PIPING CALCULATIONS MANUAL PDF

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Piping Calculations Manual. by: E. Shashi Menon, P.E.. Abstract: This on-the-job resource is packed with all the formulas, calculations, and practical tips. Editorial Reviews. From the Back Cover. Publisher's Note: Products downloadd from Third Party sellers are not guaranteed by the publisher for quality. PIPING AND PIPELINE CALCULATIONS MANUAL This page intentionally left blank PIPING AND PIPELINE CALCULATIONS MANUAL DOWNLOAD PDF .


Piping Calculations Manual Pdf

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Piping handbook / [edited by] Mohinder L. Nayyar.—7th ed. p. cm. .. Hicks HANDBOOK OF MECHANICAL ENGINEERING CALCULATIONS. Higgins et al. which coalescence is produced in the preformed tube by manual or automatic. Pressure Drop Calculations. Piping is known. Need pressure drop. (Pump or compressor is not present.) Incompressible Flow a) Isothermal (ρ is constant). Piping Calculations Manual E. Shashi Menon, P.E. SYSTEK Technologies, Inc. McGraw-Hill New York Chicago San Francisco Lisbon London Madrid Mexico.

It is quite handy as one works calculations at the computer to just pop up the conversion program and put in the data and check.

Several documents give detailed information regarding how to convert to metric from U. SP is somewhat I. It has a very good discussion of conversion, the implied precision in conversions, and is written in plain language for users who are somewhat at a loss regarding conversion other than the strictly mathematical multiply-this-by-that chart or calculator. Not all codes lend themselves to metric conversion urgency, so the pace in the various book sections varies according to international usage.

Some are quite local to the United States and therefore lag in conversion. Many of the B16 fittings and flange standards have converted. In most cases the B16 conversions have made the determination that the metric version is a separate standard. This is a direct result of the problems just described. When making a practical conversion some of the dimensions are not directly converted or are rounded, and are in tolerance in a manner that means that a component made from one set of the dimensions might not be within tolerance of the other set of dimensions.

Where that is the case, the standard or code has a paragraph establishing this fact. The paragraph points out that these are two separate sets of dimensions—they are not exact equivalents. Therefore, they must be used independently of the other.

In the flange standards this created a much more mixed set of dimensions. For tolerance and relevant availability the metric version of the flange standards kept U. More is given on this subject later in Part II and the Appendix. In the piping codes themselves B Since many process industries like chemical and petroleum plants have international operations, B It is even mentioned as the normative reference code in the ISO standard. For that reason, it is probably the most advanced in its establishment of a metric version.

The main remaining pieces of the puzzle in the conversion of B It is hoped that they might be available in the version of that code. This is not necessarily a given, as to be included in the code many things need to happen and not all of them have yet happened. However, various committees are working to accomplish this goal. Stress tables create an almost double problem for the codes.

The tables are presented material by material in what is a regular temperature range. Customary Measurement In U. These are in Fahrenheit, and the fact that they do not directly translate to Celsius causes a problem. Also, the stresses are in thousands of psi pressure per square inch and again not evenly translated into MPa, creating another problem.

These two problems make a requirement for a very large amount of interpolation, which in turn has to be checked for accuracy by an independent interpolation. This, coupled with the 16 temperatures and hundreds if not thousands of those interpolations, means a slow process. The notes in the stress tables indicate the methodology that can be used in getting an equivalent stress from the current U.

Where a metric stress is required those notes will be used to establish an allowable stress for the example problems in this book. The code books themselves already establish any changes in metric constants that may be required to complete calculations. The intention is to convert the codes to metric completely.

This of course cannot realistically happen until the United States takes that step. Those who work with automotive equipment might need a new set of metric wrenches to work on newer devices. Likewise, if one is into antique cars, he or she might need an older set of U. Challenges for Converting from One System to the Other One of the vexing problems is when one is doing calculations that include standard elements such as the modulus of elasticity, moment of inertia, section modulus, universal gas constant, and other similar standard elements.

