SEAFLO 51 Series 12V 5.0GPM 60PSI Water Pressure Pump Marine RV

12V high-flow automatic demand water pump

The SEAFLO SFDP1-050-060-51 NEW is a heavy-duty five-chamber diaphragm pump for automatic pressurised water supply. The integrated pressure switch starts the pump when a tap opens and stops it at 60 PSI when outlets close. With up to 18.9 LPM open flow, it is intended for higher-demand systems serving up to four fixtures.

Suitable boats, vehicles and water systems

• 12V motorboats, sailing yachts, cabin cruisers, houseboats and fishing boats supplying galley, basin, shower or toilet water from a tank.
• 12V motorhomes, caravans and remote cabins with a suitably designed holding-tank water system.
• Suitable as a replacement only where the existing circuit can safely supply up to 17 A and the plumbing is rated for 60 PSI.
• The manufacturer offers fresh- or salt-water configurations; confirm the exact fluid compatibility of the full installation.
• Not designed as a bilge, fuel, sewage or macerator pump.

Verified technical specification

Compatibility and installation checks

• Confirm a 12V DC supply capable of the 17 A maximum draw. This is not a direct replacement for a low-current pump without checking cable and fuse capacity.
• Use appropriately rated marine cable, fuse and isolation switch for the full cable length to prevent voltage drop and overheating.
• Confirm 1/2-14 MNPT connections and ensure every hose, tap, calorifier/water heater and fitting is rated above 60 PSI.
• Install an inlet strainer and flexible hose sections; mount in a dry, ventilated and accessible location.
• Run-dry capability is for normal workloads, not deliberate extended operation with an empty tank or blocked inlet.
• Package: one SEAFLO 51 Series pump. Strainer, hose, adaptors, fuse and wiring components are separate unless pictured.

Frequently asked questions

Why is the 17 A rating important?

The pump circuit, fuse, switch and cable must safely carry the maximum load. An undersized circuit can cause voltage drop, poor performance and overheating.

Does it include an automatic pressure switch?

Yes. The built-in demand switch controls starting and stopping as outlets open and close.

Does it require an accumulator?

Not normally. SEAFLO states that the 51 Series can operate without one in a correctly designed system.

Can it replace a smaller 12V pump?

Only after checking pressure, flow, current, port thread, installation space and the rating of all plumbing components.