The Rainman Portable Watermaker (Petrol – 75L) is a self-contained, fuel-powered desalination system designed for maximum flexibility and independence. Operating without the need for electricity or a generator, it’s ideal for vessels looking to reduce battery load or for off-grid use during emergencies, remote cruising, or shore-based applications.
Two-piece system for easy setup and portability
This system consists of a petrol-powered Pressure Supply Unit (PSU) and a Reverse Osmosis (RO) unit. The PSU draws in seawater, filters out debris, and pressurizes the water for desalination. The RO unit then separates fresh water from the pressurized stream, producing up to 75 litres per hour depending on conditions. Approximately 20% of the input becomes clean, potable water, with the remainder discharged as brine.
- Honda-powered performance
Powered by the reliable Honda GXH50 2.1HP engine, the system uses a tensioned belt drive to operate both the lift pump and high-pressure pump. A 700ml fuel tank provides approximately 70 minutes of runtime, making it a dependable choice for extended use on the water.
| Enclosure | Two part system, pressure supply unit (PSU) and reverse osmosis unit (RO) | |
| Pressure Supply Unit (PSU) | Case of sturdy rotomoulded polyethylene | |
| RO Membranes | One 2.5" x 40" seawater membrane | |
| Reverse Osmosis Unit (RO) | Case of injection moulded polyethylene, strengthened with fibreglass reinforced nylon | |
| High Pressure Pump | General Pump WM triplex plunger pump | |
| Operating Pressure | 55 bar (800 psi) in seawater | |
| Pressure Relief Valve | Integrated General Pump 316SS/ceramic | |
| Prefilter | 5 micron | |
| Lift Pump | Integrated Rainman bronze flexible impeller | |
| Vertical Water Lift | 2 metres (6 ft) | |
| Power Source | Petrol (Gasoline) | |
| Power Use | 700ml fuel tank lasts 70 minutes | |
| Motor Type | Honda GXH50 (4 stroke) | |
| Subjective Sound Level | Slightly quieter than Honda 2.2kVA generator (max load) | |
| Measured Sound Level | 73dB | |
| HP Hose | 5 metre (16 ft) | |
| Product Water Hose | LDPE food grade product water hose | 3 metre (10 ft) 10 metre (33 ft) extension (8mm OD) |
| Brine Waste Hose | 3 metre (10 ft) brine waste discharge (10mm OD) | |
| Intake Hose | 3 metre (10 ft) fitted with one way valve to remain primed (1/2" ID), with detachable strainer | |
| Impeller | Included in pump (replacement Rainman MI813 or Jabsco Profile D 22405-0001-P) | |
| 5 Micron Prefilter | 1 in housing 4 spares 10" x 2.5" pleated poly | |
| Pickle Solution | 1 kg (2.2 lb) sodium metabisulfate powder | |
| Valve / Gauge Control | Integrated in RO unit | |
| Salinity Sensor | Optional hand held HM Digital COM-80 | |
| Product Water Flow Meter | Pop-up acrylic plastic analogue flow metre - 160lph/42gph | |
| RO Unit | 1,180 x 250 x 130mm (23.6 x 9.8 x 5.1”) | |
| Pressure Supply Unit (Modular) | 595 x 450 x 310mm (23.4 x 17.7 x 12.2") |