The word ‘hydraulic’ originates from the greek ‘hydor’ (water) and ‘aulos’ (pipe). The term ‘hydraulics’ is applied today to describe the transmission and control of forces and movement by means of a functional fluid. The relevant fluid mechanics theory concerns the study of liquids at rest (hydrostatics), or in motion in relation to confining surfaces or bodies (hydrodynamics). Hydraulic power transmission is the technique of transmitting energy by means of a liquid medium. Liquids utilized for this purpose are termed hydraulic fluids. Use of hydraulics is expanding, and consumption of hydraulic fluids today constitutes a significant part of the world’s total consumption of refined mineral oils, approximately 1 million tons per annum or
around 10%. Mineral oil-based products represent over 90% of all hydraulic media; the remainder are various water-based fluids and synthetic oils. At present the bulk of these products are naturally utilized within the industrialized countries, but the demand for hydraulic fluids is now growing rapidly in the developing countries where vast future potential requirements exist.
Hydraulic fluids find innumerable applications in both static industry and mobile systems outdoors (transport equipment, excavators, bulldozers, etc.). Around 7&80% of the total volume of hydraulic fluids is utilized in static industrial installations. A certain amount of the remaining volume must meet the particularly critical quality requirements of specialized mobile systems in aerospace and military applications.
Hydraulics of pipeline systems
Pipeline systems range from the very simple ones to very large and quite complex ones.
They may be as uncomplicated as a single pipe conveying water from one reservoir to another or they may be as elaborate as an interconnected set of water distribution networks for a major metropolitan area. Individual pipelines may contain any of several kinds of pumps at one end or at an interior point; they may deliver water to or from storage tanks.
A system may consist of a number o sub-networks separated by differing energy lines or pressure levels that serve neighborhoods at different elevations, and some of these may have pressurized tanks so that pumps need not operate continuously. So these conveyance systems will adequately fulfill their intended functions, they may require the inclusion of pressure reducing or pressure sustaining valves. To protect the physical integrity of a pipeline system, there may be a need to install surge control devices, such as surge relief valves, surge tanks, or air-vacuum valves, at various points in the system. How do these systems work? What principles are involved, and how are the systems successfully analyzed and understood? How can the behavior of a preliminary design be evaluated, and how can the design be modified to correct deficiencies? These are some, of many, questions that immediately confront any engineer who is involved in creating the physical infrastructure to satisfy a basic need of mankind: the delivery of water when and
where it is wanted at a price that is affordable. It is the primary objective of these engineers to develop and apply their knowledge to make the system work. Success at this task first requires an adequate knowledge of some fundamental principles of fluid mechanics. Some experience with the solution of hydraulic flow problems is certainly desirable, and it will come with time and effort. These days an understanding of some particular numerical
methods and the ability to implement them on a computer, sometimes for the solution of very large problems, is also a vitally needed skill. Computations associated with engineering practice have changed dramatically in the past quarter century from the estimation of a few key values by using a slide rule to the generation of pages of computer
output that are the result of detailed simulations of system performance in response to various alternative designs, so that the consequences of various ideas can be ascertained quantitatively. The volume of computer output can overwhelm one’s ability to glean the most pertinent information from the numbers. The purpose of this book is to empower the reader with the knowledge, experience, and tools to accomplish this objective.
This book will present to the reader a comprehensive and yet relatively practical study of pipeline hydraulics, with a substantial component being the use of computers for detailed computations that are not practical to perform by hand. The intent of the authors was to create a book, and an accompanying CD, that will serve well any of the following roles:
(1) as a text for senior-level courses for BS students electing to specialize in fluid mechanics, hydraulics, water supply and distribution, and/or water resources; (2) as a text for graduate engineering courses in the same subject areas; (3) to provide instructional material for professional practicing engineers who wish to update their knowledge of specialties associated with the distribution, conveyance, and control of fluids in pipelines; (4) to provide resource material for engineers in governmental agencies at all levels who have responsibilities to design and/or approve plans for pipeline systems; and (5) to provide reference material for consultants who are asked to solve problems, review plans, or suggest project alternatives in the subject areas of this book.
