Output
1)Stress of the pipe at various loading condition
2)Load at various supports and restrain
3)Movement of pipe at support location
4)Pipe terminal point loading. In general power plant piping have to comply stipulations of ASME ANSI B 31.1
Inputs
Geometric layout of pipe
Pipe supporting configuration
Pipe diameter and thickness
Pressure inside pipe cold and hot temperature of pipe
Weight of pipe and insulation
Weight of carrying fluid
Pipe material property (young’s modulus, thermal expansion coefficient)
Thrust on pipe due to earthquake
Load of snow on pipe
Any transient loading like steam hammer load
Any other load on the piping
software for pipe stress analysis
There are several software tools available for conducting pipe stress analysis in engineering and design of piping systems. These software packages are designed to assist engineers in evaluating the structural integrity and performance of piping under various loads and conditions. Here are some well-known software options for pipe stress analysis:
CAESAR II: CAESAR II commercial piping analysis software is one of the most widely used pipe stress analysis software packages. It offers a range of features for analyzing pipe stresses, displacements, and support loads. It is known for its user-friendly interface and seamless integration with CAD systems.
AutoPIPE: AutoPIPE, developed by Bentley Systems, is another popular software for pipe stress analysis. It provides a comprehensive suite of tools for performing static and dynamic analyses, as well as assessing the effects of wind, seismic, and other external forces.
Pipe Stress: Pipe Stress is a user-friendly software solution for pipe stress analysis. It offers a range of features for evaluating thermal expansion, deadweight, and other load cases. It is suitable for both small and large-scale projects.
Ansys Mechanical: Ansys is a widely used finite element analysis (FEA) software suite that can be used for pipe stress analysis. Ansys Mechanical offers advanced capabilities for simulating a wide range of structural and thermal behaviors, making it suitable for complex piping systems.
ROHR2: ROHR2 is a German-developed pipe stress analysis software known for its advanced capabilities in analyzing piping systems subjected to high-temperature and high-pressure conditions. It is widely used in the nuclear and power generation industries.
Piper: Piper is a dedicated pipe stress analysis software that focuses on providing a streamlined workflow for pipe stress engineers. It includes features for both static and dynamic analysis, along with support for various industry standards.
NozzlePRO: NozzlePRO, developed by Paulin Research Group, is specialized software for the analysis of nozzles and pressure vessel components. It provides advanced capabilities for assessing local stresses and loads at nozzle connections.
PIPSYS : is an integrated pipe stress analysis module of PLADES 2000
DynPipe: DynPipe is designed for dynamic analysis of piping systems and is particularly suitable for systems with fluid-structure interaction. It can analyze transient conditions, such as water hammer or seismic events.
The choice of software depends on factors such as the complexity of the piping system, industry-specific requirements, and user preferences. It's essential to select the software that best suits your project's needs and to ensure that the chosen software complies with industry standards and codes, such as the ASME B31 piping codes.
Analysis in pipe
1) Some of the pipes are subjected to high pressure and high temperature also pipes carry of the flowing fluid
2) We nee to check and confirm the pipe is not going to fail with these loading.
3) This process of checking the stress developed in the piping due to various loading is called PIPE STRESS ANALYSIS/FLEXIBILITY ANALYSIS
4) In the process of checking of analysis we apply various postulated loading on the pipe and find out the stress resulted from these loading.
5) Then we check with governing codes if those stresses generated are acceptable or not. We check support load & movement for various loading condition.
6) We also find out the pipe growth due to change in temperature and need to keep the movement of pipe within acceptable limits. Pipe stress analysis is an interactive and iterative process, each step is checked
7) If a check fails we have to go back, modify the layout and restart the analysis.
Codes and Standards
In general power plant piping have to comply stipulations of ASME ANSI B 31.1
In India power cycle piping to comply IBR code requirement
Piping stress analysis is conducted in accordance with various industry-specific codes and standards to ensure that piping systems are designed, analyzed, and operated safely and efficiently. The choice of the code and standard depends on the type of piping system, its application, and location. Here are some of the most widely recognized codes and standards for piping stress analysis:
ASME B31 Codes: The American Society of Mechanical Engineers (ASME) has developed a series of codes under the B31 series, each tailored to different types of piping systems. These codes include:
- ASME B31.1: Power Piping
- ASME B31.3: Process Piping
- ASME B31.4: Pipeline Transportation Systems for Liquids and Slurries
- ASME B31.8: Gas Transmission and Distribution Piping Systems
ASME Boiler and Pressure Vessel Code (BPVC): ASME BPVC Section III provides requirements for the design, construction, and analysis of nuclear power plant components, including piping systems.
