ASME B31 Research Articles

Case study: Methodology of reinforcement calculation for newly installed pressure vessel in an industry

The project entails the installation of new pressure vessels in a petrochemical industry in Mangaluru to meet the process requirements of the fluid that runs in the unit. This article focuses on the process that led to the effective development of piping between the newly installed pressure vessel and the unit, as per ASME B31.3. The document briefly discusses the stages needed in designing a piping system for newly installed pressure vessels, prominently the reinforcement calculations, which were performed in accordance to ASME section VIII division1.

Analysis of Symmetrical and Nonsymmetrical Vertical Expansion Loop to Increase Flexibility And Reduce Pipe Stress Based On ASME B31.3

Thepiping system is a medium used to convey, distribute, mix, separate, discharge, meter, control or snub fluid flows, and transmit a fluid pressure. The piping system design will have stresses due to thermal and pressure effect. The thermal effect induce pipe expansion. The pipe expansion affect to pipe flexibility, so it is necessary to design an expansion loop. Expansion loop is a method used to increase flexibility in piping systems. This article aims to analyze symmetrical and non-symmetrical in vertical expansion loops whether it can increase flexibility and reduce pipe stress. This article conducts an expansion loop design with 3 trials, namely trial 1 (Vertical Expansion Loop), trial 2 (Nonsymmetrical Vertical Expansion Loop 1), and trial 3 (Nonsymmetrical Vertical Expansion Loop 2). The three trials were compared for flexibility and stress values based on ASME B31.3 requirements. The study results show that all trial 1, trial 2, and trial 3 have good flexibility with a value of 0.00016 because not exceed the requirements of ASME B31.3. The highest design code stress value in trial 1 is 5955 psi (Node A07F), trial 2 is 5906 psi (Node A05F), and trial 3 is 5906 psi (Node A06N). All trials have a code stress not exceeding the allowable stress (20000 psi). So that the symmetrical or nonsymmetrical design of the vertical expansion loop can both increase flexibility and reduce pipe stress.

Critical Analysis of the New High Cycle Fatigue Assessment Procedure From ASME B31.3—Appendix W

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.

The analysis of a piping system for improvement of a system in a process unit

The paper briefly covers the steps involved in designing and analysis of a piping system. An investigation was carried out to understand the different loads acting on the piping system and to incorporate the ways to reduce the stress acting on the system. The work involves new pressure vessels being installed in a unit of petrochemical industry situated in Mangaluru to fulfil the process requirement of the fluid which runs in the same unit. This article emphasizes the details which leads to the successful development of piping between the newly installed pressure vessel and the unit, in accordance with ASME B31.3. The reinforcement calculation was performed where the pipes are connected to the pressure vessels. An insight was briefed on various types of support coming up on the pipe line. The stress analysis is carried on the line using available software where it is subjected to various load cases like Sustained load case, Operational load case, and Expansion load case to make sure that the stresses in the pipe is within the allowable limit. Proof for the decrease of stress in the pipe line due to the incorporation of expansion loop and spring supports were provided

Application of Pipeline System Stress Analysis in Inspection

Industrial pipeline is generally laid overhead along the pipe gallery. When the pipeline changes from cold state to heat state, the pipeline will have thermal expansion, which will generate thermal displacement and thermal stress. As a kind of heat medium, Steam has been widely used in industrial production. The pipeline has been in service at high temperature for a long time, which is prone to metal material degradation such as graphitization and spheroidization. The accidents of steam pipeline occurred frequently in recent years, so we must pay more attention to the safety of steam pipeline. The traditional inspection method adopts a random sampling model which has the risk of over inspection and missing inspection. This paper introduced the stress analysis of a steam pipeline based on ASME B31.3. Through the software, the model of the pipeline was established. According to the calculation results, a targeted inspection scheme was established and the inspection was more economical and effective

ROUTING DESIGN ON THE PRIMARY COOLING PIPING SYSTEM IN PLATE-TYPE CONVERTED TRIGA 2000 REACTOR BANDUNG

In 2015, research activities to modify TRIGA 2000 Reactor Bandung fuel element from cylindrical to plate-type have been initiated. By using plate-type fuel elements, core cooling process will be altered due to different generated heat distribution. The direction of cooling flow is changed from bottom-to-top natural convection to top-to-bottom forced convection. This change of flow direction requires adjustment on the cooling piping system, in order to produce simple, economical, and safe piping route. This paper will discuss the design of suitable piping routing based on pipe stress and N-16 radioactivity. The design process was carried out in several stages which include thermal-hydraulic data of reactor core to determine the process variables, followed by modeling various pipeline routes. Based on available space and ease of manufacture, four possible alternative routings were determined. Four routings were produced and analyzed to minimize the amount of N-16 radioactivity on the surface of the reactor tank, prolonging the cooling fluid travel time to reach at least five times of N-16 half-life. Subsequent pipe stress analysis using CAESAR II software was conducted to ensure that the piping system will be able to withstand various loads such as working fluid load, pipe weight, along with working temperature and pressure. The results showed that the occurred stresses were still below the safety limit as required in ASME B31.1 Code, indicated that the designed and selected pipeline routing of primary cooling system in the Plate-type Converted TRIGA 2000 Reactor Bandung has met the safety standards.Keywords: TRIGA reactor, Cooling system modification, Pipeline routing design, Pipe stress analysis, N-16 radioactivity

