The RTX is the top of AR’s industrial range, and it comes two ways. You can buy the pump alone and drive it yourself, or you can buy an RTX hydraulic drive pump already coupled to a Sauer Danfoss hydraulic motor. The decision depends on whether you are building a system or installing one.

Either way the range covers 8 to 39.6 GPM and 1,450 to 4,350 PSI, all at 1,450 RPM.

Direct drive pumps, for builders

The SX suffix on the RTX70 marks the left-hand shaft version, for mirrored installations where the motor has to sit on the other side.

Hydraulic motor packages, for installers

There are also WC variants (HYD-RTX30WC, HYD-RTX70WC) and the HYDM-DF-044 44cc Danfoss motor if you are building the pairing yourself.

Sizing the drive properly

EBHP is GPM times PSI divided by 1,460, and at RTX pressures the numbers are large. The RTX60-DD needs 47 HP at the shaft. The RTX85-DD needs 46. The RTX150 needs 39 even at only 1,450 PSI, because 39.6 GPM is a lot of water.

Whatever drives the pump, motor, engine or hydraulic circuit, has to deliver that with margin. On the hydraulic packages, check your circuit’s available flow and pressure at working temperature rather than the machine’s brochure figure. A hydraulic system that made its rated flow when new may not now, and a starved motor turns the pump slowly, which looks like a bad pump and is not.

How RTX hydraulic drive pumps are built

• Head: nickel-plated brass, for aggressive water
• Connecting rods: aluminium
• Plungers and valves: stainless
• Crankcase: 76 oz oil capacity
• Speed: 1,450 RPM
• Ports: 1 in F inlet, 1/2 in F discharge

The 1,450 RPM and the 76 oz crankcase go together. At this size the oil is doing most of the cooling, and running slowly is what keeps a pump this loaded alive for years rather than seasons.

Which RTX hydraulic drive pump configuration to choose

Buy the direct drive pump if you are an OEM or a skid builder, you already have a motor or gearbox specified, and you want to control the coupling and the layout. You take on the alignment, and alignment is what kills hydraulic installations done by eye.

Buy the hydraulic motor package if you are fitting a pump to an existing machine that already carries hydraulics. The pairing is done, the alignment is done, and you are plumbing rather than engineering.

Where RTX hydraulic drive pumps are used

• Oil and gas: drilling rigs, offshore platforms, washdown skids
• Mining and quarrying: dust suppression, conveyor cleaning, equipment wash bays
• Municipal: sewer jetting, wastewater treatment, street cleaning
• Fleet and rail: train wash stations, truck depots, transit
• Industrial plants: descaling, process washdown, food plant sanitation
• Marine: dockside cleaning and hull maintenance

Servicing RTX hydraulic drive pumps

• Keep the crankcase topped with non-detergent SAE30. At 76 oz, check it rather than assuming.
• On hydraulic installations, watch circuit temperature. Overheating shows up in the hydraulics before it shows up in the pump.
• Replace seals and valves on an hours interval using AR rebuild kits, not after a failure.
• Re-torque mounting bolts after the first run hours, then periodically. Vibration and misalignment are the same problem seen twice.
• Filter the supply water. At these flows, unfiltered water moves a lot of grit through the valves.

Browse the full hydraulic pump and motor range, or send your circuit’s flow and pressure and you will get a configuration your machine can actually drive.

Reference: Hydraulic Institute.