When one is accustomed to working in one system, he or she may not know all of the standard units that are used in the other. This causes some concern when working a particular formula to get the correct answer in a working order of magnitude. Inevitably, the question is: What unit do I use in the other system? One example could be the section modulus, Z in most B31 codes. It is often used in concert with moments and stresses and other calculated parameters.

Not infrequently there is a power or a square root involved. Which values should be used in such calculations? However, here one must be careful because some disciplines I.

Fortunately, the way the world is going, most conversions are from the USC system to the metric. The saving grace in all this is that whichever system you are working in you can calculate the result in it and then compare what you get to the result you get in the system to which you are converting.

This will essentially develop your own conversion factor for that combination of units to which you had converted the components. Here again, Mother Nature has been kind to us even if the measurement gurus have not.

The stress, for instance, is the same order of magnitude no matter which set of units you calculate in. When I was first learning how to do beam calculation, one of the problems given as an exercise was to calculate the size of a ladder rung that would hold a man of a certain weight on a ladder a certain distance wide.

I had to calculate it in both the USC system and what was then the metric system. After the weight was converted to kilograms from pounds, the width from inches to millimeters, the moment of inertias calculated, and so forth, the size of the rung came out 1 inch or very close in USC.

To my, surprise, the rung in millimeters was 25 or very close , because in the calculation we used integer numbers in the weights, widths, stresses, and so forth, so the answers came out in whatever accuracy that the slide rules allowed. Nowadays, the same exercise would most likely give an answer for the rung diameter in several decimal places.

Two lessons were learned. If your math is right you will get the same special diameter and you can call it what you want. Second, unless you are in some high-precision situation, you can pick the nearest standard size that is safe. It is hoped that someday there will only be one set of unit-sized equipment.

However, it is unrealistic to think that all of the older equipment will disappear overnight should that conversion occur.

The calculations will be done in both U. There are some that are self-evident and need not be done in detail. However, there are more materials than that to be considered. The material that the piping will be immersed in is important. In aboveground piping, that is usually just air, and is not always significant.

Even then one has to consider the environment—for example, the humidity levels and whether the location has extreme weather such as temperature and wind.

If the location is earthquake prone, that has bearing on the design calculations and the construction.

Piping Calculations Manual

Buried piping has another set of concerns. One has to know the topography and soil conditions that the pipeline is routed through.

Usually there is need for some kind of corrosion protection. Does the route cross rivers, highways, canyons, or other things that can cause special problems? All these questions must be considered, and they are not usually spelled out in the piping codes. They may be mentioned as things that must be considered; however, there is often little guidance. There is a whole new set of code requirements for offshore and underwater pipelines. The pipeline codes explain those requirements in detail. One also needs to consider the fluid or material that the pipe system will be transporting.

Selection and Use of Pipeline Materials cific requirements in it for sour gas. As mentioned before, B In each of the codes the scope gives some more information regarding these transport materials. It defines four types of fluid: 1. Category D service. These must meet certain requirements and are basically low pressure, not flammable, and not damaging to human tissue. Category M service.

This is the opposite of Category D fluids and therefore must be treated by separate requirements. High-pressure fluids. These are fluids that have extremely high pressures as designated by the owner and have independent requirements. Normal fluid service. This gives a flavor of what the various transport fluids can be.

Selection of Materials By and large what the fluid a project is for comes as a given. The specifier or designer then chooses an appropriate material to handle that fluid under those conditions.

In general, codes do not have within their scopes which material should be used in which fluid service. However, they may limit which materials can be used in certain system operation conditions, like severe cyclic conditions or other effects that must be considered.

Many of these do not give specific ways to make those considerations. Some methods are discussed later in this chapter. At this point, given a fluid and the need to calculate which piping material should be used, there comes a little bit of interaction with regard to sizing the pipe.

This is especially true when there is the opportunity to have more than one operating condition in the life of the system. In those multiple-operation situations, a series of calculations must be made to find the condition that will require the thickest pipe and highest component pressure rating. For instance, it is possible that a lower temperature and a higher coincident pressure may result in use of heavier pipe than a higher temperature and a lower pressure.

This combination may not be I.

