A methodology for flexibility analysis of process piping

Author(s):  
Umer Zahid ◽  
Sohaib Z Khan ◽  
Muhammad A Khan ◽  
Hassan J Bukhari ◽  
Imran Ahmed ◽  
...  

Design of piping system requires a systematic consideration of various factors as addressed by the codes and standards. This research paper aims to provide a method for flexibility analysis of a selected area of process piping at an industrial plant. Analysis is done for the purpose of accommodating a spare heat exchanger in the process layout. The analysis follows a systematic procedure, with preparation of a tentative model of the system on CAESAR II software followed by insertion of different pipe supports. The selection and location of these supports is based on the results obtained from displacement, stress, reaction and equipment nozzle analysis of the piping system. The design is in accordance with ASME B31.3, which is the standard code for process piping. The proposed method can be adapted for piping configuration of any industrial plant. With the provision of a systematic procedure, the method ensures time saving and efficient flexibility analysis of any piping system.

2021 ◽  
Author(s):  
Charles Becht, IV

Fully updated for the 2020 Edition of the ASME B31.3 Code, this fourth edition provides background information, historical perspective, and expert commentary on the ASME B31.3 Code requirements for process piping design and construction. It provides the most complete coverage of the Code that is available today and is packed with additional information useful to those responsible for the design and mechanical integrity of process piping. The author and the primary contributor to the fourth edition, Don Frikken are a long-serving members, and Prior Chairmen, of the ASME B31.3, Process Piping Code committee. Dr. Becht explains the principal intentions of the Code, covering the content of each of the Code's chapters. Book inserts cover special topics such as calculation of refractory lined pipe wall temperature, spring design, design for vibration, welding processes, bonding processes and expansion joint pressure thrust. Appendices in the book include useful information for pressure design and flexibility analysis as well as guidelines for computer flexibility analysis and design of piping systems with expansion joints. From the new designer wanting to known how to size a pipe wall thickness or design a spring to the expert piping engineer wanting to understand some nuance or intent of the code, everyone whose career involves process piping will find this to be a valuable reference.


2005 ◽  
Vol 128 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Charles Becht ◽  
David W. Diehl

Alternative rules for performing flexibility analysis were added, as Appendix P, in ASME B31.3, the Process Piping Code, 2004 edition. These rules are considered to be more comprehensive than before; they were designed around computer flexibility analysis. To determine stress range, the difference in stress states, considering all loads, is computed. This paper describes the new rules, their intent, and provides several example piping stress analyses, comparing the results of an analysis using the Appendix P rules with that using the rules in the base Code.


Author(s):  
Alwyn Kaye

Abstract A suite of High Rate Heavy Vacuum Gas Oil (HVGO) pumps in an operating Upgrader Plant experienced repeated failures; typically, less than 7 weeks. The need for online measuring tools arose that could measure pump and piping system strain changes with dynamic thermal gradients. The challenge was to record the effect on the entirety of pump component alignment and vibration. In current industrial practices no such tools and techniques are directly and comprehensively available for rotary equipment. Strain gauges are not accurate, and cannot provide broader real time strain mapping. Optical metrology can analyze the mechanical properties and behavior of all kinds of materials in various test scenarios. To date such methods are experimental and principally found in advanced application environments. At the time the method was unknown and especially in such a difficult industrial plant. In such a complex and extreme hot and cold operating service warm-up, cooling, with variations in flow and temperature, can directly and dynamically affect strain measurements. It was not certain whether optical meorology measurement techniques would be able to identify and correlate dynamic operating scenarios with the source of the pump and pipe hardware issues experienced in these Heavy Vacuum Gas Oil (HVGO) pump systems. The influence of the casing thickness and stiffness on the resulting vibration characteristics was investigated by using FEA and operational testing and dynamic analysis. Increasing the interface web thickness results in notable reduction in deformation. Comparison of the results of the live testing against the initial design was performed and studied for remedial action. Materials and heat treatment options were also evaluated and reported. The three-dimensional turbulent flow was modelled and analyzed. The application of those tools for this type of problem are described along with the other rigorous techniques employed. The range of tools included modal and vibration analysis, thermography, rotor and shaft dynamics, baseplate, frame, metallurgical analysis and ultimately compared with FEA, pipe stress modelling and strain analysis. This paper should be read in conjunction with PVP 2020-21204; Piping & Equipment Dynamics of High Rate HVGO Pumps.


