SEAFLO offers two popular diaphragm pump lines for fresh water systems: the compact 33 Series and the higher-flow 55 Series. Both are self-priming and on-demand, but they target different plumbing setups.
33 Series — RV & Standard Marine Galley
The 33 Series delivers 3.0 GPM at 45 PSI on 12V (or 110V/115V AC for shore power). It is the best-selling choice for RV sinks, showers, and small marine galleys where moderate flow is sufficient.
- 12V, 24V, and 110V models available
- Quiet operation with automatic pressure switch
- Pair with a SEAFLO accumulator tank to reduce pump cycling
55 Series — Washdown & High-Demand Systems
The 55 Series steps up to 5.5 GPM at 60–70 PSI. It powers deck washdown kits, larger RV plumbing runs, and applications that need higher volume.
- Available as standalone pumps or complete washdown kits with hose and nozzle
- 12V and 24V DC options
- Ideal for boat deck cleaning and multi-fixture RV layouts
Quick Comparison
| Spec | 33 Series | 55 Series |
|---|---|---|
| Flow | ~3.0 GPM | ~5.5 GPM |
| Pressure | 45 PSI | 60–70 PSI |
| Best for | RV sinks, small boats | Washdown, large RV |
| Voltage | 12V / 24V / 110V | 12V / 24V |
Which Should You Buy?
Choose the 33 Series for standard RV fresh water or a single-boat galley. Choose the 55 Series if you need a washdown system, run multiple outlets simultaneously, or want higher deck-cleaning pressure.
Not sure? Use our Product Finder or see the full comparison table.