ASME B31.1을 따른 크리프 영역 장기간 가동 고온 배관의 설계 비보수성 기술 현안

ASME B31.1을 따른 크리프 영역 장기간 가동 고온 배관의 설계 비보수성 기술 현안

Noise and Acoustic Fatigue Analysis in Valves (Case Study of Noise Analysis and Reduction for a 12″ × 10″ Pressure Safety Valve)

Safety and instrument engineers regularly analyze the noise in different types of valves to reduce its effect in sectors of the oil and gas industry such as offshore, refineries, and petrochemical plants. This paper reviews the mitigation strategies used to reduce acoustic fatigue and the risk of hearing damage from pressure safety valves and control valves used in piping systems. These two types of valves can generate high-frequency acoustical energy downstream of the valves. Different strategies are used to mitigate noise levels, such as installation of low-noise valves, process optimization to reduce the flow or delta pressure across valves, changing the valve design, acoustic piping installation, and increasing piping thickness. This paper discusses a case study of a noise calculation for a 12″ × 10″ pressure safety valve (PSV) at 1 m and 30 meters from the PSV discharge. The calculated noise level based on API 521, the standard for PSVs, has been compared with the maximum allowable noise limit from PSVs. The maximum allowable noise limit is calculated based on the NORSOK L-002 standard developed by Standards Norway. If the calculated noise level based on API 521 exceeds the allowable or acceptable noise limit based on NORSOK standards, the piping wall thickness should be increased to mitigate the risk of acoustic fatigue. The 12″ 6MO piping wall thickness outlet line of PSV is calculated based on the ASME B31.3 process piping code. The outlet pipe from PSV is in 6MO UNS 31254 material, which is expensive. Fortunately, there is no need to increase the piping wall thickness if the calculated noise based on the API 521 standard is within the accepted noise limit in the NORSOK standard.

Investigation of Corrosion Mechanisms in a Continuous Catalytic Regeneration (CCR) Platformer Unit

— Corrosion is prevalent throughout the world, none less so than in the oil and gas industry. Managing and mitigating corrosion in refining complexes is of paramount importance in order to prevent undesirable consequences such as major fires, explosions and Boiling Liquid Expanding Vapor Explosion (BLEVE) due to Loss of Primary Containment caused by the thinning and ultimate failure of pipelines and vessel walls. Analysis of a platformer unit at a Malaysian refinery has identified the occurrence of thermal fatigue and erosion corrosion on the Vent Gas Tower (VGT) Caustic Circulation line, which in turn has led to the excessive degradation of the walls of a venturi scrubber and the 8’’ caustic circulation line with initial thickness of 12.70mm. The rate of corrosion (0.88 mm/year) of the 8’’ caustic circulation line exceeds the standard allowable carbon steel corrosion rate (0.1 mm/year) as stated in API 571 Damage Mechanisms Affecting Fixed Equipment in the Refining Industry. This indicates that the circulation line has significant potential to fail which would lead to a major HSE incident. Based on these findings it is recommended that the refinery in question modifies the line by increasing the thickness of the line and include a cooling system to reduce temperature swing (ΔT) to below 93°C. Besides that, it is suggested that the implementation of Corrosion-Resistant Alloys (CRA) is conducted on the line. According to ASME B31.3 and supported by ASTM A 193, the line can be replaced with nickel-based alloy, alloy 800H and killed carbon steel which have high resistivity to corrosion than carbon steel. However, more comprehensive studies need to be conducted to identify the viable mitigation methods that are suitable to be implemented on the Vent Gas Tower (VGT) Caustic Circulation line.

A methodology for flexibility analysis of pipeline systems

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.