Such considerations will be discussed and demonstrated in much more detail in Part II and the Appendix. The sizes required may have an effect on the materials of selection. All components may not be available in materials compatible with pipe materials. This conundrum was common when higher-strength, high-temperature piping was developed in the late s for hightemperature service.

Material to make components out of similar material was not readily available for several years. It is also true that when newer materials are developed the fabrication skills and design concerns take a little time to develop. New techniques are often required for a result in the same net margins one is used to with the older materials.

That and similar problems explain why the adoption of new materials proceeds at a less-than-steady pace. Having explained generically some of the material problems, we can turn our attention to the materials of construction for a pipe system. The expected use of slurries to transport such things as pulverized coal has not materialized.

Hydrogen Piping System—this is a new code. It is in the final stages of first development. It is planned as a three-part code that will include transportation, piping, and distribution. It will also have a general section that will include things that need only be said once for each of the other parts of the code.

A separate section for hydrogen is needed because it has unique properties that affect the materials of construction, and is generally transported at much higher pressures. It also is an odorless highly flammable gas, and as such requires unique safety precautions. A few specialty books have specific uses and are considered to be valuable to more than one code and therefore can be included by reference to that book.

The oldest one is BG, which is currently under review I. Major Codes and Standards because of its age. There was an attempt to add elements from API to make it more universal. It has been determined that that is not as necessary as bringing the existing edition up to date.

It is, among other things, an effort to bring continuity to piping design. It is hoped that this standard will be included by reference in various B31 books. Most of the major books have an appendix stating the I factors to use for certain geometries. These are based on tests on standard components.

As the technology has changed, a need has developed to determine factors for other geometries that are not in these existing appendices. To provide more objective evidence, as allowed, this standard was developed to reflect how the original intensification factors will be developed. The most familiar of those standards would be the following: A similar result occurs with the standard practices that are written by the MSS. They have several, and not all are recognized by the piping codes. Some API standards, such as the flange standard, have been incorporated in the B The calculation requirements of elements like pipe sizing and flow will be introduced in Part II and the Appendix to give readers some insight into how to perform those calculations.

The process of getting started in any piping project is not specifically covered by a specific standard in its entirety. Often there is an interplay between the process engineer and the system or pipe designer as well as the equipment designer. In all engineering situations, economics come into play regarding project initiation.

One must determine, somehow, the most economical throughput, balancing any economies of scale from increased throughput and budget limitations. Then the problem becomes one of larger pipe size versus equipment size to produce the throughput.

These issues are based on equivalent lengths of pipe, pipe size, fluid friction within the pipe, and so forth. Other than a rudimentary discussion and demonstration of the basics of those decisions, much of the detailed analysis lies outside the scope of this book.

It is quite well covered by other disciplines and their literature. It is important for readers to note that while the various codes and standards offer what appear to be different approaches and calculation procedures to arrive at a specific solution, that difference may not be as great as it first appears. A question I have repeatedly asked myself as I complete a particular set of calculations—How does the pipe or component know which code it was built in accordance with?

Mother Nature does not read codes; she just follows her laws. More complete listings of codes relevant to piping and pipelines can be found in the Appendix of this book. The mathematics must be correct, but then the question forces the technical reviewer to face the inherent margin that the particular code he or she is working with has established.

This comes from the inherent risk the fluid, temperature, and pressure offer within the area that would be affected by a failure, as well as the damage to people, property, and systems that a failure due to an incorrect calculation might incur. When you can answer that question in the affirmative, you are willing to stand behind the result of your work. Having met that challenge, we must address the contentious question of the metric system of measurement versus the U.

For that, we move to Chapter 2. Customary Measurement Overview Whenever one writes anything that includes a measurement system in the United States, he or she is confronted with the problem of presenting the data and calculations. This is especially true when writing about codes and standards.

Most U. The metric system itself has several minor variations that relate to the base units of measure.

This will be discussed more thoroughly in the following. The system has evolved to the point that basically only three countries do not use it as their primary measurement system: Myanmar, Liberia, and the United States. The United States has played with converting to the SI system for as long as I have been working in this field, which is a long time.

