WD (Piping and wiring diagrams) • The P&ID shows the flows in a plant (in the chemical or process industry) and the corresponding sensors or actors. • At the same time, the P&ID gives a name ("tag") to each sensor and actor, along with additional parameters. • This tag identifies a "point" not only on the screens and controllers, but also on the objects in the field.

According to the conventionally held view, the strathspey or 'strathspey reel' was an eighteenth century innovation instigated by fiddlers of the Speyside region, such as the Browns of Kincardine and the Cummings of Grantown. However, the basic rhythmic characteristics inherent to the strathspey - a series of long and short notes, organised within two or four strong beats per bar - are found in Gaelic songs thought to be much older. Using a range of data from early fiddle collections and transcriptions of twentieth century audio recordings, this paper explores the musical and semantic connections between the strathspey and Gaelic song, suggesting an alternative developmental path for Scotland's national music.

Abstrak— Stainless steel A/SA-312 TP304 merupakan stainless steel seri austenitic yang mengandung 16-20% kromium, 7-22% nikel, dan nitrogen dimana memiliki karakteristik sifat ketahanan korosi yang tinggi dan juga ketangguhan yang baik pada temperatur cryogenic. Material stainless steel seri ini sering dijumpai pada jaringan perpipaan pada kapal LNG carrier dimana pada tahap fabrikasi dan konstruksinya tidak luput dari proses pengelasan. Namun kasus yang ditemui dilapangan adalah menurunnya sifat ketahanan korosi dikarenakan terjadinya chromium depletion paska pengelasan. Oleh karena itu pada setiap pengelasan austenitic stainless steel selalu ditambahkan perlakuan back purging saat proses pengelasan dengan tujuan untuk melindungi daerah root pada pipa dari oksidasi yang dapat menyebabkan terjadinya korosi. Pada penelitian ini dilakukan 2 variabel gas back purging antara gas argon (Ar) dan nitrogen (N) pada pengelasan GTAW austenitic stainless steel A/SA-312 TP304 kemudian dilakukan pengujian hardness, impact, corrosion rate serta analisa terhadap defect atau discontinuity yang mungkin akan terjadi. Hasil dari penelitian ini menunjukkan bahwa variasi gas back purging antara gas argon dan gas nitrogen tidak terlalu signifikan terhadap hardness value, impact value serta discontinuity yang terjadi, tetapi perbedaan variasi gas back purging sangat mempengaruhi corrosion resistant pada hasil logam lasan dimana pemilihan gas back purging terbaik terdapat pada pemilihan gas argon dengan nilai laju korosi sebesar 0.040988 mmpy sedangkan pada pemilihan gas nitrogen sebesar 0.133200 mmpy.

Pipe clamps are often seen as simple elements used for the connection and fixation of pipes and support elements. In case of existing piping, especially in nuclear facilities welding to existing piping is often not acceptable or extremely costly. Friction based supports could offer an alternative approach if their design is proven and the occurring loads can be transferred without sliding or clamp failure. This paper describes the use of friction clamps for the connection of viscous fluid damper to piping systems that are subject to severe seismic loading. A main advantage of these elements is the ease of installation and the omission of any welding. The pipe is connected to the damper only by friction basically using a welded clamp consisting of top and bottom parts. A number of accurately pre-stressed bolts provide the necessary compressive force and friction. For choosing optimal clamp dimensions (thicknesses, widths, bolts number, diameters, etc.) and the proper preload of the bolts a set of design rules has been developed in order to achieve acceptable stress levels in the clamp at maximum design load and sufficient friction capacity in case of torsional loads. The paper also presents the results of structural finite element analysis of several steel pipe clamps used for connection of viscous dampers to pipes with different dimensions. The main purpose of this analysis is to prove that the clamp sustains the maximal seismic force transferred from the damper without sliding between tube and clamp surfaces and without clamp failure. The paper provides the description of the main steps of analysis and the comparison with the proposed analytical method of assessment.

Reliability centered maintenance (RCM) has a key role in the quality system of thermal power plants. Electricity production is definitely not only production of a product, but also becomes a customer service. Reliability is the top quality tier of this service. Incorporation in the Integrated energy system means fast transformations of organization on all levels. The reliability of modern generation components basically influences the efficiency and capacity of a power plant as a whole. This paper presents the results of RCM practice on Unit Two of The Thermal Power Plant ″Nikola Tesla -B″, 2x600 MW, Yugoslavia. RCM implementation on current problems during exploitation emphasized problems with the boiler tubing system. The methodological approach included outages analyses, marking of the most significant ones, determination of main causes of damage (determination of the material exhaustion state based on expert analyses), application of adequate remaining life assessment methodology and finally the recommendations. Based on these analyses, certain technical solutions were performed and as a result, the mean time between failures of the plant increased, as well as its reliability. According to cost efficiency, RCM methodology presented the most effective cost-benefit method for reliability upgrade.

