Rickmeier R25/8 FL-Z Hydraulic Gear Pump

Rickmeier R25/8 FL-Z Hydraulic Gear Pump

The Rickmeier R25/8 FL-Z is an external gear pump engineered for continuous hydraulic, lubricating, and circulation services across heavy marine, offshore, and industrial power equipment. Designed and manufactured in Werdohl, Germany, the R25 series handles clean lubricating fluids, mineral oils, synthetic hydraulic media, and fuel oils across extreme viscosity gradients.

Built with an EN-GJL-250 (GG-25) pearlitic cast iron housing and case-hardened steel gear sets (16MnCrS5), the R25/8 FL-Z is specifically tailored to run under severe thermal and mechanical loads. The pump operates without external shaft leakage risks due to precision-machined mechanical face seals (GLRD) and internal hydraulic hydrodynamic balance. It provides a steady volumetric delivery of 8.0 cm³/rev, handling working pressures up to 25 bar and operating speeds up to 3600 RPM, making it a primary choice for auxiliary engine forced lubrication, marine reduction gearboxes, bearing cooling loops, and industrial test stands.

Model Details:

• Manufacturer: RICKMEIER GmbH
• Series: R25
• Displacement Size: 8 (nominal 8.0 cm³/rev displacement)
• Model Code Breakdown:
  • R25: Frame size 25 gear pump casing
  • /8: 8.0 cm³/rev theoretical volumetric displacement
  • FL: Flange-mounted design (Flanschausführung with ISO/SAE pilot spigot)
  • -Z: Cylindrical drive shaft journal with fitted drive key (Zylindrisches Wellenende mit Passfeder)
• Standard Manufacturer Part Number (MPN): R25/8 FL-Z (Common assembly numbers: 447771, 31530-R25-8, R25/8-FL-Z-W)
• Interchangeable Variants: R25/8 FL-Z-DB (with integrated direct-acting pressure limiting valve), R25/8 FL-Z-SO (special clearance design)

Technical Details:

Applications

• Main and standby lubrication oil circulation.
• Marine fuel delivery, booster systems, and heavy fuel oil (HFO/MDO) circulation loops.
• Hydraulic power packs, hydrostatic testing racks, and actuator feed lines.
• Oil-to-air and oil-to-water heat exchanger and filtration loop charging pumps.

Frequently Asked Questions

What is the exact displacement and output flow of the Rickmeier R25/8 FL-Z pump?

The Rickmeier R25/8 FL-Z has a nominal volumetric displacement of 8.0 cm³ per revolution. Driven by a standard 4-pole electric motor running at 1450 RPM, it delivers a flow rate of approximately 11.2 to 11.6 liters per minute at nominal operating pressures. Driven at 1750 RPM (60 Hz motor), output flow rises to roughly 13.8 liters per minute.

What do the designations “FL” and “-Z” mean in the Rickmeier model code?

FL” indicates a flange-mounted pump body (Flanschausführung) designed to mount directly to an electric motor intermediate bell housing, engine casing, or gear housing via a precision pilot spigot. The “-Z” suffix signifies a standard cylindrical drive shaft with a parallel drive key (Passfeder) conforming to DIN 6885.

Can the Rickmeier R25/8 FL-Z pump handle reverse shaft rotation?

Standard R25/8 FL-Z pumps are directional (predetermined as either Clockwise/Right-hand or Counter-Clockwise/Left-hand rotation). Operating in reverse moves fluid backward and will overpressurize the internal mechanical shaft seal. If your machinery runs in both directions (such as a direct-reversing marine main engine), specify the reversible variant (designated with suffix -W) featuring an integrated internal hydraulic shuttle valve.

What causes mechanical seal leakage on the Rickmeier R25 series pump?

Premature shaft seal leakage is usually caused by excessive vacuum on the inlet side (cavitation erosion), operating fluid containing abrasive metal debris exceeding ISO 4406 cleanliness limits, running the pump completely dry during commissioning, or angular/axial misalignment between the motor and pump shaft journals.

Is the Rickmeier R25/8 pump interchangeable with the R25/8 FL-Z-DB version?

Yes, in terms of mounting and port patterns, the casings are fully compatible. However, the “-DB” version includes an integrated, adjustable spring-loaded direct-acting pressure relief valve (Druckbegrenzungsventil) built into the pump top cover. If installing a standard R25/8 FL-Z without the DB valve, ensure your piping network contains an external inline system relief valve to protect downstream piping from overpressurization.