Americans have not made the leap to make it our primary system. This lack of tenacity in converting to this system is difficult to understand completely. The most plausible argument revolves around the installed base of measurement and a modicum of inertial thought regarding that seemingly inevitable conversion. To those who have worked with the SI system it is immensely preferred in its decimal conversion from larger to smaller units.

Customary Measurement simpler than converting a length measurement from something like 1. Compare that to converting 1 yard, 2 feet, and 6 inches to 66 inches or 5.

On the other side, there is the problem of what you grew up with. It is rather like translating a language that is not your native language. You first have to get the words into some semblance of your native tongue. As one becomes fluent in another language, he or she can begin to think in that language. The generic classification of this problem is hard versus soft conversions. The terms hard conversion and soft conversion refer to approaches you might take when converting an existing dimension from nonmetric units to SI.

When converting a physical object, such as a product, part, or component, from inch-pound to metric measurements, there are two general approaches. First, one can replace the part with one that has an appropriate metric size. This is sometimes called a hard conversion because the part is actually replaced by one of a different size—the actual hardware changes. Alternatively, one can keep the same part, but express its size in metric units.

With pipe, the international community has come to a working solution to this anomaly because comparable SI pipe has different dimensions than does U. An even more difficult problem comes about when one is determining nonproduct-type decisions while making pipe calculations. That is to ask, which is longer? However, for few of us, even those who have worked with but are not I.

We may sense that they are close. In some calculations 5. In others, it may make the difference between meeting or not meeting a certain requirement. This points to another problem in working with things developed in one system as opposed to other systems. As it relates to conversion, there can be many decision-like problems.

This would depend on the criticality of the dimension in the system. Where we are concerned with a dimension that only needs to be within the nearest 1 8 in. The original 5. One would then have to make comparable decisions about the criticality of the dimension.

SI System of Measurement It was previously mentioned that there are several metric systems. Fortunately, they are not as complex as the U. For instance, in distance measurement the name and unit of measure changes with the size of the distance. We have miles, furlongs, chains, yards, feet, inches, and fractions of an inch, all of which can be converted to the other, but not in a linearly logical base 10 fashion as the SI system does. The different systems in metric are centimeter, gram, and second system.

Another is the kilometer, kilogram, and second system. It can be noted that the major difference in the base unit system is a different length, which essentially just changes the prefixes, as the decimal relationship is constant. It is just up from centimeters to kilometers or down from kilometers to centimeters. Meter, the distance unit. Kilogram, the weight and force unit.

Second, the time unit. Interestingly, a second in France is the same as a second in New York. Ampere, the electrical unit. Customary Measurement 5. Kelvin, the temperature unit. Since most of us live and work in the atmosphere, the Celsius measure is more commonly used. But a degree in either is the same; the difference is the 0 reference point. Absolute 0 in Kelvin and in freezing water in Celsius is a difference of some Candela, the measurement of light, or similar to the U.

Mole, basically the measure of atomic weight. The exact definition is different but the use is similar. These, then, are the metric SI system. Converting back and forth between the two systems is at the least time consuming. In the Appendix there is a conversion chart as well as a chart that focuses on the conversion that applies to the type of calculations commonly used in piping.

There is also a chart that lists the common prefixes as one goes up and down in quantity. Many need to be used only rarely, but it is often maddening not to find them at the moment you need them.

It is also good to have a calculator with some of the fundamental conversions built in. Baring that, there are some common conversions that should be committed to memory so one can quickly move from one to the other. For example, there are None of these are accurate beyond the inherent accuracy of the conversion numbers, but they are good rules of thumb or ballpark conversions.

There are several good ones that are free on the Internet. It is quite handy as one works calculations at the computer to just pop up the conversion program and put in the data and check. Several documents give detailed information regarding how to convert to metric from U. SP is somewhat I.

It has a very good discussion of conversion, the implied precision in conversions, and is written in plain language for users who are somewhat at a loss regarding conversion other than the strictly mathematical multiply-this-by-that chart or calculator. Not all codes lend themselves to metric conversion urgency, so the pace in the various book sections varies according to international usage.

