scholarly journals LOFT primary coolant addition and Control Piping System stress analysis

1978 ◽  
Author(s):  
S.M. Murdock
Keyword(s):  
Stress Analysis ◽  
Piping System ◽  
Primary Coolant ◽  
And Control

Control Valve Design Impact on Piping Vibration

2004 ◽  
Author(s):  
James McGhee ◽  
Doug Newlands ◽  
Stuart Farquhar ◽  
Herbert L. Miller
Keyword(s):  
Energy Levels ◽  
Control Valve ◽  
Piping System ◽  
Detection Systems ◽  
The North ◽  
Air Supply ◽  
The North Sea ◽  
Pipe Breakage ◽  
And Control ◽  
Fatigue Failures

Vibration of the recycle piping system on the Main Oil Line (MOL) Export Pumps from a platform in the North Sea raised concern about pipe breakage due to fatigue. Failures had already occurred in associated small bore piping and the instrument air supply lines and control accessories on the recycle flow control valves. Concern also existed due to the vibration of non-flowing pipe work and systems such as the deck structure, cable trays and other instrumentation, which included fire and gas detection systems. Many changes involving bracing of small bore attachments, stiffening of supports, adding supports and stiffing the deck structure were implemented without resolving the problem. The vibration was finally solved by adding enough pressure stages to assure the valve trim exit velcoities and energy levels were reduced to levels demonstrated historically as needed in severe service applications. This vibration energy reduction was more than 16 times. This was achieved by reducing the valve trim exit velocity from peaks of 74 m/s to 12 m/s (240 ft/s to 40 ft/s).

Influence of Local Wall Thinning and Support Stiffness in Piping Systems on Safety Assessments for Dynamic Loading

2014 ◽  
Author(s):  
Klaus Kerkhof ◽  
Fabian Dwenger ◽  
Gereon Hinz ◽  
Siegfried Schmauder
Keyword(s):  
Stress Analysis ◽  
Response Spectrum ◽  
System Response ◽  
Piping System ◽  
Load Bearing ◽  
Wall Thinning ◽  
Safety Margins ◽  
Piping Systems ◽  
Bearing Behavior ◽  
Local Wall Thinning

The load bearing behavior of piping systems depends considerably on support distances and stiffness as well as cross section characteristics. Stiffness of supports can often be defined only with difficulty by applying simplified procedures or guidelines based on assumptions. Load cases can be estimated quite well, but the safety assessment of a piping system can only be as reliable as the system model can realistically describe the present support stiffness or imperfections e.g. local wall thinning. As a consequence, the prediction of the system response may be poor. It is likely that calculated frequencies differ from natural frequencies determined experimentally. These frequency shifts lead to unrealistic predictions of stress analysis. Examples for overestimations and underestimations of stress analysis are given regarding the load case earthquake, depending on whether the frequency shift runs into or out of the plateau of the applied floor response spectrum. The influence of local wall thinning on modal characteristics is investigated. Conservative estimations of the influence on the load bearing behavior regarding severe local wall thinning are given. For fatigue checks the linear response of an experimental piping system is calculated and safety margins are demonstrated by comparing calculated with experimental results.

scholarly journals Thermal Stress Analysis of Process Piping System Installed on LNG Vessel Subject to Hull Design Loads

2020 ◽  
Vol 8 (11) ◽  
pp. 926
Author(s):  
Se-Yun Hwang ◽  
Min-Seok Kim ◽  
Jang-Hyun Lee
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Analysis ◽  
Evaluation Model ◽  
Element Model ◽  
Piping System ◽  
Wave Load ◽  
Element Analysis ◽  
Expansion Joints ◽  
Load Conditions

In this paper, the procedure for the strength evaluation of the piping system installed on liquefied natural gas (LNG) carriers is discussed. A procedure that accounts for the ship’s wave load and hull motion acceleration (as well as the deformation due to the thermal expansion and contraction experienced by the hull during seafaring operations) is presented. The load due to the temperature and self-weight of the piping installed on the deck is also considered. Various operating and load conditions of the LNG piping system are analyzed. Stress analysis is performed by combining various conditions of sustained, occasional, and expansion loads. Stress is assessed using finite element analysis based on beam elements that represent the behavior of the piping. The attributes of the piping system components (such as valves, expansion joints, and supports) are represented in the finite element model while CAESAR-II, a commercial software is used for finite element analysis. Component modeling, load assignment, and load combinations are presented to evaluate pipe stresses under various load conditions. An evaluation model is selected for the piping arrangement of LNG and the evaluated stress is compared with the allowable stress defined by the American Society of Mechanical Engineers (ASME).