Claims management is one of the most important challenges in mega projects and normally included with many financial losses. Effects of probabilistic claims clearly state a need for a comprehensive model to analyze claim risks in projects. In the present research, list of frequent claims are identified in a piping project (from contractor point of view). Then based on risk types, probabilistic claims are evaluated by questionnaire aimed at calculation of probability percentage and also probability of success. The questionnaires were distributed among experienced managers active in oil and gas piping project. In order to find out reliability of the questionnaire, statistical test was successfully applied. Result of the present study is to quantify claims in implementation phase of piping projects and finally by analyzing cost effects and running claim simulation, practical and useful outcomes including impact of claims on cost success rate of the project successfully obtained.

Recent explorations in canyons of the northern part of the White Bardena have allowed us to study new examples of systems of chasms and caves in clay, with developments of several hundreds of meters and hydrogeological features of interest. The cavities have been formed by piping processes. Its exploration, after a period of short rains, has allowed to appreciate its hydrological functioning and the behaviour of the clays under humid conditions, of a temporary nature, since they are semi-desert zones. The cavities found are described and their main geomorphological features are discussed. The work sheds new light on the processes of karstification in clays.

This paper aims to provide a more comprehensive characterization of piping systems in mountainous areas under a temperate climate using geomorphological mapping and geophysical methods (electrical resistivity to-mography – ERT and ground penetrating radar – GPR). The significance of piping in gully formation and hillslope hydrology has been discussed for many years, and most of the studies are based on surface investigations. However , it seems that most surface investigations underestimate this subsurface process. Therefore, our purpose was to estimate the scale of piping activity based on both surface and subsurface investigations. We used geophysical methods to detect the boundary of lateral water movement fostering pipe development and recognize the internal structure of the underlying materials. The survey was carried out in the Bereźnica Wyżna catchment, in the Bieszczady Mountains. (Eastern Carpathians, Poland), where pipes develop in Cambisols at a mean depth of about 0.7–0.8 m. The geophysical techniques that were used are shown to be successful in identifying pipes. GPR data suggest that the density of piping systems is much larger than that detectible from surface observations alone. Pipe length can be N 6.5–9.2% (maximum = 49%) higher than what surface mapping suggests. Thus, the significance of piping in hillslope hydrology and gully formation can be greater than previously assumed. These results also draw attention to the scale of piping activity in the Carpathians, where this process has been neglected for many years. The ERT profiles reveal areas affected by piping as places of higher resistivity values, which are an effect of a higher content of air-filled pores (due to higher soil porosity, intense biological activity, and well-developed soil structure). In addition, the ERT profiles show that the pipes in the study area develop at the soil–bedrock interface, probably above the layers of shales or mudstones which create a water restrictive layer. Our results illustrate the suitability and limitations of GPR and ERT to study soil piping. In general, geophys-ical surveying is useful for gathering more information on pipe density, potential pipe detection, and recognition of the internal structure of materials underlying the pipes. However, the interpretation of radargrams and ERT profiles should be always accompanied by detailed terrain mapping due to potential disturbances affecting geo-physical profiles.

This paper presents a powerful machine learning (ML) model called isotonic regression to predict the corrosion growth process in the oil and gas pipelines. The paper mainly aims to show the powerfulness of this model in predicting corrosion depth in the pipeline. The isotonic regression model is selected in this study because it is a non-parametric model that can be freely shaped without assuming any shape of target function to overcome the highly stochastic nature of the corrosion growth mechanism. The other reason, the isotonic regression model is also designed to predict the monotonic increasing degradation mechanisms such as corrosion. The paper also evaluates three machine learning models used in regression analysis: linear regression, isotonic regression, and power regression based on the actual corrosion depth data collected from five sensors attached to the studied pipeline. Jupyter notebook is used in the evaluation process of each ML model performance. Four types of prediction accuracy metrics are used to calculate the prediction performance of each ML model, such as mean absolute error (MAE), mean squared error (MSE), root mean square error (RMSE), and R-squared. This paper finds that the isotonic regression model is promising to overcome the complexity issue associated with the corrosion depth prediction application as the corrosion growth nature is associated with high uncertainties, stochastic, and randomness. Finally, this paper recommends utilizing this model by the pipeline operators in the oil refineries in order to have an effective predictive maintenance plan that avoids the need for more complex maintenance activities and maximizes the pipeline's usage.

