Distribution Pump
Magnetic-Coupled Centrifugal Water Pump
The distribution pump is a 4-kilogram magnetic-coupled centrifugal pump that delivers purified water across the Ark at 5 liters per minute under 3 bar of head. In the lunar vacuum, dynamic shaft seals present severe leakage risks, necessitating a seal-less drive with samarium-cobalt magnets and bellows-sealed bearings to maintain fluid containment. Powered by a 100-watt variable-speed brushless DC motor, the unit drives a 316L stainless steel impeller to overcome piping pressure drops between 1 and 5 bar. Installed in a 1+1 redundant configuration to enable hot-swap maintenance, the assembly provides a 20-year operating life and a 120,000-hour mean time between failures.
Magnetic-coupled centrifugal pump distributing purified water across the Ark without shaft-seal leakage risk.
Purpose
Magnetic-coupled centrifugal pump distributing purified water across the Ark without shaft-seal leakage risk.
Context
Child of L2-WTR-DIST in L1-WTR water processing chain
Principles
- ▸Magnetic coupling eliminates shaft-seal failure mode
- ▸Centrifugal head matches piping pressure drop (1-5 bar typical)
- ▸Variable-speed BLDC motor matches flow to demand
- ▸Bellows-sealed bearings for vacuum operation
- ▸Redundant pump pair (1+1) for continuous availability
Typical implementations
- ▸ISS WPA water distribution pumps (heritage)
- ▸Industrial magnetic-drive pumps (Iwaki, March)
- ▸Apollo/Shuttle potable-water distribution
Lunar considerations
- ▸No shaft seal eliminates a major lunar-mission failure mode
- ▸Long-life motor with sealed gearbox
- ▸Redundant pump enables hot-swap maintenance
Specifications
Functional
| primary function | Magnetic-coupled centrifugal pump distributing purified water across the Ark without shaft-seal leakage risk. |
| flow rate lpm | 5 |
| head bar | 3 |
| redundancy | 1+1 |
Physical
| mass kg | 4 |
| materials | 316L SS impeller, SmCo magnet drive, BLDC motor |
| vacuum compatibility | True |
Operational
| power consumption w | 100 |
| thermal range c | -40, 70 |
| lifetime years | 20 |
| mtbf hours | 120000 |
Interfaces
Provides
- Pressurized water flow
Requires
- Purified water input
- Motor power (~100 W)
Cite this entry
Lunar Ark Codex. "Distribution Pump" (L3-WTR-DIST-PUMP). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-WTR-DIST-PUMP
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.