API Standards: The American Petroleum Institute (API) has developed various standards relevant to piping stress analysis in the oil and gas industry, such as API 570 (Piping Inspection Code) and API 579-1/ASME FFS-1 (Fitness-for-Service Assessment).
ISO 14692: This international standard covers the design and material selection for fiberglass-reinforced plastic (FRP) piping systems used in the chemical process industry.
EN 13480: This European standard provides guidelines for the design and manufacturing of metallic industrial piping systems.
DIN Standards: Germany's DIN (Deutsches Institut für Normung) standards are used in various industries, including piping systems. DIN 2413, for example, provides guidelines for the calculation of pipe dimensions and bending stresses.
BS EN Standards: British Standards (BS) and European Norm (EN) standards are used in Europe for the design and analysis of piping systems. These standards may be used in various industries, including construction, petrochemical, and energy.
AISC: The American Institute of Steel Construction (AISC) standards are used for the design of steel piping systems and pipe supports.
Other Industry-Specific Standards: Various industries, such as the nuclear, chemical, and pharmaceutical industries, have their own specific codes and standards related to piping systems. For example, the NQA-1 standard is used in the nuclear industry.
Local Codes and Regulations: Depending on the geographical location and specific project requirements, local codes, regulations, and standards may need to be adhered to for piping system design and analysis.
When conducting a pipe stress analysis, it is essential to identify the appropriate code or standard that is applicable to the specific project and type of piping system. Compliance with these codes and standards is essential to ensure the safety, reliability, and regulatory compliance of piping systems in various industries.
What is stress analysis in piping
Piping stress analysis, often simply referred to as "pipe stress analysis," is an engineering discipline that involves evaluating the response of a piping system to various loads and conditions to ensure its structural integrity and safe operation. The primary objective of pipe stress analysis is to prevent issues such as excessive stresses, deformation, and failure that can occur due to factors like thermal expansion, pressure, and external forces. Here are the key aspects of piping stress analysis:
Load Evaluation: Pipe stress analysis begins by identifying and evaluating the various loads that can affect a piping system, including internal pressure, thermal expansion and contraction, deadweight (the weight of the pipe and contents), and external forces (e.g., wind, seismic loads, equipment loads).
Stress Calculation: The analysis calculates the internal stresses and strains within the piping components under the influence of these loads. It considers factors like axial, hoop, and radial stresses, as well as von Mises stress.
Stress Limits: Pipe stress analysis compares the calculated stresses with allowable stress limits defined by industry standards and codes, such as those found in the ASME B31 piping codes. Compliance with these limits is crucial for ensuring safety and reliability.
Flexibility Analysis: Part of the analysis involves assessing the flexibility of the piping system, considering factors like pipe support configurations, expansion joints, and anchor points. This ensures that the system can accommodate thermal expansions and contractions while maintaining allowable stress levels.
Stress Intensification Factors (SIFs): Stress intensification factors are calculated at locations where the piping configuration changes shape, such as elbows, tees, and nozzles. These factors help identify areas of high stress concentration and assess potential failure risks.
Load Combinations: Pipe stress analysis considers various load combinations, including the simultaneous action of pressure, thermal, and external loads, to assess the system's response under different operating conditions.
Fatigue Analysis: In some cases, fatigue analysis is performed to evaluate the cumulative damage caused by cyclic loading, such as pressure fluctuations or temperature variations, to prevent fatigue-related failures.
Support and Anchor Design: Based on the analysis results, appropriate pipe supports, anchors, and restraints are designed and specified to limit movements, vibrations, and stresses within acceptable limits.
Piping stress analysis is essential in industries where the integrity and safety of piping systems are critical, such as in oil and gas, petrochemical, power generation, and industrial manufacturing. It ensures that the system can handle the stresses and movements it experiences during operation without compromising safety and performance. Compliance with industry standards and thorough analysis is crucial to successful piping stress analysis.
when is pipe stress analysis required
Pipe stress analysis is required in a number of situations, including:
- New piping systems: Pipe stress analysis is required for all new piping systems to ensure that they can withstand the forces and moments that they will experience during operation.
