Application of the ASME Code SEC III Pressure Design Requirements on Locally Thinned Tight Radius Pipe Bends

2010 ◽  
Author(s):  
Usama Abdelsalam
Keyword(s):  
Wall Thickness ◽  
Thickness Distribution ◽  
Element Model ◽  
Thickness Variation ◽  
Pipe Bend ◽  
Linear Elastic ◽  
Primary Stress ◽  
Asme Code ◽  
Wall Thickness Variation ◽  
Code Compliance

This paper addresses the primary stress requirements for the pressure loading of tight radius pipe bends according to the ASME Code SEC III NB-3200 (Design by Analysis). Solid FEA models are constructed to represent a tight radius pipe bend with general and local internal wall thinning. The wall thickness variation is considered using uniform and non-uniform axial and circumferential profiles. It is demonstrated that for a tight radius bend with wall thickness equal to the pressure based thickness of the corresponding straight pipe, the linear elastic criteria of NB-3221 are significantly exceeded. Results are presented to show the minimum acceptable wall thickness using uniform thickness distributions. The allowable wall thickness criterion of the ASME Code SEC XI Code Case N-597-2 is examined using a finite element model implementing the recommended thickness distribution along the circumferential direction. It is demonstrated that this distribution achieves a uniform stress intensity over the entire bend (uniform strength). A local thin area (LTA) centered at the intrados of the bend is super-imposed on a general thinned area and the axial and circumferential extents are varied. FEA results are presented to demonstrate Code compliance and its dependency on the axial and circumferential extents of the LTA and the thickness of the surrounding material.

ASME Code Qualification of Pipe Bends With Localized Wall Thinning

2010 ◽  
Author(s):  
Usama Abdelsalam ◽  
Dk Vijay
Keyword(s):  
Wall Thickness ◽  
Thickness Distribution ◽  
Axial Direction ◽  
Rate Function ◽  
Elastic Analysis ◽  
Dead Weight ◽  
Pipe Bend ◽  
Fea Model ◽  
Class 1 ◽  
Asme Code

This paper addresses the application of the design by analysis rules of the ASME B&PV Code SEC III Division 1 NB-3200 criteria on degraded Class 1 piping. A tight radius pipe bend with a local thin area (LTA) located on the inner surface and super imposed on general thinning region is considered using a detailed FEA model implementing idealized smooth axial and circumferential thickness profiles. A location dependent thinning rate function is developed (based on the smoothed profiles and the assumed original thickness distribution) to predict the wall thickness distribution at the end of an arbitrary evaluation period. Internal pressure and dead weight loads are statically applied. Linear elastic analysis is performed and the results are checked against the ASME Code criteria for the primary stress intensity. It is demonstrated that a “local” wall thickness considerably below the pressure based thickness for the corresponding straight pipe segment meets the requirements of the ASME Code SEC III for the primary stresses. The effect of the extent of the local thin area in the axial direction is explored. This paper also compares the allowable pressure obtained from elastic analysis of NB-3221 and limit analysis of NB-3228.1.

Analysis of Dimensional Accuracy of Spun Parts by Taguchi Approach

2012 ◽  
Vol 217-219 ◽  
pp. 2423-2426 ◽  
Author(s):  
Peter Šugár ◽  
Jana Šugárová ◽  
Ladislav Morovič ◽  
Peter Zemko
Keyword(s):  
Wall Thickness ◽  
Thickness Distribution ◽  
Dimensional Accuracy ◽  
Thickness Reduction ◽  
Thickness Variation ◽  
Distribution Analysis ◽  
Experimental Sample ◽  
Scanning Method ◽  
Wall Thickness Variation ◽  
Formed Part

The paper brings the results of wall thickness distribution analysis of formed part produced by CNC multi-pass conventional metal spinning. The thickness reduction was measured by optical 3D scanning method and the influence of the feed, workpiece geometry and planar anisotropy of the blank on the wall thickness reduction was studied. For experiment design, an orthogonal array L27 was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the highest reduction of wall thickness is observed in the conical part of the experimental sample. Workpiece geometry is the most important factor which influences the wall thickness variation.

Mechanics of Conventional Spinning

1963 ◽  
Vol 85 (4) ◽  
pp. 346-350 ◽  
Author(s):  
H. C. Sortais ◽  
S. Kobayashi ◽  
E. G. Thomsen
Keyword(s):  
Wall Thickness ◽  
Pure Aluminum ◽  
Tangential Force ◽  
Deformation Energy ◽  
Thickness Variation ◽  
Force Component ◽  
Commercially Pure ◽  
Conventional Spinning ◽  
Wall Thickness Variation ◽  
Experimental Values

In conventional spinning of cones, the cone-wall thickness variation was studied using blanks of 1100-0 commercially pure aluminum sheet of 0.050-in. thickness. The results revealed that the radial stress induced in the unspun flange is the major cause of nonuniform wall thickness of spun cones. The theoretical tangential force component was derived by use of the deformation energy method. Qualitative agreement was found between the theoretical and the experimental values of tangential force component in the underspinning conditions.