Some are quite local to the United States and therefore lag in conversion. Many of the B16 fittings and flange standards have converted. In most cases the B16 conversions have made the determination that the metric version is a separate standard. This is a direct result of the problems just described. When making a practical conversion some of the dimensions are not directly converted or are rounded, and are in tolerance in a manner that means that a component made from one set of the dimensions might not be within tolerance of the other set of dimensions.

Where that is the case, the standard or code has a paragraph establishing this fact. The paragraph points out that these are two separate sets of dimensions—they are not exact equivalents. Therefore, they must be used independently of the other. In the flange standards this created a much more mixed set of dimensions. For tolerance and relevant availability the metric version of the flange standards kept U.

More is given on this subject later in Part II and the Appendix. In the piping codes themselves B Since many process industries like chemical and petroleum plants have international operations, B It is even mentioned as the normative reference code in the ISO standard.

For that reason, it is probably the most advanced in its establishment of a metric version. The main remaining pieces of the puzzle in the conversion of B It is hoped that they might be available in the version of that code.

This is not necessarily a given, as to be included in the code many things need to happen and not all of them have yet happened. However, various committees are working to accomplish this goal. Stress tables create an almost double problem for the codes. The tables are presented material by material in what is a regular temperature range. Customary Measurement In U. These are in Fahrenheit, and the fact that they do not directly translate to Celsius causes a problem.

Also, the stresses are in thousands of psi pressure per square inch and again not evenly translated into MPa, creating another problem. These two problems make a requirement for a very large amount of interpolation, which in turn has to be checked for accuracy by an independent interpolation. This, coupled with the 16 temperatures and hundreds if not thousands of those interpolations, means a slow process.

The notes in the stress tables indicate the methodology that can be used in getting an equivalent stress from the current U. Where a metric stress is required those notes will be used to establish an allowable stress for the example problems in this book. The code books themselves already establish any changes in metric constants that may be required to complete calculations. The intention is to convert the codes to metric completely.

This of course cannot realistically happen until the United States takes that step. Those who work with automotive equipment might need a new set of metric wrenches to work on newer devices.

Likewise, if one is into antique cars, he or she might need an older set of U. When one is accustomed to working in one system, he or she may not know all of the standard units that are used in the other. This causes some concern when working a particular formula to get the correct answer in a working order of magnitude.

Inevitably, the question is: What unit do I use in the other system? One example could be the section modulus, Z in most B31 codes. It is often used in concert with moments and stresses and other calculated parameters. Not infrequently there is a power or a square root involved. Which values should be used in such calculations?

However, here one must be careful because some disciplines I. Fortunately, the way the world is going, most conversions are from the USC system to the metric.

Tools & Media

The saving grace in all this is that whichever system you are working in you can calculate the result in it and then compare what you get to the result you get in the system to which you are converting.

This will essentially develop your own conversion factor for that combination of units to which you had converted the components. Here again, Mother Nature has been kind to us even if the measurement gurus have not. The stress, for instance, is the same order of magnitude no matter which set of units you calculate in. When I was first learning how to do beam calculation, one of the problems given as an exercise was to calculate the size of a ladder rung that would hold a man of a certain weight on a ladder a certain distance wide.

I had to calculate it in both the USC system and what was then the metric system. After the weight was converted to kilograms from pounds, the width from inches to millimeters, the moment of inertias calculated, and so forth, the size of the rung came out 1 inch or very close in USC. To my, surprise, the rung in millimeters was 25 or very close , because in the calculation we used integer numbers in the weights, widths, stresses, and so forth, so the answers came out in whatever accuracy that the slide rules allowed.

Nowadays, the same exercise would most likely give an answer for the rung diameter in several decimal places. Two lessons were learned. If your math is right you will get the same special diameter and you can call it what you want. Second, unless you are in some high-precision situation, you can pick the nearest standard size that is safe.

It is hoped that someday there will only be one set of unit-sized equipment. However, it is unrealistic to think that all of the older equipment will disappear overnight should that conversion occur. The calculations will be done in both U.

