Fluid Feedthroughs
Hermetic Pipe Penetrations for Thermal and Water Lines
Fluid feedthroughs are hermetic pipe penetrations that route thermal control fluids and water lines across lunar habitat pressure boundaries. Built from 316L stainless steel nozzles with welded reinforcement pads, these assemblies preserve pressure vessel structural integrity while maintaining isolation against the external vacuum. Severe lunar thermal cycling drives continuous relative motion between internal piping and the vessel shell, requiring Inconel bellows expansion joints to absorb differential thermal displacement. For critical penetrations such as ammonia thermal cooling loops, double containment sleeves prevent catastrophic fluid loss into the living volume, while dedicated stainless steel isolation valves on both sides of the boundary permit maintenance without depressurizing the habitat.
Pipe penetrations passing thermal fluid and water lines through pressure boundaries
Purpose
Pipe penetrations passing thermal fluid and water lines through pressure boundaries
Context
Child of L2-STR-PEN
Principles
- ▸Welded penetration nozzles with reinforcement pads maintain pressure vessel strength
- ▸Bellows expansion joints accommodate thermal pipe movement relative to vessel wall
- ▸Double containment prevents fluid leak into pressure vessel if penetration seal fails
- ▸Isolation valves on both sides of penetration enable maintenance without depressurization
Typical implementations
- ▸ASME BPVC nozzle and reinforcement design rules
- ▸Nuclear containment pipe penetration assemblies
- ▸ISS fluid line penetration designs
Lunar considerations
- ▸Ammonia thermal loop lines are critical penetrations (leak = cooling loss)
- ▸Thermal cycling creates relative motion between pipe and vessel wall
- ▸Double containment adds mass but protects against catastrophic fluid loss
Specifications
Functional
| primary function | Pipe penetrations passing thermal fluid and water lines through pressure boundaries |
Physical
| materials | 316L stainless steel nozzles, Inconel bellows, Stainless steel isolation valves |
Interfaces
Provides
- Hermetic fluid routing through pressure walls
Requires
- Thermal fluid lines requiring pressure boundary crossing
Cite this entry
Lunar Ark Codex. "Fluid Feedthroughs" (L3-STR-PEN-FLUID). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-STR-PEN-FLUID
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.