Primary Water Storage Tank
Insulated Stainless Bladder-Lined Water Tank
The primary water storage tank is a 50-kilogram, 500-liter buffer vessel constructed with a 316L stainless steel shell and an internal metal bellows liner to deliver purified water to downstream settlement systems. To prevent freezing across severe lunar temperature swings and prolonged dark periods, multilayer insulation, foam, and a 50-watt polyimide heater maintain thermal stability. Because ambient vacuum conditions degrade conventional elastomers, the assembly utilizes metal seals and an elastomer-free barrier, enabling an operational lifetime of 25 years and a mean time between failures of 200,000 hours.
Primary insulated water storage tank (500 L) buffering purified water for downstream consumers, with thermal management to prevent freeze/excess heating.
Purpose
Primary insulated water storage tank (500 L) buffering purified water for downstream consumers, with thermal management to prevent freeze/excess heating.
Context
Child of L2-WTR-STOR in L1-WTR water processing chain
Principles
- ▸316L SS shell with EPDM-free bladder (metal bellows or PTFE liner)
- ▸MLI + foam insulation maintains temperature with minimal heater duty
- ▸Capacitive level gauge with redundant load-cell backup
- ▸Multiple isolation valves for fault containment
- ▸Vent to vacuum with vapor recapture
Typical implementations
- ▸ISS Potable Water Storage tanks heritage
- ▸Apollo/Shuttle reservoirs
- ▸Industrial pharmaceutical water-for-injection tanks
Lunar considerations
- ▸Freeze protection requires continuous low-power heating
- ▸Long-life metal seals avoid elastomer degradation
- ▸Modular replacement via L1-MNT
Specifications
Functional
| primary function | Primary insulated water storage tank (500 L) buffering purified water for downstream consumers, with thermal management to prevent freeze/excess heating. |
| capacity l | 500 |
| heater w | 50 |
Physical
| mass kg | 50 |
| materials | 316L SS shell, Metal bellows liner, Polyimide heater, MLI |
| vacuum compatibility | True |
Operational
| power consumption w | 50 |
| thermal range c | -40, 70 |
| lifetime years | 25 |
| mtbf hours | 200000 |
Interfaces
Provides
- Buffered water supply
Requires
- Purified water from polishing
- Heater (~50 W)
Cite this entry
Lunar Ark Codex. "Primary Water Storage Tank" (L3-WTR-STOR-TANK). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-WTR-STOR-TANK
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.