Special Fittings Research Articles

Numerical simulation of erosion wear and leakage flow field of gas-solid two-phase flow in a T-shaped pipeline

In the process of natural gas transportation in pipeline, because the natural gas contains mud and sand, the pipeline will undergo erosion wear under the impact of gas-solid two-phase flow. Erosion wear seriously reduces the performance of the inner wall of the pipeline, which is not conducive to the stability of the conveying process and the safe operation of the equipment. Among them, the erosion wear of special pipe fittings such as tee pipe and bend pipe are especially serious. In this paper, the erosion of natural gas T-shaped tee pipeline is simulated by FLUENT software, and the erosion wear and fluid-solid coupling analysis are completed. The erosion characteristics of gas-solid two-phase flow under different fluid velocities, different mass flow rates and different particle diameters are studied, and the maximum erosion rates and corresponding variation trends under different influencing factors are obtained. The flow field characteristics of T-shaped pipeline were analyzed based on the small hole leakage model. The characteristics of the leakage flow field were studied from the three aspects of the pressure inside the pipe, the area of the leakage orifice and the shape of the leakage orifice. The experimental platform was built, and the simulation and experimental results were compared and analyzed to verify the correctness of the established model and CFD simulation.

СУЧАСНЕ ОСВІТЛЕННЯ В ДИЗАЙНІ МУЗЕЙНИХ ЕКСПОЗИЦІЙ

In modern design practice lighting plays an important role. Lighting means intensification of visual and psychological effect of museum exposition. Light plays an active role in perception of exhibit, revealing its shape, texture and color. Natural light is used to create a broad background, and artificial – to focus attention on specific information. The best way is the combination of artificial and natural light. This balance is possible due to technological achievement. New ways of lighting create the conditions for better preservation of objects.Lighting techniques give the possibility to make the exposure dynamic, without resorting to mechanical kinematic schemes. Since the motion of light attracts the attention of the viewer more than the movement of objects, this fact became the basis for development of a number of interesting schemes of dynamic lighting. Stands and showcases with dynamic illumination leave a brighter footprint in memory.The choice of the lighting system is closely linked with the architecture of the museum building and with the system of museum lighting (natural, artificial and combined). In this case, it is necessary to take into account the complexity of specifics of the museum exposition – the need to create the best illumination of exhibits and at the same time to protect them from the harmful effects of light rays. Lighting systems are based on the composition and properties of exhibited museum objects and the acceptable level of lighting for various categories of exhibits.Artificial lighting must be carried out mainly by sources of light, whose radiation in the spectrum is close to the daytime. For illumination special lighting fittings, which are usually hidden from visitors (behind suspended ceilings, embedded in furniture or exhibition equipment) should be used.Nowadays there is a wide arsenal of lighting means aimed to increase the visual and psychological effect of museum exposition, various types of lighting fixtures and lamps used to illuminate expositions. Among the lighting products, the leading role belongs to LED technologies. These technologies are characterized by qualities that are decisive in the organization of the museum environment. This is the ability to give white light to each exhibit, high light output at low power consumption, fire safety, the possibility of tape mounting of light sources, the implementation of programmable light scenarios with a change in color gamut. The latest technologies in lighting systems play an important role in design of museum exposition.

特殊継手排水システムにおける誘導サイホン作用に関する研究 大便器・Pトラップ・わんトラップ・逆わんトラップ設置における排水負荷形態による管内圧力と封水の変動

特殊継手排水システムにおける誘導サイホン作用に関する研究 大便器・Pトラップ・わんトラップ・逆わんトラップ設置における排水負荷形態による管内圧力と封水の変動

Issues in Manufacture and Qualification of Specialty Brazed Joints for Nuclear Applications

Nuclear experimental instrumentation frequently includes the usage of thin-walled (metallic sheathed) thermocouples passing through the boundaries of pressure vessels. This is accomplished by sealing the thermocouples by brazing through special design fittings (passages) which are later sealed / welded to the body of the vessel.Two are the challenges to face : (a) the manufacture of the instrumented passage (b) its mandatory qualification, according to relevant standards. Even the brazing qualification standards are more flexible than for welding, the peculiar situation of nuclear instrumentation still needs special consideration and it is not properly covered by the regular standards.The paper describes the experience of the authors in manufacture of the instrumented passages with steel or Inconel sheathed thermocouples, along with some other known projects, in conjunction with applicability of relevant standards: ASME code, AWS standards, national standards. Since it is about pressure vessels, ASME prescriptions are mandatory in Romania; other standards may serve as valuable sources for the “engineering judgment” allowed and recommended by ASME code.The main problem in such specialty brazing qualification is that for some combinations of base metals and filler (imposed by application), one cannot avoid the significant fragilization due to a tremendous increase of hardness in the brazing area. Base material erosion is added and the effect is catastrophic : sectioning the thermocouples at the slightest movement. For example, brazing Inconel thin-walled tubes with BNi-7 is very hard to control – experimental data and images are included in the paper to illustrate this.Therefore, special means must be applied both in fabrication and in qualification, in order to ensure the product is functional and safe, even being fragile. This approach can be found in French design of irradiation devices, being also considered in the French code for design and construction of experimental reactors and irradiation devices. Being known that French experience in this field is vast, their approach makes us confident that our brazing technique is not wrong but the problem is to be solved through ‘smart’ design and specific procedures. Consequently a tentative set of domestic rules for work and qualification is proposed for discussion and further improvement.

