56A Variable-Speed DC Diaphragm Water Pumps
Water-pressure pumps with pressure-feedback speed control and source-listed open flow of18.9 L/min. Select 12V or 24V DC and the pump configuration with or without a 1 L accumulator. The family-reference photographs show the pump housing and package contents. Choose the correct voltage and package in the model selector, and confirm the actual nameplate before installation.
Options and Source References
| Model | DC supply | Current reference | Open flow | Maximum-pressure reference |
|---|
| SFDP1-050-070-56A | 12V | 10.0 A | 5.0 GPM /18.9 L/min | 70 psi /4.8 bar |
| SFDP2-050-070-56A | 24V | 5.5 A | 5.0 GPM /18.9 L/min | 70 psi /4.8 bar |
The source does not provide a complete pressure/flow curve or test conditions. Open-flow and maximum-pressure figures are separate references, not a simultaneous operating point. Current is a source-table reference, not a fuse or cable specification. The supplied feature artwork gives a1.8 m /5.906 ft suction reference without a full priming test method; actual performance depends on lift, hose restrictions, liquid and supply voltage. No indefinite dry-running or continuous-duty duration is established here.
Package Contents
The pump configuration is pictured with a 52S02 inlet strainer and41F004,41F003 and41F001 quick-connect fitting references. The accumulator configuration adds the original1 L tank and its two pictured tank fittings. Tank volume is the source-listed nominal vessel volume, not a promise of1 L usable drawdown. Hoses, wiring protection, mounting hardware, a battery and application vehicles are not included unless expressly shown as part of the selected package.
Original Pump Dimensions
| Reference | Metric | Calculated inches |
|---|
| Overall length | 215.5 mm | 8.484 in |
| Width reference | 136.4 mm | 5.370 in |
| Height reference | 126.47 mm | 4.979 in |
| Mounting references | 76.5 mm and99.0 mm | 3.012 in and3.898 in |
| Fixing-hole reference | 5.0 mm | 0.197 in |
The original engineering lines and original inch/mm labels remain in the drawing. Added conversions use25.4 mm per inch and three-decimal rounding; original labels may round differently. The drawing marks a 3/4in quick-attach connection. This is not a guarantee that every supplied fitting has an interchangeable3/4in thread or that a particular hose bore will fit. Confirm the actual mating fitting, mounting surface, hose and clamp before installation. No unprovided accumulator mounting drawing or tank dimension is inferred from the pump drawing.
Demand Control and Accumulator Use
The source describes an internal control circuit that adjusts motor speed in response to pressure demand. Connect only to the specified DC supply. The1 L accumulator provides a separate pressure-storage vessel in the selected package. Follow the actual tank label for pressure limits, charging and servicing. Keep its original warning label visible; do not set a precharge or charge/discharge it merely by copying a different tank model.
Installation and Maintenance
- Match the selected pump voltage to the DC system and check the actual nameplate. Isolate power before mounting or wiring.
- Secure the mounting feet to a supported surface using suitable fasteners without distorting the base. Provide access to the inlet strainer, fittings and electrical connections.
- Fit the strainer and the correct quick-connect fittings according to the actual pump instructions. Support pipework and avoid restricted, kinked or undersized suction lines.
- Wire with the actual polarity, conductor size and circuit protection specified for that model. The source table is not a complete electrical installation design.
- For the accumulator package, follow the tank instructions for orientation, charging and pressure settings. Depressurize and isolate the system before removing any tank fitting or servicing the vessel.
- Prime and test under supervision. Check leakage, automatic demand response, flow and electrical behaviour. Clean the strainer and inspect fittings, mounting feet and leads regularly.
Ordering and Application Check
The original boat and RV photographs illustrate water-system applications; they do not certify every installation. Fluid compatibility, drinking-water approval, ignition protection and particular vessel or RV certification are not established by these images. Do not use for flammable liquids; the original pump labels carry that warning. Confirm actual wetted materials, temperature limits, duty requirements, pressure settings and fitting compatibility if critical to the application.
Contact boltte@boltte.com for the selected model's installation information. Original product photographs, source performance table, dimensional drawing, accessories, accumulator warning and rear mounting/lead detail are retained below.