Operating Hydrogen Gas Transmission Pipelines at Pressures Above 21 MPa

Abstract The economical and efficient transportation of hydrogen gas is necessary for it to become a widespread source of energy. One way to improve the economics is to lower the cost of building hydrogen gas pipelines. The recent modification to the ASME B31.12 Code for Hydrogen Piping and Pipelines begins to lower the cost of building pipelines for hydrogen service by allowing the use of high-strength steel that will provide the same margin of safety with thinner pipe walls. Less steel directly impacts the cost of materials and welding. A means of improving efficiency would be to increase the hydrogen gas pressure to augment the volume of products transmitted through the pipeline. The recent B31.12 code modification characterized dozens of fatigue crack growth test results conducted in hydrogen gas pressurized up to 21 MPa with an upper boundary of fatigue crack growth rate (FCGR), defined as a function where all measured FCGRs fall below this boundary. In this study, different pipe geometries, strengths, and pressures with established design protocols were evaluated to determine if the code would require further modifications should linepipes be designed for higher hydrogen gas pressures, up to 34 MPa. It was shown through a numerical exercise that the code could be minimally modified and safety margins would be adequate for those pressures for steels up to and including API-5 L Grade X70.

Pipe stress analysis of first wall helium cooling system for conceptual design development of IN LLCB TBM

Indian TBM team is developing Lead-Lithium Cooled Ceramic Breeder (IN-LLCB) Test Blanket Module (TBM) along with its associated systems for testing in ITER. The outer box of LLCB TBM is cooled by first wall helium cooling system (FWHCS) which is designed to remove the heat load of ∼300 kW. FWHCS is a high temperature high pressure closed loop which produces significant movements and propagates high stresses in the piping system. This, in turn, leads to forces and moments on the supports and equipment nozzles. FWHCS may experience a high acceleration (∼59.69 m/s2) during seismic events, the deflection of pipes in this scenario may increase the complexity in the loop operation.This paper describes pipe stress analysis, methodology and results of FWHCS. The pipe stress analysis is performed for sustained and occasional load combinations for various ITER operating states as envisaged for TBMs. FWHCS piping is subjected to category I (likely event) and IV (extremely unlikely event, SL-2) loading conditions. The Pipe stress analysis is performed in accordance with ASME B31.3. The calculated stresses are within the limits for the considered cases. The highest value of stress (about 0.65 times the allowable stress) and the maximum displacement of 23 mm (x direction), 15 mm (y direction) and 11.5 mm (z direction) is observed in recuperator to electrical heater line. The obtained reaction and moment forces are needed as an input for the selection of pipe supports, location of supports and the verification of embedded plates loading criteria. This pipe stress analysis is also used in the optimization of FWHCS layout and further these inputs would be utilized in preliminary design phase.

Development of a Model for Hydrogen-Assisted Fatigue Crack Growth of Pipeline Steel1

Hydrogen has been proposed as a potential partial solution to the need for a clean-energy economy. In order to make this a reality, large-scale hydrogen transportation networks need to be engineered and installed. Steel pipelines are the most likely candidate for the required hydrogen transportation network. One historical barrier to the use of steel pipelines to transport hydrogen was a lack of experimental data and models pertaining to the fatigue response of steels in gaseous hydrogen. Extensive research at NIST has been performed in conjunction with the ASME B31.12 Hydrogen Piping and Pipeline committee to fill this need. After a large number of fatigue crack growth (FCG) tests were performed in gaseous hydrogen, a phenomenological model was created to correlate the applied loading conditions, geometry, and hydrogen pressure to the resultant hydrogen-assisted fatigue crack growth (HA-FCG) response of the steels. As a result of this extensive data set, and a simplification of the above-mentioned phenomenological model, the ASME B31.12 code was modified to enable the use of higher strength steels without penalty, thereby resulting in the potential for considerable installation cost savings. This paper details the modeling effort that led to the code change.

Application of Automatic TIG Welding for Yamal LNG Process Piping Fabrication

The representative materials, used in Russian Yamal LNG project, are ASTM A333 Gr.6 (low temperature carbon steel, designed temperature of –50°C) and ASTM A312/A358 TP304/304L (austenitic stainless steel, designed temperature of –196°C). The welding technical specification demands TIG (Tungsten Inert Gas) welding for root welding of piping. This project adopts the construction way of prefabrication in Qingdao and assembly in Russian. Therefore, high construction accuracy is required. This article introduces the LNG process piping welding by automatic TIG welding which contains welding process design, welding process parameters, test and analysis of weld mechanical property and advantage analysis of TIG welding as well. In this project, the automatic and high efficient TIG welding is used for the root welding and hot welding of low temperature carbon steel and austenitic stainless steel piping. The result shows that the mechanical properties of weld metals meet the requirements of LNG project technical specification and code ASME B31.3. The efficiency of automatic TIG welding increases 2 times compared with conventional manual TIG welding. The automatic TIG welding improves and optimizes the quality and construction progress of the LNG project process piping.

Mechanical Design and Analysis of LCLS II 2 K Cold Box

The mechanical design and analysis of the LCLS II 2 K cold box are presented. Its feature and functionality are discussed. ASME B31.3 was used to design its internal piping, and compliance of the piping code was ensured through flexibility analysis. The 2 K cold box was analyzed using ANSYS 17.2; the requirements of the applicable codes—ASME Section VIII Division 2 and ASCE 7-10—were satisfied. Seismic load was explicitly considered in both analyses.