There are some that are self-evident and need not be done in detail.

Piping Calculations Manual (Front Cover to 300).pdf

However, there are more materials than that to be considered. The material that the piping will be immersed in is important. In aboveground piping, that is usually just air, and is not always significant. Even then one has to consider the environment—for example, the humidity levels and whether the location has extreme weather such as temperature and wind. If the location is earthquake prone, that has bearing on the design calculations and the construction.

Buried piping has another set of concerns. One has to know the topography and soil conditions that the pipeline is routed through. Usually there is need for some kind of corrosion protection.

Piping Calculations Manual

Does the route cross rivers, highways, canyons, or other things that can cause special problems? All these questions must be considered, and they are not usually spelled out in the piping codes. They may be mentioned as things that must be considered; however, there is often little guidance.

There is a whole new set of code requirements for offshore and underwater pipelines. The pipeline codes explain those requirements in detail. One also needs to consider the fluid or material that the pipe system will be transporting. Selection and Use of Pipeline Materials cific requirements in it for sour gas. As mentioned before, B In each of the codes the scope gives some more information regarding these transport materials. It defines four types of fluid: Category D service. These must meet certain requirements and are basically low pressure, not flammable, and not damaging to human tissue.

Category M service. This is the opposite of Category D fluids and therefore must be treated by separate requirements. High-pressure fluids. These are fluids that have extremely high pressures as designated by the owner and have independent requirements. Normal fluid service. This gives a flavor of what the various transport fluids can be. Selection of Materials By and large what the fluid a project is for comes as a given.

The specifier or designer then chooses an appropriate material to handle that fluid under those conditions. In general, codes do not have within their scopes which material should be used in which fluid service. However, they may limit which materials can be used in certain system operation conditions, like severe cyclic conditions or other effects that must be considered.

Many of these do not give specific ways to make those considerations. Some methods are discussed later in this chapter. At this point, given a fluid and the need to calculate which piping material should be used, there comes a little bit of interaction with regard to sizing the pipe. This is especially true when there is the opportunity to have more than one operating condition in the life of the system. In those multiple-operation situations, a series of calculations must be made to find the condition that will require the thickest pipe and highest component pressure rating.

For instance, it is possible that a lower temperature and a higher coincident pressure may result in use of heavier pipe than a higher temperature and a lower pressure. This combination may not be I. Such considerations will be discussed and demonstrated in much more detail in Part II and the Appendix.

The sizes required may have an effect on the materials of selection. All components may not be available in materials compatible with pipe materials. This conundrum was common when higher-strength, high-temperature piping was developed in the late s for hightemperature service.

Material to make components out of similar material was not readily available for several years. It is also true that when newer materials are developed the fabrication skills and design concerns take a little time to develop. New techniques are often required for a result in the same net margins one is used to with the older materials.

That and similar problems explain why the adoption of new materials proceeds at a less-than-steady pace. Having explained generically some of the material problems, we can turn our attention to the materials of construction for a pipe system. Each code has what is generally called listed materials. These are materials that the various committees have examined and found to be suitable for use in systems for the type of service that that book section is concerned with.

In many instances, it also lists API 5L piping materials. One major exception is boiler external piping, listed in B If standard group A issued a change to their standard, the adopting group B cannot really study it for adoption until after the publication date. So the lag exists quite naturally.

Selection and Use of Pipeline Materials Table 3. Or they might just keep the earlier edition that they had adopted. Because of this inherent lag, standards groups spend a fair amount of effort letting you know which edition of a standard they have accepted is the one that is operative in that code.

Typically, B31 and other standards will list the standard without an edition in the body of their code. Then they will offer an appendix to the code that lists the editions that are currently approved. Every attempt is made to keep the inherent lag in timing to a minimum. In addition to these listed materials, sometimes unlisted materials are accepted with certain limitations. Also, some discuss unknown materials and used or reclaimed materials.

Table 3. Other standards have materials requirements that often point back to ASTM or an acceptable listing in another standard. This helps to eliminate duplication of effort and the lag problem is again minimized. Some standards develop their own materials. Listed and Unlisted Materials The listed materials are those in the B31 books, which list the allowable stresses at various temperatures for the materials that they have listed. Over a wide range of temperatures the yield and ultimate strengths will go down from ambient temperatures.

