Vessel supports: for which type of equipment is a skirt support the most appropriate and commonly used solution from structural and thermal viewpoints?
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Asmall horizontal
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Blarge horizontal
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Ctall vertical
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Dthick walled
Answer
Correct Answer: tall vertical
Explanation
Introduction / Context:Process vessels require supports that safely transmit loads (weight, wind, seismic, thermal) to foundations. Support selection depends on geometry, size, and operating conditions. Skirt supports are a standard choice in many plants.
Given Data / Assumptions:
- Cylindrical pressure or storage vessels.
- Outdoor installation subject to wind and thermal expansion.
- Need for access and nozzle clearance near the bottom head.
Concept / Approach:A skirt support is a cylindrical shell welded to the vessel bottom head, transferring loads axially to a base ring and anchor bolts. It provides excellent resistance to overturning moments from wind/seismic on tall vertical equipment while keeping the shell free of local leg loads. It also accommodates thermal expansion via a defined hot-to-cold interface and allows insulation clearance.
Step-by-Step Solution:Identify vessel category needing overturning resistance: tall vertical columns, reactors, and towers.Select support that gives strong moment capacity and clean load path: skirt support.Conclude that “tall vertical” vessels are the best match.
Verification / Alternative check:Design standards and vendor catalogues pair skirts with columns/towers, saddles with horizontal vessels, and legs/lugs for small vertical drums.
Why Other Options Are Wrong:Small/large horizontal: Better served by saddles.Thick walled: Wall thickness alone does not dictate the support type; geometry and moment loads do.
Common Pitfalls:Locating heavy nozzles on skirts without considering differential expansion; underestimating anchor bolt design for overturning.
Final Answer:tall vertical