A novel instrument for rapid measurement of temperature-dependent thermal properties of conduction-heated food up to 140 °C

Estimating thermal properties for thick or solid foods at temperatures greater than 100 °C is challenging for two reasons: the long time needed to reach a constant temperature, and the pressure needed to be maintained in the sealed container. An instrument (“Thermal Properties Cell”, or “TPCell”) was developed based on a rapid non-isothermal method to estimate the temperature-dependent thermal properties within a range of commercial food processes (20–140 °C). The instrument design consists of a custom sample holder and special fittings to accommodate the heater within a pressurized environment. The total time of the experiment is less than 1min., compared to existing isothermal instruments requiring 5–6 h to cover a similar temperature range. Thermal conductivities of different food materials were estimated for the temperature range of commercial food processes. The novelty of the instrument lies in its ability to analyze transient temperature data using a nonlinear form of the two-dimensional heat conduction equations.

Analytical study of point fixed glass façade systems under monotonic in-plane loading

The point fixed glass façade system is popular and considered a more elegant façade option compared to the framed glass façade system mainly for storefront, walkways and lobby areas in buildings. Point fixed glass façade system is fixed to the support structure using special bolt fittings and structural spider arms. Generally, the racking performance of these systems is not considered at the design stage in low to moderate seismic region and the system may be vulnerable if there is insufficient in-plane drift capacity compared with the demand imposed during earthquakes and wind actions. A unique full-scale in-plane racking laboratory test on a typical point fixed glass façade system was conducted and a maximum drift of 2.1% was measured before catastrophic failure. Non-linear finite element models were then developed and benchmarked against experimental results. The experimental results and finite element analyses indicated that a significant amount of the drift capacity was attributed to the rigid body translation in the façade system connections at the built-in oversize holes provided for construction tolerances. In this article, the laboratory test setup and the experimental results are summarised, and the finite element modelling methodology and non-linear analysis approach undertaken using ANSYS for the experimental test are discussed along with number of parametric studies.

APPLICABILITY OF 110G13P TYPE POWDER STEEL FOR PRODUCTION OF CONSOLIDATION DETAILS OF HIGH PARAMETERS POWER FITTINGS

The special power fittings are one of the basic elements defining reliability of operation of thermal and nuclear power plants which main function consists in ensuring operation of automatic control systems of the power unit parameters by regulation of working environment streams. Wear-resistant welding made by CN-6L electrodes is mainly used now for ensuring operability of sealing surfaces of fittings. Using of Hadfield steel having high resistance to shock abrasive wear as a special material of sealing surfaces of pipeline fittings is of interest. Despite its obvious advantages, Hadfield foundry steel isn't applied in pipeline fittings because of having cracks, foundry defects and big structural heterogeneity. Therefore the possibility of using of powder metallurgy methods for receiving details of sealing of special pipeline fittings on the basis of the 110G13 compositions received by electro-contact sealing and dynamic hot pressing methods is considered in the work. Powder compositions materials based on Hadfield steel with glass component are determined to be perspective for armature engineering using for small details of heavy loaded sealings as their introduction into furnace charge increases leakproofness and provides grindability of products. Technological process of valve saddles of shutoff fittings production by a method of dynamic hot pressing is presented.

CFD Model of an Underfloor Air Cavity Created from Special Fittings and its Verification Using a Laboratory Model

Recently, there has been a tendency of increased complete reconstructions of historical buildings that have not been administered, nor used and have subsequently fallen into disrepair. The acting humidity can be effectively removed, using ventilated floors. The paradox is that these methods have been used for many centuries and until recently, only in laymans terms. The remaining problem involves drafts in air cavities in general. To assess the airflow in the air cavity, recently commonly used CFD simulations can be employed. In this article CFD simulation of underfloor air cavity created by special fittings is verified by means of laboratory experiment.

CFD Proposals for the Layout of Air Vents for Realization of Underfloor Air Cavity Created from Special Fittings

Abstract In basement acting humidity can be removed using ventilated flooring created from special fittings. Particular attention should be paid to the design layout of inlet and outlet of openings. The aim of the correct proposal is the even distribution of air flow over the whole surface of the cavity. To achieve this state and to objective evaluate the air flow in the gaps, which are made up of shaped objects, the work uses CFD simulations. Based on computational simulations, structural designs of underfloor air cavities created using special fittings are designed. As results are the proposals for the layout of air vents for historic buildings for realization in Kosice.