In addition, at some temperature, time-dependent properties, such as creep and creep rupture, become the controlling factor. To establish the allowable stresses at a specific high temperature could require expensive and time-consuming tests. It uses them to establish the allowable stress tables.

In cases where the material one wants to use in a project is not listed in the particular code, the first step is to determine whether that code allows the use of such a material. Some guidelines of where to look are in Table 3. The nonmathematical part is to select a material that is in a published specification. This is quite probable because of the proliferation of national or regional specifications that for one reason or another have not been recognized by the codes in either direction.

There is progress in the direction of unifying these different specifications, however slow. To be useful, they must specify the chemical, physical, and mechanical properties. They should specify the method of manufacture, heat treat, and quality control. Of course, they also must meet in all other respects the requirements of the code. Measuring mechanical properties at higher temperatures is expensive and can be very time dependent if one is measuring such properties as creep or creep rupture.

The ASME code, recognizing that this process is difficult, developed a trend line concept to avoid requiring such elevated-temperature mechanical tests for each batch of material made, as is required for the room temperature properties. This is called the trend curve ratio method. The method is relatively straightforward. Some of the difficult extended temperature tests have to be made. While as far as is known there is no set number of tests, it stands to reason that there should be more than two I.

Selection and Use of Pipeline Materials data points to ensure that any trend line that is not a straight line will be discovered from the data points. It also stands to reason that the temperature range of the tests should extend to the higher temperature for which the material is used.

This eliminates extrapolating any curve from the data and limits any analysis to interpolation between the extreme data points, which is just good practice. Obviously, if the intended range extends into the creep or creep rupture range, those tests should be run also.

This decision becomes a bit of a judgment call. However, depending on the material, that may not be where those temperature-dependent calls control the decision. So now one has a set of data that includes the property in question at several different temperatures.

For purposes of illustration, we make an example of a set of yield stresses. This is not an actual material but an example. We will call this material Z and the necessary data to establish the trend curve ratio are listed in Table 3. Given these tables, a regression on the temperature versus the computed ratios can then be established. It should be noted that the original data might be in the same degree intervals that the table is intended to be set up in, but in general this is not the case.

Therefore, a set of data that ranges from the room or normal temperature to the highest intended temperature can then allow a regression that is basically interpolative rather than extrapolative.

It is unlikely that the material supplier has test data at the exact temperature at which one is going to use the material. This is accompanied by the general fact that this is a temperature that is usually within the creep range and that yield is Table 3. Yield above that temperature is not as critically needed. Regardless, the regression yields formulas that allow one to predict the yield at any intermediate temperature. For the previously presented data one regression is a third-degree polynomial that has a very high correlation coefficient.

This explanation applies to the method ASME has developed to avoid the requirement for each batch of material to go through extensive hightemperature testing. The temperature values is that room temperature value multiplied by the appropriate temperature, Ry or Rt.

The same general technique is used for both yield and tensile properties. The criteria involve a percentage of creep over a length of time. These have been standardized in ASME as the following values: This can be described as causing a length of material to lengthen by 0.

Obviously this requires many long tests at many temperatures and many stresses. Once again, many stresses at many temperatures are tried until the part breaks or ruptures.

Again, many stresses at many temperatures are tried. These criteria are basically the same over all the ASME codes. The double shot at the rupture criteria 2 and 3 comes about to eliminate any I. Selection and Use of Pipeline Materials possibility of having a test that gives a wide variability of highs and lows.

It is essentially an analogy for having a rather tight standard deviation in the data. One can also assume that there are expedited testing methods for the creep-type tests. A full-length test of , hours would last over 11 years and several different stresses would have to be tested.

Even a full hour test would take over 41 days. The tensile stress has a percentage applied to it that is set, as much as possible, to ensure that the material has some degree of ductility. The main stress factor is yield stress. The percentage of yield that is allowed is dependent on the code section. The creep criteria are included in this survey, and the one that yields the lowest stress is established as the allowable stress at that temperature. This is not true in the books where the applications have a limited range of operating temperatures, mostly in the pipeline systems.

