Allweiler SN 10-16

Common issues

• Mechanical seal leakage from wear or dry-running
• Screw/rotor clearance wear reducing volumetric efficiency and pressure
• Relief valve set-point drift causing bypass at the wrong pressure
• Bearing wear from misalignment with the driving motor
• Coupling wear/misalignment causing vibration and premature seal failure
• Air ingress at the suction side causing loss of prime or noisy running
• Fuel contamination (water, particulates) accelerating rotor and bushing wear

Inspection checklist

• Check the mechanical seal for leakage and correct flush/quench arrangement
• Measure discharge pressure and flow against nameplate/curve values
• Inspect coupling alignment between pump and driving motor
• Check the relief valve setting against the specified bypass pressure
• Inspect the strainer/suction filter for blockage
• Check the rotor/screw set for wear where accessible, or via performance trend
• Inspect the bearing housing for correct lubrication and abnormal noise/heat
• Verify baseplate and foundation bolts are tight with no excess vibration

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Mechanical seal kit
• Screw/rotor set (matched power rotor and idler rotors)
• Relief valve
• Coupling flexible insert
• Bearing set
• Gasket/O-ring kit

Safety

• Fuel service pumps handle flammable liquid under pressure - check for leaks before and during operation, no ignition source nearby
• The relief valve must be correctly set and tested - an incorrectly set valve risks overpressure of the fuel line
• Isolate and depressurize before opening the pump casing

Class survey

Fuel oil transfer/service pumps are within the general machinery survey scope; class will look for correct relief valve function, leak-free operation and, where duplicated, that the standby pump is proven operational. Keep pressure/flow trend records to support condition-based maintenance evidence.