CHARACTERISTICS OF COMBINED DRAINAGE IN THE HOUSE DRAIN OF THE DRAINAGE SYSTEM WITH SPECIAL FITTINGS AND THE APPLICATION OF A PREDICTION TECHNIQUE USING THE PIPE NET WORK MODEL

This study intends to propose a testing method for examining the influence of combined drainage in the house drain on the drainage performance of the stack drainage system which is used for housing complexes. The study also intends to propose a drainage performance prediction technique using the testing method, and subsequently discusses the effectiveness of the testing method and the prediction technique. Subsequent to the previous paper, this paper aims to clarify, using the drainage system with special fittings, the following three points: (1) the aeration property of components of the model, which was proposed in the previous paper for predicting the pressure in the house drain when combined drainage occurs, and evaluate the adaptability of the model, (2) using the model, the prediction of the drainage performance of the house drain which is connected to the stack drainage system and compare acquired values to the SHASE-S206 values, (3) the discussion on the vertical height of the horizontal fixture drain branch against combine drainage, i.e. the horizontal fixture drain branch installable at the lowest floor from the house drain. Based on the above points, this paper also looks at the characteristics of combined drainage in the house drain, which are different when the house drain is on the drainage system with special fittings and when it is on the drainage system with JIS-DT fittings.

特殊継手排水システムを含む排水立て管内平均圧力分布の予測手法 : 超高層住宅における排水立て管内圧力分布に関する研究 その2

This paper studies the prediction method of mean air pressure distribution of drainage stack systems, which includes special drainage fittings. The results of the study are as follows : 1) Clearing the phase of the air pressure distribution of special drainage fitting systems. 2) Verifying the prediction method that was reported by part 1 in special drainage fitting systems and making the margin of application clear. 3) In addition to reinvestigating parameters applied in previous prediction method, the study proposes a new method to easily acquire parameters and offers a wide application range. 4) Proposing a 100 meters class prediction method of mean air pressure by using 30 meters class experiment data.

SQUEEZER: A DEVICE FOR INDIRECT PRESSURE MEASUREMENT IN THIN–WALLED MICROIRRIGATION TUBING –ARS.

A simple device was developed for measuring pressure in thin–walled collapsible emitting hose or tubing in the field. The device, called a “Squeezer,” senses pressure by measuring the force necessary to compress a short section of tubing between two parallel plates to 50% of its original diameter. The force can be measured by either an electronic load cell or a spring balance, and the output, calibrated for a particular size of tubing, read directly in pressure units. The device provides a convenient, non–intrusive and low–cost means for irrigators to assess pressure variations within their microirrigation laterals without installing special fittings or puncturing the tubing.

Partial Cross Sections of Nucleus‐Nucleus Reactions

Spallation cross sections of nucleus-nucleus reactions are calculated by scaling up the proton-nucleus cross sections (with additional fitting factors) using the weak factorization property of fragment production and, with adjusted energy dependence, using the concept of nuclear participants and spectators in nuclear interactions. Special fittings are provided for charge-pickup cross sections. Separate calculations are presented for electromagnetic dissociation cross sections. Elemental and isotopic resolution is comparable to that of the proton-nucleus interactions. Also a brief discussion is presented of the total inelastic cross sections and their energy dependence.

Use of a titanium nitride coating for increasing the operating reliability of pneumatic fittings

ing pressure there is an increase in the forces acting on their individual elements and with an increase in temperature there is a reduction in the strength properties of the material of which they are made (2). As the results of special investigations have shown, 70% of all failures of pneumatic fittings occur as a result of failure of tightness of the valve fit on the seat. To provide optimum operating conditions for a long time the valve and the seat must be made of materials characterized by sufficient strength and withstanding high unit pressures (3). In individual cases in the development of designs of special pneumatic fittings it is not possible to use such widely used steels as 20Kh13, 25KhI7N2, 95Kh18, Kh32N8, and others for production of the valve and the seat because of high unit pressures exceeding the yield or tensile strength of these materials. This problem may be solved as a result of a design modification provid- ing a decrease in the unit load or a softer fit of the valve on the seat but such a solution is not always applicable since it involves complications in the fitting design. A real solution of the problem of increasing the reliability of a pneumatic fitting is impossible without the development of new materials and coatings characterized by higher strength, hardness, erosion resistance, temperature resistance, and corrosion resistance in corrosive media. This work was done for the purpose of increasing the reliability of the gate parts of pneumatic fittings by application of a strengthening coating on the sealing surfaces by the method of vacuum ionic precipitation. The method is based on obtaining a coating by evapora- tion of pure metals in a vacuum and ionization of the flow of metal vapors being precipitated and a reactive gas with the use of an electrical charge. It may be used for obtaining coat- ings both from pure metals and from their compounds in a single cycle. The coatings are characterized by purity and a finely dispersed structure and phase composition. Since this method of application of a strengthening coating is used primarily for the production of cutting tools, development of a method of applying a strengthening coating on the sealing surfaces of the gate of a pneumatic fitting was preceded by an investigation of the physic.mechanical and production properties of the coatings. As a result a method was developed for strengthening the sealing surfaces of the gate of a pneumatic fitting by appli- cation of a titanium nitride coating in an EPN-12 unit.

