Allweiler AFI10 R38G19US-W197H Triple Screw Pump

Allweiler AFI10 R38G19US-W197H Triple Screw Pump (Mfg. 2016) – New Surplus

The Allweiler AFI10 R38G19US-W197H is a self-priming triple screw positive displacement pump engineered specifically for marine fuel delivery systems, auxiliary boilers, and forced industrial lubrication circuits. Manufactured under the ALLFUEL® program by CIRCOR Allweiler in Radolfzell, Germany, this 2016 unit is preserved in New / Unused Surplus condition.

Tri-screw architecture provides virtually pulsation-free displacement. The assembly features one hydraulically balanced power rotor (drive spindle) interlocking with two symmetrical, hydraulically driven idler rotors running inside an exchangeable casing insert. Because torque transfer is governed entirely by fluid dynamics within closed screw chambers, the thread flanks operate free of direct mechanical driving friction, maximizing wear life even when handling low-viscosity Marine Gas Oil (MGO) or high-temperature Heavy Fuel Oil (HFO).

Technical Details:

Features

1. Balanced Hydraulic Design with Hydrodynamic Balancing: The main driving screw incorporates an integral hydraulic balancing piston, channeling return fluid back to the suction side. This eliminates axial bearing loads and isolates the mechanical seal strictly to inlet pressure levels.
2. Extreme-Hardness SiC/SiC Mechanical Seal: Configured with silicon carbide versus silicon carbide running faces backed by FKM secondary seals. This arrangement prevents thermal deformation and abrasive cutting when handling desulfurized ultra-low-sulfur marine gas oil (DMA/DMB).
3. Modular Cartridge Insert Assembly: The liner, idler spindles, driving spindle, and seal face are contained in a single replaceable insert core. Overhauls can be performed in place without disturbing rigid system piping.
4. Integral Spring-Loaded Bypass Valve: Protects downstream flowlines, flow meters, and fuel injector rails against pressure shocks caused by rapid solenoid shutoffs.
5. Fluid-Damped Smooth Flow Profile: Continuous volumetric displacement eliminates fluid shearing, foaming, and cavitation pulses, protecting inline viscosity sensors and burner nozzle tips.

Applications

• Auxiliary Marine Boiler Fuel Injection: Feeder and burner firing pumps handling Marine Diesel Oil (MDO), Low Sulfur Heavy Fuel Oil (LS-HFO), and Marine Gas Oil (MGO) on cargo vessels, tugs, and offshore platforms.
• Diesel Engine Fuel Conditioning Modules: Booster and supply units for Wärtsilä, MAN Energy Solutions, and Caterpillar/MaK 4-stroke auxiliary gen-sets.
• Separation & Purifier Feed: Metered delivery to fuel centrifuges, settling tanks, and waste oil recovery separators.
• Turbine & Gearbox Forced Lubrication: Supplying low-pulsation lubricating oil directly to reduction gears, stern tube seals, and heavy turbomachinery bearings.
• Industrial Oil Hydraulics: Hydraulic lift skids, hydraulic ring mains, and machine tool fluid circulation up to 40 bar.

Pre-Commissioning & Startup Protocol

• Never Run Dry: Three-screw pumps rely completely on the handled medium for internal plain-bearing and spindle flank lubrication. Always prime the pump casing manually through the venting plug (E7) before energizing the motor. Running this unit dry for even 10 seconds will score the aluminum casing insert.
• Direction of Rotation: Confirm motor rotation matches the casing arrow (Clockwise rotation when looking directly at the pump drive shaft). Reverse rotation will pressurize the mechanical seal chamber beyond design tolerances, leading to instantaneous seal failure.
• Viscosity Management with MGO: When switching from heated HFO to cold MGO, verify minimum fluid viscosity remains strictly above 1.2 cSt at operating temperature. If handling low-sulfur marine gas oil, verify the fuel cooler maintains fuel temperature low enough to preserve dynamic film thickness across the idler screws.
• Relief Valve Verification: The “H” spring is factory set for elevated differential pressures. Before placing into a burner loop, crack the pressure gauge ports (M1/M2), bring the fluid up to operating temperature, and verify bypass cracking pressure does not exceed system line ratings.

Frequently Asked Questions

Can this AFI10 pump handle Low-Sulfur Marine Gas Oil (LSMGO)?

Yes. The AFI10 R38G19US-W197H features silicon carbide vs. silicon carbide (US) mechanical seal faces and an internal fluid-lubricated bearing arrangement engineered to maintain hydraulic boundary layers down to 1.2 mm²/s.

Is this pump supplied with an electric drive motor?

This listing is for the bare-shaft pump unit with shaft key and flange face. It is ready to bolt directly onto an IEC standard B5/V1 bell housing. Complete pump-and-motor skids (400V/440V, 50Hz/60Hz marine-certified motors) can be assembled upon request.

What is the difference between an AFI and an SPF series pump?

The AFI (ALLFUEL) series is an evolution of the SPF series. It features a standardized one-piece cartridge insert design and upgraded mechanical seals specifically optimized for both high-viscosity fuels and modern low-viscosity, low-sulfur marine distillates.

Can the internal relief valve be vented externally?

No. The integrated relief valve discharges internally back into the suction chamber. If continuous bypass operation is expected for extended durations, an external circulation valve piped back to the day/settling tank must be installed to prevent fluid overheating.