Brittle Fracture Assessments on Offshore Piping Systems

2013 ◽  
Author(s):  
Kannan Subramanian ◽  
Jorge Penso ◽  
Graham McVinnie ◽  
Greg Garic
Keyword(s):  
Low Temperature ◽  
Brittle Fracture ◽  
Stress Analysis ◽  
Pressure Vessels ◽  
Piping System ◽  
Piping Systems ◽  
Assessment Approach ◽  
Section Viii ◽  
System Information ◽  
Safe Operating

Offshore piping systems may be subject to low temperatures due to operation related scenarios and are cause for brittle fracture concern. The analyses included in this work consider probable events leading to low temperature conditions such as auto-refrigeration. In such circumstances, brittle fracture assessments of piping are typically carried out using API 579-1/ASME FFS-1, latest referred as API 579, procedures. The assessment of piping systems are in many cases very involved, requiring extended piping system information followed by stress analysis and MAT calculations depending on the material type, thickness of the piping analyzed, and stress levels. In addition, the component-by-component assessment approach recommended in API 579 leads to tedious calculations. In this paper, approaches used for static and dynamic low temperature scenarios are presented. Static cases involve constant pressures and temperatures. Dynamic cases involve varying pressures and temperatures as the low temperature events unfold (e.g., blowdown of a valve or a vessel). Dynamic cases warrant the requirement of a safe operating envelope or MAT curve similar to those developed for pressure vessels. Case studies involving the influence of the extent of the system analyzed and the restraint conditions on the results are also presented. In addition, the importance of separately assessing the rated components such as flanges and valves away from the stress analysis is discussed. Based on the assessments carried out, a discussion on the toughness rules defined in ASME Section VIII Divisions 1, 2, and the original piping code of construction is provided.

scholarly journals KAJIAN TEKNOLOGI PEMANFAATAN BIOGAS POME (PALM OIL MILL EFFLUENT) KE BOILER

2019 ◽  
Vol 13 (1) ◽  
pp. 43-54
Author(s):  
Bambang Sucahyo ◽  
Dwi Lukman H ◽  
Rohmadi Ridlo ◽  
Tyas Puspita R ◽  
Erna Rosmala S
Keyword(s):  
Palm Oil ◽  
Valve Train ◽  
Control Panel ◽  
Piping System ◽  
Steam Boiler ◽  
Steam Boilers ◽  
Forced Draft ◽  
Gas Burner ◽  
Palm Oil Mill ◽  
And Control

In collaboration with BPPT,  PTPN V management starting in 2018 took place at the Sei Pagar  Mill PTPN V in Riau Province, planning the implementation of Biogas to Boiler technology to maximize the use of Biogas. The study aims to substitute shells for steam boilers / kettle through the scheme of using biomass POME to boilers at palm oil mills. The Utilization Model is a simple representation  of a complex process in reality. To produce the scheme the model was preceded by conducting technical studies and economic studies and comparative studies on several Mill s in Sumatra and Kalimantan. From some of the findings from the studies that were compiled, one of the most suitable models will be made that will be applied in the Sei Pagar Mill. Furthermore, from the model, still through the RISTEKDIKTI Flagship Insinas Program, it will be developed to produce Prototypes and Construction / modifications to the Existing Boiler that is applied to the Sei Pagar Mill . Utilization Model Scheme. Biogas POME to Boilers at Palm Oil Mill by applying Biogas to Boiler technology includes several components of equipment, such as: Blower, Piping System, Valve Train, Gas Burner (Single Burner), Forced Draft Fan, and Control Panel (PHB). Utilization Model. Biogas POME to Boilers at Palm Oil Mill can later be developed and implemented to support the application of Biogas to Boiler technology at Palm Oil Mills in Indonesia.Keywords: Steam Boiler / Boiler, Blower, Piping System, Valve Train, Gas Burner (Single Burner), Forced Draft Fan, and Control Panel (PHB)

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

2019 ◽  
Vol 21 (3) ◽  
pp. 107
Author(s):  
Veronica Indriati Sri Wardhani ◽  
Henky Poedjo Rahardjo ◽  
Rasito Tursinah
Keyword(s):  
Stress Analysis ◽  
Cooling System ◽  
Flow Direction ◽  
Reactor Core ◽  
Working Fluid ◽  
Piping System ◽  
Research Activities ◽  
Routing Design ◽  
Core Cooling ◽  
Plate Type

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

Sign in / Sign up

Export Citation Format

Share Document