Salah satu masalah sistem perpipaan adalah rugi aliran (head lossess) akibat penggunaan reducer dan elbow. Kerugian head (head loss) sangat merugikan dalam sistem perpipaan, karena head loss yang besar menyebabkan tekanan fluida menjadi lebih rendah dari yang diharapkan sehingga suplai fluida tidak mencukupi. Tujuan penelitian ini adalah untuk mengetahui jarak pemasangan reducer dan elbow yang optimal untuk mencapai headlosses minimal. Metode yang digunakan adalah true experiment research dengan membuat alat uji headlosses dengan variasi debit air sebesar: 20, 25, dan 30 l/min, serta variasi jarak elbow: 6, 12, 18 cm. Hasil pengambilan data secara eksperimen menunjukkan bahwa pressure drop dan head losses terbesar terjadi pada debit 20 l/min dengan jarak elbow 6 cm, yaitu sebesar 0,207 bar dan 2,115 m. Sedangkan pressure drop dan head losses terendah terjadi pada debit 30 l/min dengan jarak elbow 18 cm, yaitu sebesar 0,057 bar dan 0,580 m.

Hydrogen embrittlement could be one of the several causes of rupture on carbon steel boiler tube. Cracking occurs primarily because of the precipitation of molecular hydrogen along the grain boundary. The result of this process is formation of methane due to reaction of dissolved hydrogen with carbon in the steel. The hydrogen cracks morphology is specific, i.e.significantly different from the cracks affected by the long time or short time overheating. During hydrogen embrittlement decreasing of steel plasticity is taking place. Also the intensive hydrogen decarburization of the waterside surface of the tube is the process which is simultaneously occurs. Deposits, which could be formed on the waterside of the tube, especially in localized area, may have a great influence on a probability of hydrogen precipitation on grain boundaries and cracks appearing. Disturbance of boiling regime as well as departure from nucleate boiling that is taking place in particular area of waterwall tubing has a great influence o heat transfer process as well as on intensity and localization of hydrogen attack process. Some experimental investigation results of failure of boiler water wall tubes made of 0,2 C 0,5 Mn 0,25 Cr steel are presented.

Problem of boiler component erosion is a very complex and present in practically all fossil fuel power plants burning low heating value coals irrespective of their particular design and operating characteristics. Major fly coal erosion accelerating factors are large amounts of abrasive components in the air-coal mixture and its high velocity. In general terms, there is a trend of implementation of appropriate erosion protection in critical place of pulverized boiler coal preparation equipment. In this paper are presented results of erosion tests provided on samples with different erosion protection materials. Erosion damage profiles of different protection materials were investigated and analyzed on tested samples.

New examples of clay cavities are described, explored at the headwaters of the Valfondo Ravine, Wood Hill and central part of Los Sorianos Ravine, in the Black Bardena. The semi-desert region is located in the south of Navarre and it develops systems of cavities in gray clays with levels of limestone of the Tudela Formation, of Miocene age (Tertiary). Around a dendritic network of ravines have been formed cavities by piping processes in dispersive clays rich in sodium salts. The work provides new examples of caves and tunnels that drill the scalloped walls of notched gorges between depressions and gullies, adding data of geomorphological interest.

A s every piper knows, Donald Mac-Donald is the pioneer of our modern method of writing pipe music on the musical stave, but he has many more claims to fame than that. In his day he was the leading pipe maker, a top piper, collector and editor of pipe tunes, and the first to succeed in publishing collections both of piobaireachd and of light music. His book of piobaireachd has recently been edited by us and published by the Piobaireachd Society, 1 and a second volume, based on his unpublished manuscript, is planned to follow soon. 2 Those who have researched the lives and careers of pipers know only too well how difficult a task that is. It sometimes seems especially difficult with Donald MacDonald, who after all was one of the first to emerge into modern times, and who clearly had a great struggle to promote himself. Added to which, his sons, pipers who might have been expected to carry on the family tradition, were all tragically cut off in the prime of life.

Dispersive clays have been identified as soils which highly erosive because they have a higher percentage of dissolve sodium in their pore water than ordinary clays. The dominant sodium ions increase the thickness of the diffused double water layer surrounding the individual clay particles. This causes the repulsive forces to exceed the attractive forces so that the individual clay particles go into suspension in the presence of water. Their detrimental effect on the performance of dams, canals has been recognized. Piping in earth dams which lead to the failure of dams due to the presence of dispersive clays has been identified in Australia, United States, South Africa and many countries throughout the world. This research presented the tests using various available methods to identify the degree of dispersive of embankment material for Duriangkang dam, the first estuary dam in Indonesia. Analyses to the results were also discussed. The decision not to include the suspected dispersive and moderate dispersive clays in the embankment of Duriangkang dam was taken in order to minimize the risk of eroded and piping progress in the dam body.