An Instrumented Triaxial Cell for Cyclic Loading of Clays

Abstract The various features of a novel triaxial cell for research work involving the consolidation and testing of clays under cyclic or static loading are described. Instrumentation is included for the accurate measurement of axial and radial deformations directly on the sample during both consolidation and subsequent cyclic loading. Stiff, sensitive systems have been designed to obtain pore pressure measurements both at the base and near the center of the test specimen. A novel load cell is built in to the loading ram for determination of deviator stress, and a pressure transducer monitors confining stress. Special fittings have been devised to provide long-term lubrication of loading platens. A servo-system permits consolidation under zero radial strain conditions.

AWWA STANDARD for COLD‐APPLIED TAPE COATINGS FOR SPECIAL SECTIONS, CONNECTIONS, AND FITTINGS FOR STEEL WATER PIPELINES

This standard provides for protective exterior coatings that consist of cold‐applied primer and prefabricated tape and their application to special sections, connections, and fittings to be used with underground and underwater steel water pipelines protected with an organic coating.

Improvement of a Continuous-Culture Apparatus for Long-Term Use

A glass and plastic apparatus was designed to meet requirements for continuous culture of cells. Some of the improvements incorporated into this apparatus include an all-glass growth vessel with a self-cleaning bottom, special compression fittings to connect tubing to glass tubing, a removable yield reservoir, and a nonwetting gas exhaust assembly. All portions of the system can be autoclaved for sterilization, and medium bottles and pump lines are replaced aseptically. Images Fig. 1

Improvement of a Continuous-Culture Apparatus for Long-Term Use1

A glass and plastic apparatus was designed to meet requirements for continuous culture of cells. Some of the improvements incorporated into this apparatus include an all-glass growth vessel with a self-cleaning bottom, special compression fittings to connect tubing to glass tubing, a removable yield reservoir, and a nonwetting gas exhaust assembly. All portions of the system can be autoclaved for sterilization, and medium bottles and pump lines are replaced aseptically.

Jungle-Gym Geometry

DID you ever look at something you've looked at time and time again, something utterly familiar to you, something commonplace, and suddenly realize that you haven't the least idea of its construction? That's how I felt when I looked at a jungle gym, plaything of the younger set, and found that I hadn't the foggiest notion of its construction. I knew that it was made by joining lengths of pipes to special fittings, and that kids enjoyed playing on it, but that's about all.

Edificio para Cristalería Española

In the course of a series of lectures on the subject of curtain walls, held at the Higher Technical College of Architecture, in Madrid, the author described his own experience whilst constructing a building (designed by him and by Mr. Manuel Barbero) for the firm Cristaleria Espanola, at San Andres del Palomar, Barcelona. Mr. De la Joya summarised the advantages that foreign experts attribute to curtain walls. These advantages are: less weight of the materials of the enclosing walls; maximum use of the available building surface; cheaper foundations; better building time control; superior quality and accuracy; and greater maintenance facility. The lecturer then explained why, and in what aspects, he was in disagreement with the above supposed advantages. He dealt with these as follows: 1. In terms of present day construction, with concrete blocks and lightweight flooring structures, it is not easy to save much weight, owing to the number of special fittings that are necessary to support and keep the curtain wall in place.—2. Although in theory a. curtain wall may be only 4 or 5 cm thick, the truth is that unless heating or air conditioning is provided on a much larger scale, a special internal protection layer is necessary.—3. It is difficult to reduce the cost of the foundations by fitting curtain walls, and any calculated saving in cost in this aspect is more theoretical than real.—4. Building time estimates usually fail to work out in practice, and in addition to this, workmanship quality is not yet very satisfactory.—5. Curtain walls require periodic overhauls, so that they do not age too rapidly, and in this sense they are no better than traditional walls. The lecturer also made a number of additional points, one of them being that he did not advise the use of curtain walls in Spain (because of the cheapness of brickwalls, the climate, the high cost of air conditioning, etc. He also emphasized how important it is to make a very full and careful study of cost when preparing a project involving curtain walls, in order to evaluate correctly their advantages.