Filter and sort
What are 12V pressure pumps and what are they used for?
12V pressure pumps are compact devices, usually diaphragm type, designed to maintain constant pressure in the internal water network using direct 12 V DC power from batteries. They are the preferred solution in boats, motorhomes, and off-grid homes due to their low consumption, self-priming capability, and ease of integration with solar systems. This collection is part of Pressure Pumps and is complemented by accessories (filters, expansion tanks, valves) and spare parts for maintenance.
Advantages and limitations
- Off-grid efficiency: low consumption and automatic start/stop via pressure switch.
- Simple installation: compact design, self-priming, and quick maintenance.
- Versatility: suitable for service water in taps, showers, and small pressurized outlets.
- Limitations: current at 12 V is high; it is advisable to minimize cable length and avoid insufficient cross-section. For longer distances or higher demands, consider 24V or 230 V.
Applications
- Marine: fresh water pressure in kitchen and bathroom, with low noise and smooth starts.
- Camper/motorhome: supply to 1–3 points with intermediate tank.
- Small off-grid home: support for sink/shower with appropriate tank and water heater.
- Light irrigation and pressurized transfers over short distances.
How to choose
- Flow rate (l/min): 6–10 l/min for 1–2 points; 12–19 l/min for 2–3 simultaneous points.
- Pressure (PSI/bar): 30–60 PSI covers most uses; up to 100 PSI in specific models.
- Usage profile: intermittent (typical in taps/showers) vs. continuous. Add an expansion tank to reduce cycles, water hammer, and noise.
- Electrical installation: adequate cable cross-section, fuse/MCB, and good grounding; at 12 V, prioritize short runs to limit voltage drop.
- Water quality: install an inlet filter (≈50 µm) to protect the diaphragm and internal valves.
Indicative technical specifications
| Operating voltage | 12 V DC |
| Typical flow rate | 2–18.9 l/min depending on model |
| Service pressure | 30–100 PSI (≈2–6.9 bar) |
| Self-priming | Yes (depending on suction height) |
| Control | Integrated pressure switch/press-control |
| Key accessories | Expansion tank 20–50 L, 50 µm filter, non-return valve |
Best installation practices
- Place the pump near the tank and below the water level if possible; avoid unnecessary elbows and narrow sections.
- Install a filter on the suction side and purge air at first start-up.
- Use flexible hoses with damping to reduce vibrations and noise.
- Adjust the cut-off pressure (if adjustable) according to your internal network and water heater.
- Maintenance plan: check connections, diaphragm condition, and replace filters periodically; keep critical spare parts (pressure switch, valves, diaphragm).
Comparisons and related accessories
If you need longer cable runs or lower current, consider 24V Pressure Pumps. With 230 V grid/inverter, check AC Pressure Pumps. For operation with panels and batteries, this family integrates into Solar Pressure Pumps. Complete the installation with accessories (expansion tank, filter, electrical protections) and return to the overview at Pressure Pumps.