It is with great sense of gratitude and humility I take this blessed moment to offer this Seventh Edition of Piping Handbook. The challenge presented by the success of the Sixth Edition, coupled with our objective to enhance its reference value and widen its scope, motivated us to reach out and draw upon the recognized expertise on piping related topics not covered in the Sixth Edition. In addition, we directed our synergetic efforts to upgrade the existing contents to include the latest advances and developments in the field of piping and related technologies.
Fifteen (15) new chapters and nine (9) new appendixes have been added. These additions accord a unique status to this resource book as it covers piping related topics not covered in any one book. Inclusion of metric and/or SI units along with US customary units is intended to accommodate the growing needs of the shrinking world and the realities of the international market.We have maintained the familiar and easy to use format of the Sixth Edition.
I consider myself fortunate to have the opportunity to associate and work with renowned and recognized specialists and leaders whose contributions are not limited to this Piping Handbook, but go far beyond. For me it has been a rewarding and
enlightening experience. I find myself humbled by depth of their knowledge, practical experience, and professional achievements. These distinguished contributors have offered the sum total of their know how in the form of guidance, cautions,
prohibitions, recommendations, practical illustrations, and examples, which should be used prudently with due consideration for application requirements. The strength, authenticity, and utility of this reference book lie in the wide spread diversity of their expertise and unity of their professionalism. Based upon the feedback received over the past seven years from the users of the Sixth Edition of this handbook, I feel honored to express my and users gratitude to all the contributors for their commitment to their profession and their higher goal of helping others. They have made the difference. Their spirit of giving back has not only continued, but has brought in new contributors to expand the scope and enhance the utility of this handbook. I feel confident that all the contributors shall enjoy the professional satisfaction and the gratitude of users of this handbook. The selfless efforts of all the reviewers listed in the Honors List are of great significance in making improvements in presentation of the subject matter. The extent of their experience, knowledge, and an insight of topics has been instrumental in extracting the best out of contributors and upgrading the contents of this handbook.
The contributors and reviewers have earned a distinguished status. I salute their commitment; admire their efforts; respect their professionalism; and applaud their achievements. I want to recognize their perseverance, dedication, hard work and sincerity of their commitment in spite of increasing demands on their time.
Once more, the dubious honor of writing a preface has been bestowed upon me by my three co-editors. And while they are perfectly willing to share the pluses and minuses of collective editorship, they refused to engage in collective “prefaceship,” if I may be allowed to coin a word. At best, they reserved for themselves the right of looking over my shoulder and criticizing the spirit of levity with which I chose to approach the task for which they had unanimously volunteered me. I should add parenthetically that the preface of the first edition (which you can read on the following pages) is actually my fourth draft; the first three were judged too irreverent by my co-editors. (I have preserved these first three drafts
for whoever inherits my collection of unpublished material.) Assuming that my co-editors are more charitable this time, or alternately that our publisher is pressed for time, what follows (if not what precedes) will appear more or less as written.
First of all, we would like to assure the readers of this second edition of the Pump Handbook that it is not merely a slightly warmed-over version of the first edition, with such errata as we have spotted corrected and with a few insignificant changes and additions. Actually, the task of rewriting and editing the material in a form that would correspond to what was planned for this second edition proved to be a monumental, not to say awesome, undertaking.
To begin with, in concert with the publishers, it was decided that all data given here would appear in both USCS and SI units. This was not as simple a task as it may appear, for the reason that “absolute” pure SI units do not lend themselves well to the scale of numbers generally encountered in industrial processes. To give but one example, the pascal, which is the SI unit of pressure, corresponds to 0.000145 lb/in2, and even the kilopascal is only 0.145 lb/in2. Although this might be a reasonably satisfactory unit for scientific work, the case is hardly such for centrifugal pumps used in everyday life.
