Most of the catalog trades flow against pressure. You can have 40 GPM at 1,500 PSI or 8 GPM at 7,250, but not both. The RF series sits in the awkward, expensive middle: real volume at very high pressure, which is what surface prep and hydro-demolition actually need.

Four models, 5.8 to 10.3 GPM, all at 5,800 PSI, all at 1,450 RPM on a 30 mm solid shaft.

The four RF Series pumps

The crankshaft stamp is the quickest way to identify an RF pump already in service when the nameplate has been worn or painted over. Stamp 1 through 4 maps to 22, 27, 36 and 39.

All four have 1 in FNPT inlet and 1/2 in FNPT outlet, a brass head, bronze connecting rods, ceramic plungers, stainless valves and a 1.07 gallon crankcase.

Sizing the drive for RF pumps

This is where the RF series surprises people. EBHP is GPM times PSI divided by 1,460, and at 5,800 PSI the numbers get large fast. The RF22.400N needs 23 HP at the shaft. The RF39.400N needs 41.

Add 10 to 20 percent and you are specifying 30 HP for the smallest model in the range and 50 HP for the largest. That drives the electrical service, the starter, the panel and the skid, so settle it before anything else. A pump this size on an undersized motor will trip, stall or simply never reach rated pressure.

Why 1,450 RPM matters here

At 5,800 PSI, every component is already working hard. Running slowly is what makes the service life reasonable: fewer cycles per hour on the plungers, seats and seals, less friction heat, and gentler pulsation on a system where pressure spikes are genuinely dangerous.

The 1.07 gallon oil capacity is part of the same design. On continuous duty the oil is carrying the heat away, and volume is what keeps its temperature down.

Where the RF earns its place

• Surface prep: rust, paint and coating removal from bridges, steel structures and infrastructure
• Shipyards and marine: hull cleaning, barnacle removal, corrosion control, offshore maintenance
• Pipe and tank cleaning: oil, gas and wastewater, where flow restoration matters as much as pressure
• Mining and construction: heavy machinery, excavators and haul trucks in conditions that destroy lighter pumps
• Municipal: hydro-demolition, graffiti removal, large-scale infrastructure work
• Hydrostatic testing: supplying controlled high-pressure water for pipeline and vessel testing

What these have in common is that 3,000 PSI will not do the job and 8 GPM of it is needed to do the job at a sensible pace.

Safety at 5,800 PSI

This is not a bigger pressure washer. At this pressure water cuts skin without the operator feeling an impact, and injection injuries need immediate surgical attention.

Every component downstream must carry the rating with margin, including the quick couplers. Fit a primary relief valve, and a burst disc as a secondary on ultra high pressure builds. Operators need training specific to this pressure class, not general pressure washing experience.

RF pump maintenance

The RF is fully rebuildable. The wear parts are the valve kit, the Ø22 piston kit, the Ø22 water seal kit, the oil seal kit and the Ø22 piston guide kit. Confirm each against your model before ordering.

• Change the oil on schedule with SAE30 non-detergent. AR645107 is the 1.07 gallon container, which is exactly one fill.
• Replace seals and valves on an hours interval rather than after a failure. At this pressure a failed seal takes other parts with it.
• Watch inlet pressure and flow. Cavitation at 5,800 PSI destroys valve seats quickly.
• Keep the pump dry and clean in storage.

Maintained properly these run tens of thousands of hours, which is the reason they cost what they cost.

Browse the industrial pump range, or send your required flow and the motor you have available and you will get a model that your electrical service can actually support.