- Modified piping systems: Pipe stress analysis is required for any piping systems that are modified, such as by adding or removing components or changing the routing of the piping.
- Existing piping systems: Pipe stress analysis may be required for existing piping systems if there is a concern that the piping may be overstressed or if the piping system has been damaged.
In general, pipe stress analysis is required for piping systems that meet the following criteria:
- Operating pressure: The piping system operates at a high pressure, typically greater than 100 psi.
- Operating temperature: The piping system operates at a high temperature, typically greater than 150°F.
- Pipe size: The piping system is large in diameter, typically greater than 4 inches.
- Hazardous fluids: The piping system carries hazardous fluids, such as toxic or flammable fluids.
- Critical applications: The piping system is critical to the operation of a plant or facility, such as a power plant or chemical plant.
Pipe stress analysis is also required for piping systems that are subject to certain dynamic loads, such as seismic loads or wind loads.
Here are some specific examples of when pipe stress analysis is required:
- Piping systems in power plants: The piping systems in power plants are subject to high temperatures and pressures. Pipe stress analysis is required to ensure that the piping systems can withstand these conditions.
- Piping systems in chemical plants: The piping systems in chemical plants often carry hazardous fluids. Pipe stress analysis is required to ensure that the piping systems are safe and reliable.
- Piping systems in offshore oil and gas platforms: The piping systems in offshore oil and gas platforms are subject to a variety of dynamic loads, such as seismic loads and wave loads. Pipe stress analysis is required to ensure that the piping systems can withstand these loads.
If you are unsure whether or not pipe stress analysis is required for a particular piping system, it is always best to consult with a qualified engineer.
How to calculate pipe stress analysis
To calculate pipe stress analysis, you will need to use a specialized software program. These software programs can model the piping system and calculate the forces, moments, stresses, and strains that act on the piping system under various operating conditions.
The following steps are typically involved in calculating pipe stress analysis:
- Model the piping system: The first step is to model the piping system in the software program. This includes modeling the geometry of the piping system, the supports, and the applied loads.
- Select the material properties: The next step is to select the material properties for the piping system. This includes the modulus of elasticity, yield strength, and ultimate strength of the piping material.
- Apply the load cases: The next step is to apply the load cases to the piping system. The load cases should be representative of the operating conditions that the piping system will experience.
- Solve the analysis: The software program will then solve the analysis and calculate the forces, moments, stresses, and strains that act on the piping system.
- Review the results: The final step is to review the results of the analysis and identify any areas of the piping system that may be susceptible to failure.
It is important to note that pipe stress analysis is a complex process and it is important to have a good understanding of the basic concepts and to follow accepted engineering practices when performing these calculations. It is also important to have the appropriate software and training.
Here are some additional tips for calculating pipe stress analysis:
- Make sure to model the piping system accurately. This includes modeling the geometry of the piping system, the supports, and the applied loads correctly.
- Select the material properties for the piping system correctly. This includes the modulus of elasticity, yield strength, and ultimate strength of the piping material.
- Apply the load cases to the piping system that are representative of the operating conditions that the piping system will experience.
- Review the results of the analysis carefully and identify any areas of the piping system that may be susceptible to failure.
If you are unsure about any aspect of pipe stress analysis, it is always best to consult with a qualified engineer.
pipe stress analysis using caesar ii
CAESAR II is a commercial software program that is widely used for pipe stress analysis. It is a powerful tool that can be used to model and analyze piping systems of all sizes and complexities.
To perform pipe stress analysis using CAESAR II, you will need to follow these steps:
- Create a new model: The first step is to create a new model in CAESAR II. This can be done by importing a 3D model of the piping system or by creating a new model from scratch.
- Define the piping system: Once you have created a new model, you will need to define the piping system. This includes defining the geometry of the piping system, the supports, and the applied loads.
- Select the material properties: The next step is to select the material properties for the piping system. This includes the modulus of elasticity, yield strength, and ultimate strength of the piping material.
- Analyze the model: Once you have defined the piping system and selected the material properties, you can analyze the model. CAESAR II will calculate the forces, moments, stresses, and strains that act on the piping system under the applied loads.
- Review the results: The final step is to review the results of the analysis and identify any areas of the piping system that may be susceptible to failure.
