Who This Compressor Is For
- Fire brigades and emergency services — filling SCBA cylinders on scene or at base without mains electricity
- Dive centres and clubs — filling scuba tanks (200–300 bar) at locations without power: on a boat, beach or remote dive site
- Industrial safety — filling self-contained breathing apparatus (SCBA) at industrial facilities, mines and offshore platforms
- Rescue services — autonomous breathing air supply during emergency response
- Paintball and airsoft — filling HPA (High Pressure Air) cylinders up to 300 bar
The key advantage of the W31-5P-225-P2 over electric equivalents: complete autonomy — the 5.5 HP petrol engine delivers full operation without mains power, which is critical for field deployments, emergencies and remote site work.
What Is the W31 Mariner W31-5P-225-P2
The W31 Mariner is a high-pressure breathing air compressor made by ALKIN Compressors (Turkey, CE, ISO 9001, EN 12021 compliant). The W31 series is purpose-engineered for field conditions: petrol drive delivers full mains independence, and the compact frame structure allows straightforward handling and transport.
Model code breakdown — W31-5P-225-P2:
- W31 — series: W31 Mariner breathing air compressor;
- 5P — engine power: 5 HP, petrol (P = Petrol);
- 225 — standard cylinder filling pressure: 225 bar (maximum pressure: 350 bar);
- P2 — filtration system configuration: P2 (R21 system, 1 cartridge).
Fundamental difference from industrial compressors: the W31 Mariner is a breathing air compressor — the compressed air output meets EN 12021 (breathing air standard): CO ≤5 ppm, CO₂ ≤500 ppm, oil ≤0.5 mg/m³. This is fundamentally different from industrial compressors, whose output is not safe for breathing without further purification.
Technical Specifications
| Parameter | Value |
|---|---|
| Part number | W31-5P-225-P2 |
| Series / manufacturer | W31 Mariner / ALKIN Compressors (Turkey) |
| Drive type | Petrol engine |
| Engine power | 5.5 HP |
| Output capacity | 105 l/min |
| Working pressure | 330 bar |
| Maximum pressure | 350 bar |
| Minimum inlet pressure | 120 bar |
| Air quality standard | EN 12021 (breathing air) |
| Filtration system | R21 (1 cartridge) |
| Cartridge life | 300 m³ |
| Cartridge type | Refillable |
| Cartridge service interval | Every 50 operating hours |
| Dimensions (L×W×H) | 1030 × 430 × 520 mm |
| Weight | 68 kg |
| Warranty | 2 years |
| Availability | Available to order |
💡 Expert tip: when choosing between the W31-5P-225-P2 (5.5 HP) and the W32-13P-225-P4 (13 HP), base the decision on filling intensity. The W31 at 105 l/min suits 2–4 cylinder fills per hour (a dive club or small rescue team). The W32 at 280+ l/min suits 8–12 fills per hour (a fire station or large dive centre). For occasional field tasks the W31 is preferred for its lighter weight and fuel economy.
W31 and W32 Mariner Model Comparison
| Parameter | W31-5P-225-P2 (this model) | W32 Mariner |
|---|---|---|
| Drive | Petrol 5.5 HP | Petrol 13 HP |
| Output capacity | 105 l/min | 280+ l/min |
| Max. pressure | 350 bar | 350 bar |
| Filtration | R21 (1 cartridge) | P4 (4 cartridges) |
| Weight | 68 kg | ~120 kg |
| Application | Small teams, diving, field use | Fire stations, large dive centres |
| Warranty | 2 years | 2 years |
Cylinder Fill Time Estimates
| Cylinder type | Cylinder volume | Fill pressure | Approx. fill time |
|---|---|---|---|
| SCBA cylinder | 6.8 L | 300 bar | ≈ 20–25 min |
| SCBA cylinder | 9 L | 300 bar | ≈ 25–30 min |
| Scuba cylinder | 12 L | 200 bar | ≈ 25–35 min |
| Scuba cylinder | 15 L | 200 bar | ≈ 30–40 min |
| HPA paintball cylinder | 0.8 L | 300 bar | ≈ 2–3 min |
⚠️ Important: this compressor is designed for topping up cylinders (from 120 bar upward), not filling completely empty cylinders from scratch. Minimum inlet pressure: 120 bar. Filling from zero requires a cascade system.
Why Acvatron SRL — Official ALKIN Dealer in Moldova
Official ALKIN Compressors Dealership
Acvatron SRL is the official ALKIN Compressors (Turkey) dealer in Moldova. Compressors are supplied with the full manufacturer’s document package, CE certificates and EN 12021 compliance. You receive equipment with confirmed breathing air quality — not an unverified lookalike without documentation.
