The edges of boiler pressure vessel plates are typically planed and beveled to an angle of______________?
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Answer: D. 80°
Explanation
Boiler plate edges are planed and beveled to approximately 80 degrees to prepare the joint for subsequent caulking and fullering operations. The beveled edge provides a convenient channel for driving metal tightly against the adjacent plate to ensure absolute pressure tightness. An 80-degree edge angle leaves a small vertical land at the bottom to support root welding and proper structural penetration. Boiler pressure vessels operate under extreme internal pressures, requiring exceptionally robust and leak-proof structural plate joints. Caulking involves hammering the edge of the plate into the adjoining plate to seal microscopic gaps against high-pressure steam leaks. Edge planing and beveling are standard mechanical preparation steps performed prior to assembly, riveting, or welding processes.
Option A (30 degrees) is typically used for heavy structural steel butt welding rather than traditional riveted boiler caulking edges. Option B (45 degrees) represents a standard standard welding bevel angle rather than the specialized 80-degree boiler caulking geometry. Options C and E are incorrect because standard boiler construction engineering codes specifically prescribe the 80-degree angle for edge preparation.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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