In those, they simply set the specified minimum yield of the material as the base allowable stress. It is noted that the temperature range for pipe containing natural gas, for instance, would be quite small.

On the other hand, that pipeline can go through a wide variety of locations. Stress Criteria for Nonmetals When one comes to nonmetals the presentation of stresses is considerably different. Nonmetals have a much wider set of mechanical properties with which to contend. There are several types of nonmetallics.

Those recognized by the various codes are thermoplastic, laminated reinforced thermosetting resin, filament-wound and centrifugally cast reinforced thermosetting resin and reinforced plastic mortar, concrete pipe, and borosilicate glass.

The allowable stresses are set this way as well. A brief listing of how those tables vary is as follows: It is the most like the metal tables. The laminated reinforced thermosetting pipe table lists an ASTM specification with a note stating the intent is to include all of the possible pipes in that specification.

That specification gives allowable usage information. The filament-wound materials e. The specification itself defines the controlling pressureresisting dimensions and attributes, eliminating the need for any wall thickness calculation.

The borosilicate glass table lists one ASTM specification and an allowable pressure by size of pipe. This is the way ASME has chosen to handle the nonmetal materials that they list.

Those tables do have an unpredictable difference in allowable stress values for common temperature. Like everything in the chapter, they are mandatory to comply with the code once a piping system has been defined by the owner of the system as a high-pressure system. Many times it is asked: What is high pressure?

The general requirements are that it can be anything, with no specific lower or upper limit. It is high pressure only if the owner specifies it as so.

For purposes of writing the chapter the committee used the definition as any pressure and temperature that are in excess of the pressure at that temperature for the material as defined in the ASME B Corrosion and Other Factors A main remaining consideration in material selection is what is called the material deterioration over time, commonly referred to as corrosion allowance.

That corrosion can occur on the outside of the pipe due to the environment the pipe is in, and can come from the inside due to the fluid and the velocity and temperature of that fluid. The amount of corrosion allowance to be allowed is dependent on the rate the corrosion will occur over time and the expected lifetime of the particular system.

The calculation effort, after the corrosion allowance is set, is addressed in Chapter 5 to calculate pressure thickness. Setting that I. Selection and Use of Pipeline Materials allowance is outside the scope of the codes. There is a suggestion in B The Appendix contains a list of common materials from the U. ASTM Book 1. By and large, they are ASTM materials that have been adopted. Some have restrictions on elements like the chemistry, or some other portion of the current ASTM material may be invoked when adopting them.

Those restrictions are noted in the listing. The primary purpose of these materials is for use in the boiler code sections; therefore, they are not treated in this piping-related book more than they have been already.

There are materials standards from other geographical sections of the world. Many of them are similar to ASTM materials, but some are quite different. It appears on cursory examination that often these standards have a greater number of micro-alloyed materials.

He has taught engineering and computer courses, and is also developer and co-author of over a dozen PC software programs for the oil and gas industry. Menon lives in Lake Havasu City, Arizona. This on-the-job resource is packed with all the formulas, calculations, and practical tips necessary to smoothly move gas or liquids through pipes, assess the feasibility of improving existing pipeline performance, or design new systems. Full details. Table of Contents A.

Preface B. About the Author 1. Water Systems Piping 2. Fire Protection Piping Systems 3.This is sometimes called a hard conversion because the part is actually replaced by one of a different size—the actual hardware changes. In all engineering situations, economics come into play regarding project initiation. The CFD simulation is then presented in section 3. When you can answer that question in the affirmative, you are willing to stand behind the result of your work.

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For information about certain cookies used for advertising by third parties, including through cross-device tracking, and to exercise certain choices you may have regarding such cookies, please visit the Digital Advertising Alliance , Digital Advertising Alliance-Canada , Network Advertising Initiative , and the European Interactive Digital Advertising Alliance. That and similar problems explain why the adoption of new materials proceeds at a less-than-steady pace.

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