A dished head comprises a straight flange, corner torus, and central dished section. How are the crown radius and knuckle radius related__________________?
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Answer: A. Central dished section and corner torus section
Explanation
Dished heads integrate straight flanges, corner torus regions, and central dished sections into one geometry. Standard design codes define precise geometric relationships between central crown radii and corner knuckle radii. This geometric proportionality ensures smooth stress distribution across the curved pressure vessel head surface. Pressure vessel heads close cylindrical shell ends to contain internal fluids safely under high pressures. Torispherical dished heads combine a spherical crown radius with a toroidal knuckle radius for economical fabrication. ASME boiler and pressure vessel codes specify exact ratios for crown and knuckle radii to prevent buckling.
Pressure vessels and storage tanks utilize torispherical heads as end closures to minimize high stress concentrations. Fabrication of dished heads requires specialized metal spinning or pressing equipment to achieve correct curvature. Engineers calculate head thickness requirements based on internal pressure and crown-to-knuckle radius proportions. Option B reverses the primary structural relationship incorrectly by confusing crown and knuckle radius dependencies. Option C references straight flange sections which do not participate in crown and knuckle radius sizing formulas. Option D incorrectly pairs straight flanges with corner torus sections instead of relating crown and knuckle radii.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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