2-Year Warranty
Warranty service is provided through Acvatron SRL in Chișinău. Spare parts and consumables (R21 filtration cartridges) are available.
Engineering Consultation Before Ordering
A breathing air compressor is safety-critical equipment. Before the order is placed, the Acvatron SRL engineer advises on model selection (W31 vs W32), filtration system configuration and the right specification for your application.
Order-to-Delivery with Full Documentation
Manufacturer’s passport, CE Declaration of Conformity, EN 12021 certificate, warranty card. For legal entities — invoice and contract.
Service Support in Moldova
ALKIN compressor maintenance (cartridge replacement, servicing, repair) — in Chișinău. R21 filtration consumables available through Acvatron SRL.
Applications
Fire Brigades and Emergency Services
- Filling SCBA cylinders (MSA, Drager, Scott) on scene or at base
- Mobile filling station at incidents with no mains power
- Standby source when the fixed electric compressor is out of service
Diving and Underwater Work
- Filling scuba cylinders (200–300 bar) on boats, beaches and remote dive sites
- Mobile service dive centres
- Technical and cave diving (up to 350 bar)
Industrial Safety
- Filling self-contained breathing apparatus at chemical and petroleum facilities
- Mines and quarries — cylinder filling underground
- Offshore platforms — autonomous filling without shore infrastructure
Sport and Recreation
- Paintball and airsoft — filling HPA cylinders up to 300 bar
- Target shooting — filling PCP (Pre-Charged Pneumatic) airguns
Expert Opinion
“The W31 Mariner is the right choice for anyone who needs full autonomy: a petrol engine doesn’t tie you to a socket. At 68 kg it’s mobile at the level of ‘load it in a pick-up and go’. What’s important: the R21 filtration system is not just a filter — it’s the guarantee that the output air meets EN 12021 for breathing. The cartridge replacement every 50 hours is mandatory, not a recommendation. An overrun cartridge no longer delivers the required purification, and the air is visually indistinguishable from clean air. For organisations operating SCBA equipment, the cartridge is a matter of personnel safety, not cost-cutting.”
Vitali Bolucevschi, Chief Engineer at Acvatron SRL, 15 years in the industry
Applicable standards and certificates:
- EN 12021 — quality of compressed air for breathing apparatus
- CE — EU Machinery Directive 2006/42/EC
- ISO 9001 — ALKIN Compressors quality management system
- EN 14594 — requirements for breathing air compressors
How to Operate the W31 Compressor Correctly: 5-Step Procedure
- Check the R21 cartridge life before each use — life: 300 m³ or 50 hours; replacement is mandatory per the maintenance schedule, not based on air appearance.
- Position the compressor in a clean air zone — the air intake must be away from exhaust gases, smoke and chemical vapours; minimum distance from a pollution source: 3–5 m on the upwind side.
- Connect the cylinder and set the cut-off pressure — set the pressure regulator to the cylinder’s working pressure (200, 225, 300 or 330 bar); the compressor stops automatically when cut-off pressure is reached.
- Monitor engine temperature during extended operation — when filling multiple cylinders in sequence, allow 5–10 minute cooling breaks every 30–40 minutes of continuous running.
- Maintain an operating hours and cartridge replacement log — mandatory for organisations using the compressor to fill SCBA equipment, per industrial safety regulations.
FAQ
❓ How does the W31-5P-225-P2 differ from a standard high-pressure industrial compressor?
Three key differences. First — air quality: the W31 Mariner produces air meeting EN 12021 (breathing air standard), with CO ≤5 ppm and oil ≤0.5 mg/m³. An industrial HP compressor makes no such guarantee. Second — the R21 multi-stage purification cartridge (moisture, oil, CO, CO₂) is a built-in mandatory component. Third — CE and EN 12021 certification provides documentary proof of air fitness for breathing.
❓ How often must the R21 filtration cartridge be replaced?
Per ALKIN regulations: every 50 operating hours or when 300 m³ of compressed air has been delivered — whichever comes first. The cartridge is refillable — the sorbent fill can be replaced without buying a new housing. Replacement must be logged in the maintenance record for organisations operating SCBA equipment.
❓ Can the W31-5P-225-P2 fill a completely empty cylinder from scratch?
With limitations. The minimum inlet pressure (pressure already in the cylinder being filled) is 120 bar. Below this the compressor runs under excessive load, reducing valve group service life. For filling from zero, a cascade system is recommended: pre-charge the cylinder from an external source (another cylinder) to 120 bar, then top up with the compressor to working pressure.