2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Nikola Jaćimović ◽  
Sondre Luca Helgesen

Abstract ASME B31.3, the leading process piping system design code, has included in its 2018 edition a new procedure for evaluation of high cycle fatigue in process piping systems. As stated in the Appendix W of ASME B31.3-2018, this new procedure is applicable to any load resulting in the stress range in excess of 20.7 MPa (3.0 ksi) and with the total number of cycles exceeding 100,000. However, this new procedure is based on the stress range calculation typical to ASME B31 codes which underestimates the realistic expansion stress range by a factor of ∼2. While the allowable stress range used typically for fatigue evaluation of piping systems is adjusted to take into consideration this fact, the new fatigue design curves seem not to take it into account. Moreover, the applicability of the new design procedure (i.e., welded joint fatigue design curves) to the components which tend to fail away from the bends is questionable. Two examples are presented at the end of the paper in order to substantiate the indicated inconsistencies in the verification philosophy.


Author(s):  
Umer Zahid ◽  
Sohaib Z Khan ◽  
Muhammad A Khan ◽  
Hassan J Bukhari ◽  
Salman Nisar ◽  
...  

Pipeline systems serve a crucial role in an effective transport of fluids to the designated location for medium to long span of distances. Owing to its paramount economic significance, pipeline design field have undergone extensive development over the past few years for enhancing the optimization and transport efficiency. This research paper attempts to propose a methodology for flexibility analysis of pipeline systems through employing contemporary computational tools and practices. A methodical procedure is developed, which involves modeling of the selected pipeline system in CAESAR II followed by the insertion of pipe supports and restraints. The specific location and selection of the inserted supports is based on the results derived from the displacement, stress, reaction, and nozzle analysis of the concerned pipeline system. Emphasis is laid on the compliance of the design features to the leading code of pipeline transportation systems for liquid and slurries, ASME B31.4. The discussed procedure and approach can be successfully adjusted for the analysis of various other types of pipeline system configuration. In addition to the provision of systematic flow in analysis, the method also improves efficient time-saving practices in the pipeline stress analysis.


Author(s):  
Oreste S. Bursi ◽  
Giuseppe Abbiati ◽  
Luca Caracoglia ◽  
Md Shahin Reza

Seismic risk assessment of industrial plants is of paramount importance to ensure adequate design against earthquake hazards. Seismic vulnerability of industrial plant components is often evaluated through a fragility analysis to conform to structural safety requirements. Fragility curves of single components are usually developed by neglecting the effect of actual boundary conditions. Thus, an incorrect evaluation of individual fragility curves can affect the overall fragility curve of a system. This may lead to “erroneous” seismic risk evaluation for a plant in comparison with its real state. Hence, it is important to study the effect of uncertainties, introduced at the boundaries when coupling effects are neglected, on the dynamic characteristics of a system. Along this line, this paper investigates the effects of uncertain boundary conditions on the probability distributions of the dynamic properties of a simple chain-like system with increasing number of degrees of freedom. In order to describe the uncertain boundary condition, a modified version of the well-known β distribution is proposed. Subsequently, the Analytical Moment Expansion (AME) method is employed to estimate the statistical moments of the output random variables as an alternative to more computationally-demanding Monte Carlo simulations. Finally, a preliminary extension of the proposed approach to a realistic piping system connected to a class of broad/slender tanks is discussed.


Author(s):  
Javad Ozmaian ◽  
Amir H. Farzaneh

Nowadays, time saving in piping stress analysis is a major concern among consultant engineering companies in power and process plants. In this paper, we are going to have a quantity review between some important parameters such as sustained, occasional and expanding stresses with total length and nozzle load of a real case according to ASME B31.3. Most of the times, piping stress designers try different and more flexible piping routes completely arbitrary. Longer piping route means greater mass, and it means a big trouble in earthquake time especially for allowable nozzle loading, on the other hand shorter piping route increases thermal nozzle loading and operating stresses. We will try to find a relationship among mentioned parameters to have an optimal piping route in order to save time and material. Finally, different routes will be analyzed using Caesar II to plot related parameters and find optimum criterion.


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