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At least 91 records · Page 5

Low conducting metal screen support flange

In a very high or very low temperature duct system in which duct insulation is terminated at selected locations so as to be not coextensive with the duct, an annular metal perforated or mesh screen support flange is used, as a low conductor of heat or cold, between the duct and an outer insulation cover to retain the end of the insulation and to support its usually very thin cover. The screen may be Z-shaped in cross section having a small diameter annular portion to surround and be secured to the duct adjacent the end of the insulation. A generally radially extending portion of the screen extends outwardly from the small diameter portion and adjacent the end of the insulation. The periphery of the radially extending portion is in alignment with the outer peripheral surface of the insulation and the outer peripheral surface of the insulation cover. A large diameter annular portion of the screen extends longitudinally from the periphery in the direction opposite the small diameter portion, and is adapted to surround the insulation and its cover and be secured thereto. The screen may also be U or channel-shaped with one longitudinally directed leg secured to the insulation cover and the other leg secured to the duct under the insulation.

Lestak, Robert G.↗

Elastic-Plastic Fracture Mechanics Analysis of Critical Flaw Size in ARES I-X Flange-to-Skin Welds

NASA's Ares 1 Upper Stage Simulator (USS) is being fabricated from welded A516 steel. In order to insure the structural integrity of these welds it is of interest to calculate the critical initial flaw size (CIFS) to establish rational inspection requirements. The CIFS is in turn dependent on the critical final flaw size (CFS), as well as fatigue flaw growth resulting from transportation, handling and service-induced loading. These calculations were made using linear elastic fracture mechanics (LEFM), which are thought to be conservative because they are based on a lower bound, so called elastic, fracture toughness determined from tests that displayed significant plasticity. Nevertheless, there was still concern that the yield magnitude stresses generated in the flange-to-skin weld by the combination of axial stresses due to axial forces, fit-up stresses, and weld residual stresses, could give rise to significant flaw-tip plasticity, which might render the LEFM results to be non-conservative. The objective of the present study was to employ Elastic Plastic Fracture Mechanics (EPFM) to determine CFS values, and then compare these values to CFS values evaluated using LEFM. CFS values were calculated for twelve cases involving surface and embedded flaws, EPFM analyses with and without plastic shakedown of the stresses, LEFM analyses, and various welding residual stress distributions. For the cases examined, the computed CFS values based on elastic analyses were the smallest in all instances where the failures were predicted to be controlled by the fracture toughness. However, in certain cases, the CFS values predicted by the elastic-plastic analyses were smaller than those predicted by the elastic analyses; in these cases the failure criteria were determined by a breakdown in stress intensity factor validity limits for deep flaws (a greater than 0.90t), rather than by the fracture toughness. Plastic relaxation of stresses accompanying shakedown always increases the calculated CFS values compared to the CFS values determined without shakedown. Thus, it is conservative to ignore shakedown effects.

Chell, G. Graham↗

Flanged Tritium Waste Containers (FTWCs) Project Update [Slides]

Stakeholder engagement, outreach, and collaboration has been extensive throughout all project phases. Numerous alternatives were considered, and included SME and regulator input and consultation. All aspects of this operation have been specifically designed to prioritize the protection of our workers, the public, and the environment. This project is a one-time effort to prepare four unique waste containers for permanent offsite disposal.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Flange Tritium Waste Containers Operational Concerns: How to Address the Issues Through the Venting Design

As a part of the U.S. Department of Energy (DOE), Los Alamos National Laboratory (LANL or Laboratory) must comply with regulations in the Clean Air Act (CAA) put forth in 40 Code of Federal Regulations (CFR) 61, Subpart H “National Emission Standards for Emissions of Radionuclides Other Than Radon from Department of Energy Facilities.” The standard states, “Emissions of radionuclides to the ambient air from Department of Energy facilities shall not exceed those amounts that would cause any member of the public to receive in any year an effective dose equivalent of 10 mrem/yr [millirem per year] [1].” This regulation is referred to as the National Emission Standards for Hazardous Air Pollutants for Radionuclides (Radionuclide NESHAP or Rad-NESHAP).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Flange weld pressure testing

Device allows localized high-pressure proof test. Use of tool eliminates need to block off far end of pipe; only small amount of pressurizing gas is needed; only small area needs to be cleared of personnel for proof test.

Holden, C. F.↗

Elastic distortion of flanged inner ring of high-speed cylindrical roller bearing

The elastic distortion of the inner ring of an experimental roller bearing is investigated analytically. The geometry of the experimental bearing is unusually complex, and for this reason a bearing with an axially symmetric inner ring is also analyzed. Only the inner ring and shaft are considered using a two dimensional finite element program that can accommodate interference between these components. The results suggest that the elastic distortions are modest in relation to the design clearances associated with the experimental bearing. The variation of the radial deflection of the raceway may, however, be significant in some circumstances.

Taylor, C. M.↗

The elastic distortion of the flanged inner ring of a high-speed cylindrical roller bearing

The elastic distortion of the inner ring of an experimental 3,000,000 DN roller bearing is investigated analytically. The geometry of this bearing is unusually complex and for this reason a bearing with an axially symmetric inner ring and shaft is also analyzed. Only the inner ring and shaft are considered using a two-dimensional finite element computer program which enables interference between these components to be accommodated. The results for the experimental bearing suggest that elastic distortions are modest in relation to the design clearances. However, the variation of the radial deflection of the raceway may be significant for some circumstances and the interference fit adopted between the ring and shaft appears to be questionably low.

Taylor, C. M.↗

Approximate Stress Analysis of Multistringer Beams with Shear Deformation of the Flanges

The problem of the skin-stringer combinations used as axially loaded panels or as covers for box beams is considered from the point of view of the practical stress analyst. By a simple substitution the problem is reduced to the problem of the single-stringer structure, which has been treated in NACA Report no. 608. The method of making this substitution is essentially empirical; in order to justify it, comparisons are shown between calculations and strain-gage tests of three beams tested by the author and of one compression panel and three beams tested and reported elsewhere.

Kuhn, Paul↗

8-inch Reflange Inlet and Two 6-inch 600# Flange Outlets Relief Valve Description and Specifications

In the past, an Anderson Greenwood (AG) pilot operated relief valve was used to protect the E-1 rocket engine test facility. It was found that the AG valve is destroyed and discharges internal parts at a great velocity on opening. This is a major safety and cost issue. The solution is a relief valve to match present Anderson Greenwood pilot valve A 8z B dimensions. The valve is to use a precise buckling pin obeying Euler s Law to act as the pressure sensor and actuator. The valve must not self destruct on opening.

Source record↗