Here are some additional tips for using CAESAR II for pipe stress analysis:
- Make sure to model the piping system accurately. This includes modeling the geometry of the piping system, the supports, and the applied loads correctly.
- Select the material properties for the piping system correctly. This includes the modulus of elasticity, yield strength, and ultimate strength of the piping material.
- Apply the load cases to the piping system that are representative of the operating conditions that the piping system will experience.
- Use the built-in features in CAESAR II to check the model for errors and warnings.
- Review the results of the analysis carefully and identify any areas of the piping system that may be susceptible to failure.
If you are unsure about any aspect of using CAESAR II for pipe stress analysis, it is always best to consult with a qualified engineer.
Here are some specific examples of how to perform pipe stress analysis using CAESAR II:
- Model a piping system with a single elbow: To model a piping system with a single elbow, you would first create a new model in CAESAR II. Then, you would define the piping system by adding a pipe element and an elbow element. Next, you would select the material properties for the piping system and apply the appropriate load cases. Finally, you would analyze the model and review the results.
- Model a piping system with multiple elbows: To model a piping system with multiple elbows, you would follow the same steps as above, but you would add multiple elbow elements to the model.
- Model a piping system with a pump: To model a piping system with a pump, you would first create a new model in CAESAR II. Then, you would define the piping system by adding pipe elements, elbow elements, and a pump element. Next, you would select the material properties for the piping system and apply the appropriate load cases. Finally, you would analyze the model and review the results.
CAESAR II is a powerful tool that can be used to model and analyze piping systems of all sizes and complexities. However, it is important to use the software correctly and to follow accepted engineering practices. If you are unsure about any aspect of using CAESAR II for pipe stress analysis, it is always best to consult with a qualified engineer.
pipe stress analysis book
There are a number of good books available on pipe stress analysis. Some of the most popular titles include:
- Pipe Stress Engineering by Liang-Chuan Peng
- Introduction to Pipe Stress Analysis by Sam Kannappan
- Piping Handbook by Mohinder L. Nayyar
- Design of Piping Systems by M. W. Kellogg Company
- Piping and Pipe Support Systems: Design and Engineering by Thomas J. Van Laan
- Piping Stress Handbook by Victor Helguero M.
"Piping Handbook" by Mohinder L. Nayyar: This comprehensive handbook is a valuable resource for engineers and designers in the field of piping and pipeline engineering. It covers pipe stress analysis, design principles, materials, codes, and standards.
"Process Piping: The Complete Guide to ASME B31.3" by Charles Becht IV: This book focuses on ASME B31.3, a widely used code for process piping. It offers practical insights and guidance for pipe stress analysis, design, and compliance with ASME codes.
"Pressure Vessel Design Manual" by Dennis R. Moss and Michael M. Basic: Although primarily focused on pressure vessel design, this manual also covers piping stress analysis as an integral part of pressure vessel design and analysis.
"Pipe Stress Engineering" by Liang-Chuan Peng: This book is a comprehensive guide to pipe stress analysis and provides a practical approach to addressing various challenges in the field. It includes case studies and practical examples.
"Practical Piping Handbook" by James R. Garber: This handbook offers practical insights into piping design and analysis. It covers pipe stress analysis, flexibility analysis, and design considerations in a user-friendly format.
"Guidelines for Pressure Relief and Effluent Handling Systems" by CCPS (Center for Chemical Process Safety): This book, part of the AIChE (American Institute of Chemical Engineers) guidelines series, includes valuable information on the design and analysis of pressure relief and effluent handling systems, which are critical components of piping systems.
"B31.3 Process Piping: Materials and Component Selection" by GCC (GoConsult Consulting): This book provides detailed information on materials selection, pipe components, and design considerations in accordance with ASME B31.3.
These books cover a wide range of topics related to pipe stress analysis, including:
- The basic concepts of pipe stress analysis
- The different types of pipe stress analysis software
- How to perform pipe stress analysis for different types of piping systems
- How to interpret the results of pipe stress analysis
If you are interested in learning more about pipe stress analysis, I recommend that you read one of these books. They will provide you with a good foundation in the subject and help you to develop the skills you need to perform pipe stress analysis for your own projects.
In addition to the books listed above, there are a number of other resources available on pipe stress analysis, including online courses, tutorials, and articles. You can also find a wealth of information on pipe stress analysis forums and discussion boards.