Pressure Vessel End Caps
Dished End Bulkhead Assemblies
Dished end bulkhead assemblies are curved end caps, typically formed from Al-Li 2195 alloy, that seal the terminals of cylindrical pressure vessels. Commonly fabricated as 2:1 ellipsoidal or hemispherical geometries to distribute internal atmospheric loads, these components must maintain pressure integrity across a 100-year operational life against the external lunar vacuum. The head-to-cylinder junction creates a critical stress concentration zone validated through finite element analysis, making weld joints primary inspection targets. Furthermore, the bulkheads must incorporate penetrations for assembly manholes and docking ports while preserving the full pressure rating of the primary habitat structure.
Dished end caps sealing cylindrical pressure vessels at each end
Purpose
Dished end caps sealing cylindrical pressure vessels at each end
Context
Child of L2-STR-PRES
Principles
- ▸Hemispherical or ellipsoidal heads distribute pressure loads efficiently
- ▸Head-to-cylinder junction is highest stress region requiring careful design
- ▸Manhole openings in end caps enable internal access during assembly
- ▸Finite element analysis validates stress concentration at head-cylinder transition
Typical implementations
- ▸ASME BPVC Section VIII Division 2 head design rules
- ▸ISS module end cone designs
- ▸Orion crew module forward/aft bulkheads
Lunar considerations
- ▸End cap weld joints are critical inspection points for 100-year pressure integrity
- ▸Penetrations through end caps for docking ports must maintain full pressure rating
- ▸Ellipsoidal 2:1 heads offer good compromise between strength and internal volume
Specifications
Functional
| primary function | Dished end caps sealing cylindrical pressure vessels at each end |
Physical
| materials | Al-Li 2195 spun/formed heads, Weld prep machining, Dye penetrant inspection provisions |
Interfaces
Provides
- Pressure vessel end closure
Requires
- Docking port integration in end cap
Cite this entry
Lunar Ark Codex. "Pressure Vessel End Caps" (L3-STR-PRES-END). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-STR-PRES-END
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.