Pumping station design
The reception of the first edition of this work by the engineering profession has indeed been gratifying. It seems to have become the standard reference for pumping station designers, and many have said it is the only reference they constantly use. In 1989, it received the “Excellence” award from the Professional and Scholarly Publishing Division of the ssociation
of American Publishers. Each year a single engineering book is awarded this signal honor — a sort of Pulitzer Prize for engineering. Matching that high standard with this second edition has been a challenge. Fortunately, most of the coeditors
of the first edition again gave generously of their time, knowledge, and experience. Timothy Thor took the previous draftsman’s place with equal artistry.
Several experienced and competent authors and contributors joined the group to fill the omissions in
the first edition. The absence of Mary Sanks to type and polish the manuscript left a gap that slowed the
work and increased its difficulty. This second edition is an improvement over the previous one in two major ways. First, every chapter has been examined and revised in some degree to reflect the best modern practice. Some changes are subtle — a word here and there, but many chapters were extensively rewritten. Second, a number of subjects, missing
in the first edition, have been added. These include: (1) interviews with operators and supervisors of 15 utilities
(that together manage 2700 pumping stations) to discover how to make operation better and maintenance
easier and less expensive; (2) guidelines for troubleshooting existing vibration problems; (3) a straightforward explanation of how to avoid vibration problems in new stations; (4) objective, site-specific considerations in recommending whether large submersible pumps should be located in wet wells or dry pits; (5) directions for easily removing large submersible
pumps from wet wells; (6) a comparison of lifecycle costs of constant-speed and variable-speed pumping stations; and (7) advice to utilities on how to choose a consulting engineering firm.
The eighth difference between the two editions is the addition of guidelines and worked examples for the design of modern pump intake basins for small to large pumping stations — especially self-cleaning basins for wastewater. In the first edition, wet wells for solidsbearing waters were limited to the few examples of Seattle Metro — now King County (Washington) Department of Metropolitan Services — pumping stations presented in Chapter 17. Other literature contained little of significance about this important subject, so a four-year period of development and research was immediately begun to improve the selfcleaning properties of the trench-type wet well and to develop guidelines for design. As a result, the selfcleaning properties were enhanced manyfold (as much as 50 or more), and the trench-type wet well, previously limited to variable-speed pumping, was adapted to constant-speed pumping — essentially made possible
by the use of the sloping approach pipe described in Chapter 12. The inclusion of the results of this research and development is the most important improvement in the second edition.
Structural Mechanics of Buried Pipes
Buried pipes are an important medium of transportation. Only openchannels are less costly to construct. On the average, pipelines transport over 500 ton-miles of product per gallon of fuel. Gravity systemsrequire no fuel for pumping. Ships transport 250 ton-miles per gallon. Rails transport 125 ton-miles per gallon. Trucks transport 10 ton-miles per gallon. Aircraft transport less than 10 ton-miles per gallon of fuel.
Buried pipelines are less hazardous, and less offensive environmentally than other media oftransportation. Theyproduce less contamination, eliminate evaporation intothe atmosphere, and generally reduce loss and damage to the products that are transported.
The structural mechanics of buried pipes can be complicated — an interaction of soil and pipe each with vastly different properties. Imprecisions in properties of the soil embedment are usually so great that complicated analyses are not justified. This text is a tutorial primer for designers of buried structures — most of whichare pipes. Complicated theories are minimized. Fundamentals of engineering mechanics and basic scientific principles prevail.
“Science is understanding gained by deliberate inquiry.” — Philip Handler
Valve Handbook, Second Edition
By definition, valves are mechanical devices specifically designed to direct, start, stop, mix, or regulate the flow, pressure, or temperature of a process fluid. Valves can be designed to handle either liquid or gas applications.
By nature of their design, function, and application, valves come in a wide variety of styles, sizes, and pressure classes. The smallest industrial valves can weigh as little as 1 lb (0.45 kg) and fit comfortably in
the human hand, while the largest can weigh up to 10 tons (9070 kg) and extend in height to over 24 ft (6.1 m). Industrial process valves can be used in pipeline sizes from 0.5 in [nominal diameter (DN) 15] to
beyond 48 in (DN 1200), although over 90 percent of the valves used in process systems are installed in piping that is 4 in (DN 100) and smaller in size. Valves can be used in pressures from vacuum to over 13,000 psi (897 bar). An example of how process valves can vary in size is shown in Fig. 1.1.
