What Is a STEIMEL Gear Pump?

A STEIMEL gear pump (KB series such as the KB 100-IIPR-DN40) is a positive-displacement pump where two meshing gears trap fluid in the tooth spaces and carry it from inlet to outlet. It delivers a near-constant flow proportional to speed, making it ideal for lubrication, cooling-oil circulation, transfer and low-pressure hydraulic duties.

Selection Checklist

• Flow and speed: Gear pumps are flow-at-speed devices — pick displacement (cc/rev) and the drive RPM to hit the required L/min.
• Pressure rating: Confirm continuous and peak pressure; the KB range covers low-to-mid pressure transfer and lubrication.
• Viscosity range: Gear pumps handle a wide viscosity band, but very high viscosity needs lower speed and a larger port (DN40 here) to avoid cavitation.
• Sealing: Mechanical seal vs lip seal — mechanical seals suit higher pressure and cleaner fluids.
• Rotation and porting: Define clockwise/counter-clockwise and inlet/outlet positions to match the skid layout.

Installation Guidelines

1. Always prime the pump before start-up; running dry scores the gears and bushings quickly.
2. Provide a suction strainer (recommended 100–150 µm) and keep suction lines short, large and leak-tight to prevent cavitation.
3. Align the coupling to avoid side-loading the shaft; use a flexible coupling and support the motor independently.
4. Fit a pressure-relief valve on the discharge for systems without a fixed restriction.

Operation and Maintenance

Monitor for rising noise (cavitation or worn gears), higher current (internal wear) and external leaks at the seal. Change the fluid and filter on the manufacturer interval, and keep the relief valve set above normal operating pressure but below the pump maximum. Store spares (seal kit, coupling) for critical lube-oil loops.

Troubleshooting

• Low flow: air in suction, clogged strainer, worn clearances or wrong rotation.
• Overheating: dead-headed discharge without relief, or excessively high viscosity at low temperature.
• Seal leak: shaft wear or contamination — replace seal and check fluid cleanliness.