Alkin Compressors W31 Mariner
Specifications
- Max pressure
- 5,000 psi (345 bar)
- Cooling
- air, stainless steel intercoolers and aftercoolers
- Moisture handling
- P21 purifier with refillable purifier element; 2nd and 3rd stage water/condensate and oil separator; EN12021 certified breathing air
- Auto-stop
- Yes
- Duty cycle
- continuous duty rated per community comparison against Bauer
- Weight
- 165 lb
- Vessel guidance
- High-volume tank filling; ships ready to run with oil and filter cartridges pre-installed
- Also sold as
- Alkin W31
Estimated fill times
| Vessel | 0 → 250 bar | 200 → 300 bar |
|---|---|---|
| gun cylinder 0.3L | 0.6 min | 0.3 min |
| 1L bottle | 2.1 min | 0.8 min |
| 2L bottle | 4.2 min | 1.7 min |
| 3L bottle | 6.3 min | 2.5 min |
| 6.8L (74ci) tank | 14.3 min | 5.7 min |
| 9L (97ci) tank | 18.9 min | 7.6 min |
All values estimated from stated manufacturer or reviewer benchmarks (1 benchmark); treat as run-time, not wall-time, past the unit's duty-cycle guidance.
Where to buy
Prices captured 2026-07-06; follow the link for current pricing and stock.
About Alkin Compressors
Alkin's W31 and W32 are dive-grade compressors with a strong following among high-volume airgunners who fill many tanks and want a machine measured in decades rather than years. The W31 Mariner runs a three-stage reciprocating pump at a deliberately low 1050 RPM for cooler, quieter, longer-lived operation, with stainless steel intercoolers and aftercoolers and EN12021-certified clean air output. It ships ready to run with oil and filter cartridges installed.
Own one?
Add it to your free Virtual Locker: link it to your guns, log maintenance, and keep photos and fill notes in one place.
Open my locker →Specifications come from manufacturer pages and named retailer listings; blanks mean a value wasn't published, not that it's zero. Fill-time figures are derived estimates, not lab measurements. Always follow the manufacturer's fill and duty-cycle guidance.