Today’s spectrum of available valves extends from simple water faucets to control valves equipped with microprocessors, which provide single-loop control of the process. The most common types in use today are gate, plug, ball, butterfly, check, pressure-relief, and globe valves.
Valves can be manufactured from a number of materials, with most valves made from steel, iron, plastic, brass, bronze, or a number of special alloys.
Buried Pipe Design
In American cities, piping systems are complex and marvelous. But the average city dweller does not know of, and could not care less about, buried pipes and simply takes them for granted. This person cannot contemplate the consequences if these services were to be disrupted. City managers and pipeline engineers are sobered by the present- day reality of deteriorating pipe systems. The problem is almost overwhelming. Engineers who deal with piping systems will be key in helping to solve this problem. The First (1990) Edition of this book was well received and hopefully has been of some help to the various practitioners who deal with buried piping systems. It is also hoped that this Second Edition will be helpful in designing, installing, replacing, and rehabilitating buried pipe systems.
There has been progress and changes in the 11 years since the First Edition was published. Thus there are many expansions of and additions to the material in this new edition. Most of the material that appeared in 1990 is also included here, resulting in a book almost twice the size. In addition, there have been many small changes, such
as corrections of the errors that were pointed out by readers. For this kind help, I offer my sincere thanks.
Following is a list of the subjects covered in each chapter, with special mention of new material.
Chapter 2, External Loads. Methods are given for the determination of loads that are imposed on buried pipes, along with the various factors that contribute to these loads. The following topics have been added to this Second Edition: minimum soil cover, with a discussion of similitude; soil subsidence; load due to temperature rise; seismic loads; and flotation. Chapter 3, Design of Gravity Flow Pipes. Design methods that are
used to determine an installation design for buried gravity flow pipes are described. Soil types and their uses in pipe embedment and backfill are discussed. Design methods are placed in two general classes, rigid pipe design and flexible pipe design. Pipe performance limits are given, and recommended safety factors are reviewed. The powerful
tool of the finite element method for the design of buried piping systems is discussed.
The following topics have been added: compaction techniques, E´ analysis, parallel pipes and trenches, and analytical methods for predicting performance of buried flexible pipes.
Chapter 4, Design of Pressure Pipes. This chapter deals with the design methods for buried pressure pipe installations. Included in this chapter are specific design techniques for various pressure piping products. Methods for determining internal loads, external loads, and combined loads are given along with design bases.
The following topics have been added: corrected theory for cyclic life of PVC pipe, and strains induced by combined loading in buried pressurized flexible pipe.
Chapter 5, Rigid Pipe Products. This chapter deals with generic rigid pipe products. For each product, selected standards and material properties are listed. The standards are from standards organizations such as the American Water Works Association (AWWA) and American Society for Testing and Materials (ASTM). Actual design examples for the various products are given.
The following topics have been added: the direct method, design strengths for concrete pipe, and SPIDA (soil-pipe interaction design and analysis).
Chapter 6, Steel and Ductile Iron Flexible Pipe Products. This chapter deals with generic steel and ductile iron pipe products. For each product, selected standards and material properties are listed. The standards are from standards organizations such as AWWA and ASTM. Actual design examples for the various products are given. The following topics have been added: three-dimensional FEA modeling of a corrugated steel pipe arch, tests on spiral ribbed steel pipe, test on low-stiffness ribbed steel pipe, and testing of ductile iron pipe. Chapter 7, Plastic Flexible Pipe Products. This chapter deals with generic rigid pipe products. For each product, selected standards and
material properties are listed. The standards are from standards organizations such as AWWA and ASTM. Actual design examples for the various products are given.