A methodology for flexibility analysis of process piping

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.

Effect of Ovality in Inlet Pigtail Pipe Bends Under Combined Internal Pressure and In-Plane Bending for Ni-Fe-Cr B407 Material

Abstract The present paper makes an attempt to depict the effect of ovality in the inlet pigtail pipe bend of a reformer under combined internal pressure and in-plane bending. Finite element analysis (FEA) and experiments have been used. An incoloy Ni-Fe-Cr B407 alloy material was considered for study and assumed to be elastic-perfectly plastic in behavior. The design of pipe bend is based on ASME B31.3 standard and during manufacturing process, it is challenging to avoid thickening on the inner radius and thinning on the outer radius of pipe bend. This geometrical shape imperfection is known as ovality and its effect needs investigation which is considered for the study. The finite element analysis (ANSYS-workbench) results showed that ovality affects the load carrying capacity of the pipe bend and it was varying with bend factor (h). By data fitting of finite element results, an empirical formula for the limit load of inlet pigtail pipe bend with ovality has been proposed, which is validated by experiments.

Heating Coil Pipe Stress Analysis of Thermal Oil Plant on Fuel Oil Tanks of 17500 LTDW Product Oil Tanker

The heating coil pipe is one of the most important equipment in the thermal oil system. The pipe is located within each of the fuel tanks, which will be used as a place for thermal oil fluid flow in order to transfer heat to the fuel inside the tank. The equipment has been installed on 17500 LTDW Product Oil Tanker, MT. Parigi, but not yet tested. Meanwhile, the system will be operated at working pressure of 5 kgf/cm 2 and working temperature of 180 o C. Therefore, it is needed an evaluation or analysis to ascertain whether the equipment is capable of or not withstand the working pressure and working temperature of the system, namely pipe stress analysis. This analysis was performed by using the simulation of a software, namely Caesar II with ASME B31.3 as the code standard. The result concludes that the heating coil pipes inside each fuel tank are safe to operate, which means that the allowable stress of the pipe is bigger than the stress result value.

Statistical model and structural reliability analysis for onshore gas transmission pipelines

Abstract The reliability of gas pipelines against rupture can be estimated based on historical failure data and theory of structural reliability. In this study, an integrated model for reliability analysis of failure data is presented jointly with a robust structural reliability model for the purpose of comparison and cross-verification. The statistical model adopts a parametric hybrid empirical hazard model complemented with a robust data processing technique known as the nonlinear quantile regression for reliability analysis and prediction. This model provides inferences on the complete lifecycle reliability of the average pipe segment in the region under study. The structural reliability model is segment based and estimates rupture probabilities due to external metal loss corrosion. The non-homogeneous Poisson process is used to model the generation of new defects and the Poisson square wave process is used to model the growth of defects. The internal pressure load is modelled as a discrete Ferry-Borges stochastic process. Then, an inspection and maintenance plan is incorporated based on ASME B31.8S code of practice, for the service life considered. The probability of detection and measurement error of the inspection tools is also incorporated in the model. A numerical example of these models in an industrial context is presented. Onshore gas transmission pipeline rupture data for the period from 2002 to 2014, was obtained from the United States Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA) database and analysed. The comparative study of the proposed methodologies can assist gas pipeline operators in the informed implementation of optimal maintenance strategies based on risk prioritization.

Seismic Design of ITER Component Cooling Water System-1 Piping

The successful performance of ITER machine very much depends upon the effective removal of heat from the in-vessel components and other auxiliary systems during Tokamak operation. This objective will be accomplished by the design of an effective Cooling Water System (CWS). The optimized piping layout design is an important element in CWS design and is one of the major design challenges owing to the factors of large thermal expansion and seismic accelerations; considering safety, accessibility and maintainability aspects. An important sub-system of ITER CWS, Component Cooling Water System-1 (CCWS-1) has very large diameter of pipes up to DN1600 with many intersections to fulfill the process flow requirements of clients for heat removal. Pipe intersection is the weakest link in the layout due to high stress intensification factor. CCWS-1 piping up to secondary confinement isolation valves as well as in-between these isolation valves need to survive a Seismic Level-2 (SL-2) earthquake during the Tokamak operation period to ensure structural stability of the system in the Safe Shutdown Earthquake (SSE) event. This paper presents the design, qualification and optimization of layout of ITER CCWS-1 loop to withstand SSE event combined with sustained and thermal loads as per the load combinations defined by ITER and allowable limits as per ASME B31.3, This paper also highlights the Modal and Response Spectrum Analyses done to find out the natural frequency and system behavior during the seismic event.