Injection-Moulded Models of Major and Minor Arteries: The Variability of Model Wall Thickness Owing to Casting Technique

2005 ◽  
Vol 219 (5) ◽  
pp. 381-386 ◽  
Author(s):  
T O'Brien ◽  
L Morris ◽  
M O'Donnell ◽  
M Walsh ◽  
T McGloughlin
Keyword(s):  
Wall Thickness ◽  
Ccd Camera ◽  
Western Society ◽  
Experimental Investigations ◽  
Thickness Variation ◽  
Casting Technique ◽  
Radiological Images ◽  
Thickness Variability ◽  
Wall Thickness Variation ◽  
Integrated Technique

Cardiovascular disease of major and minor arteries is a common cause of death in Western society. The wall mechanics and haemodynamics within the arteries are considered to be important factors in the disease formation process. This paper is concerned with the development of an efficient computer-integrated technique to manufacture idealized and realistic models of diseased major and minor arteries from radiological images and to address the issue of model wall thickness variability. Variations in wall thickness from the original computer models to the final castings are quantified using a CCD camera. The results found that wall thickness variation from the major and minor idealized artery models to design specification were insignificant, up to a maximum of 16 per cent. In realistic models, however, differences were up to 23 per cent in the major arterial models and 58 per cent in the minor arterial models, but the wall thickness variability remained within the limits of previously reported wall thickness results. It is concluded that the described injection moulding procedure yields idealized and realistic castings suitable for use in experimental investigations, with idealized models giving better agreement with design. Wall thickness is variable and should be assessed after the models are manufactured.

Study on Three-Way Pipe’s Internal High Pressure Forming Simulation

2013 ◽  
Vol 589-590 ◽  
pp. 517-522
Author(s):  
Shi Gang Wang ◽  
Fu Sheng Gao ◽  
Feng Lan Cheng ◽  
Qiang Guo
Keyword(s):  
High Pressure ◽  
Wall Thickness ◽  
Three Dimensional ◽  
Thickness Variation ◽  
Forming Simulation ◽  
Finite Element Software ◽  
Plastic Processing ◽  
Wall Thickness Variation ◽  
Dimensional Shape ◽  
Pressure Parameter

Internal high pressure forming is a kind of the modern plastic processing technology. Using liquid as the pressure transmitting medium, explore the effect of internal high pressure parameter on the three passing pipe technique, internal high pressure forming technique is applied on the three-dimensional shape parts deformation. In this study, we simulate the three-way pipe process by finite element software, analyze the forming force influence to the tube forming quality and get the changeable regulation of the pipe wall thickness with conclusion of the wall thickness variation, which provides the reference data and guidance for the actual production of the three-way pipe.

scholarly journals A Design Approach of Porthole Die for Flow Balance in Extrusion of Complex Solid Aluminum Heatsink Profile with Large Variable Wall Thickness

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 553
Author(s):  
Tat-Tai Truong ◽  
Quang-Cherng Hsu ◽  
Van-Canh Tong ◽  
Jinn-Jong Sheu
Keyword(s):  
Wall Thickness ◽  
Metal Flow ◽  
Die Design ◽  
Design Approach ◽  
Thickness Variation ◽  
Extrusion Force ◽  
Bridge Structure ◽  
Flow Balance ◽  
Porthole Die ◽  
Wall Thickness Variation

In this study, porthole die used for extrusion of a solid heatsink profile with wall thickness variation ratio up to 15.3 was designed using finite element (FE) simulations. To improve the flow balance in the die, a design approach was introduced to find the appropriate die structure, which includes the porthole and pocket geometry correction, the bearing length adjustment, and the port bridge structure modification. Using the proposed die, the predicted velocity relative difference (VRD) and the maximum velocity difference (ΔV) of extrudate were significantly lower than those of an initial die, which was preliminarily designed based on general design experiences. The required extrusion force and the residual stress in the product were also reduced significantly. Then, the effects of the port bridge structure and welding chamber height on the behavior of the metal flow in the die were investigated. To verify the proposed die design, experimental extrusions were conducted on a 930-ton extruder. The experiment results showed that the extruded product fulfilled the requirements for dimensional tolerances. The design approach presented in this paper can be useful for practical implementation of die design when extruding similar solid heatsink profiles with large wall thickness variation.

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