The following topics have been added: long-term stress relaxation and strain testing of PVC pipes, frozen-in stresses, cyclic pressures and elevated temperatures, the AWWA study on the use of PVC, long-term ductility of PE, the ESCR and NCTL tests for PE, and full-scale testing of HDPE profile-wall pipes.
Computational Rheology for Pipeline and Annular F|ow
Students of fluid mechanics learn many laws of nature. For example, the Hagen-Poiseuille pipe flow formula “Q = R4p /(8L),” an exact consequence of the Navier-Stokes equations, gives the steady total volume flow rate Q for a fluid with viscosity , flowing under a pressure drop p, in a circular pipe of radius R and length L. Especially significant are its dependencies; that is, doubling the pressure drop doubles the flow rate, doubling viscosity halves the flow rate, and so on. Similar Navier-Stokes solutions are obtained for other engineering applications, which also yield considerable physical insight.
However, the widely studied Navier-Stokes equations apply only to “simple” fluids like air and water, known as “Newtonian” fluids. Fortunately, a large number of practical Newtonian applications deal with important problems, for instance, external flows past airplanes, internal flows within jet engines, and free surface flows about ships, submarines, and offshore platforms. But for wide classes of fluids, unfortunately, the rules of thumb available to Newtonian flows break down, and useful design laws and operational guidelines are lost. For example, in the context of pipe flow, the notion of a “viscosity ” is no longer simple, even when pressure and temperature are fixed: not only does it depend on flow rate, container size and shape, but it also varies throughout the cross-section of the duct. To complicate matters, there are different classes of on-Newtonian fluids, or “rheologies,” e.g., power law, Bingham plastic, Herschel-Bulkley, and literally dozens of “constitutive laws” or stress-strain relationships characterizing different types of emulsions and slurries.
Real flows can be unforgiving. For example, the fluid “seen” by a pipeline during its lifetime changes as produced oil and water fractions and composition change. Even if the rheological model remains the same, simple “flow rate
versus pressure drop” statements are still not possible; for instance, when the “n and k” for a power law fluid changes, the corresponding “Q versus p” 2 Computational Rheology relationship changes. Because typical rate relationships are very typically nonlinear, it is difficult to speculate, for instance, on what pump pressures might
be required to initiate a given start-up flow rate in a stopped pipeline. In most cases, doubling the pressure drop will not double the total flow rate. Non-Newtonian flows are challenging from an analysis viewpoint. Few exact solutions are available, and then, only for simple fluid models and circular pipe cross-sections. But it is not difficult to imagine subsea pipelines blocked by accumulated wax or by hydrate plugs, as shown in Figures 1-1a,b, bundled pipes with debris settlement, as illustrated in Figure 1-1c, or heavily clogged eccentric drillhole annuli, as depicted in Figure 1-1d, requiring analysis for planning or remedial work. For such geometries, there are no solutions.
Figure 1-1. Typical clogged pipe and annular configurations. The severity of many operational problems is worsened by inaccessibility: clogged underwater pipelines and stuck horizontal drillpipe are virtually unreachable from the surface, and remedial efforts must be performed from afar. Economic consequences, e.g., lost production in the case of pipelines, rig rental fees when not “making hole,” are usually costly. These considerations drive the
need for rheological planning early on. For example, “What pump pressures are required in ‘worst case’ flow start-up?” “What flow properties are associated with a given drilling mud, cement, or emulsion?” “How much production is lost for variously shaped plugs and obstructions?” “Can flow blockage be inferred from changes in “Q versus p” data?” “What kinds of annular designs are optimal for heated bundled pipelines, and how are coupled velocity and
temperature fields calculated for such configurations?” “Can advanced simulation algorithms be encoded in real-time control software?”
Estimator’s Piping Man-Hour Manual
Updated with the addition of 26 new tables on pneumatic mechanical instrumentation, this fifth edition is written for the majority of estimators who have not had the advantages of years of experience and/or of being associated with a firm that spends thousandsof dollars for time studies and research analyses. I believe that the book will decrease the chance of errors and help the partially experienced estimator to determine more accurately the actual direct labor cost for the complete fabrication and installation of process piping for a given industrial or chemical plant. This book is strictly for estimating direct labor in man hours only. You will not find any costs for materials, equipment usage, warehousing and storing, fabricating, shop setup, or overhead. These costs can be readily obtained by a good estimator who can visualize and consider job schedule, size, and location. If a material take-off is available, this cost can be obtained from vendors who will furnish the materials. These items must be considered for each individual job. The following direct man hours (or in the case of alloy and nonferrous materials, the percentages) were determined by gathering hundreds of time and method studies coupled with actual cost of various operations, both in the shop and field on many piping jobs located throughout the country, ranging in cost from $1,000,000 to $5,000,000. By carefully analyzing these many reports, I established an average productivity rate of 70%. The man hours or percentages compiled throughout this manual are based on this percentage. I wish to call your attention to the introduction on the following pages entitled “Production and Composite Rate,” which is the key to this method of estimating.
The Human Factor in Estimating
Updated with the addition of 26 new tables on pneumatic mechanical instrumentation, this fifth edition is written for the majority of estimators who have not had the advantages of years of experience and/or of being associated with a firm that spends thousands of dollars for time studies and research analyses. I believe that the book will decrease the chance of errors and help the partially experienced estimator to determine more accurately the actual direct labor cost for the complete fabrication and installation of process piping for a given industrial or chemical plant. This book is strictly for estimating direct labor in man hours only. You will not find any costs for materials, equipment usage, warehousing and storing, fabricating, shop setup, or overhead. These costs can be readily obtained by a good estimator who can visualize and consider job schedule, size, and location. If a material take-off is available, this cost can be obtained from vendors who will furnish the materials. These items must be considered for each individual job. The following direct man hours (or in the case of alloy and nonferrous materials, the percentages) were determined by gathering hundreds of time and method studies coupled with actual cost of various operations, both in the shop and field on many piping jobs located throughout the country, ranging in cost from $1,000,000 to $5,000,000. By carefully analyzing these many reports, I established an average productivity rate of 70%. The man hours or percentages compiled throughout this manual are based on this percentage. I wish to call your attention to the introduction on the following pages entitled “Production and composite rate”
Facility Piping Systems Handbook 2nd Ed.pdf
Codes relating to piping provide specific design criteria such as allowable materials, working stresses, seismic loads, thermal expansion, and other imposed internal or external loads as well as fabrication, installation, and testing for many aspects of a total piping system. Code compliance is mandated by various federal, state, and local agencies that have jurisdiction and enforcement authority. Each code has precisely defined limitations on its jurisdiction. Familiarity with these limitations can be obtained only after a thorough reading of the code. These codes often refer to standards prepared by nationally recognized organizations. The term nationally recognized is defined as a group or organization composed
of a nationwide membership representative of its members’ views. To achieve nationally recognized status, an association must have been in existence for a reasonable period of time, be active in research and other issues relating to its area of
interest, and be generally regarded by its peers to be scientifically accurate. Standards provide specific design criteria and rules for specific components or classes of components such as valves, joints, and fittings. Dimensional standards provide control for components to assure that components supplied by different manufacturers are physically interchangeable. Pressure integrity standards provide performance criteria so that components supplied by different manufacturers will
function and be service rated (pressure and temperature) in a similar manner. Standards compliance is usually required by construction or building codes or purchaser specifications.
In any piping system design, if different code requirements are discovered, the most stringent requirements must be followed. The applicability of various codes and standards must be ascertained before the start of a project, because submission of plans is often required for approval prior to construction and installation of the piping systems. This requires a code search and consultation with the various authorities having jurisdiction. Fire insurance carriers are another consideration in the area of standards. They very often have more restrictive requirements than the building and construction codes that are normally applicable to every project, particularly in the area of water supply storage and distribution for fire protection purposes, which may be combined with the domestic water system.
Nhận link mediafire qua comment : Để lại địa chỉ mail ( tương tự cho các tài liệu khác)