A gear pump moves fluid between rotating gears and the pump casing. It gives steady flow with little pulsation, copes well with thick and lubricating fluids, and is widely used for chemical transfer and metering in industrial plants.
External and internal gear pumps
- External gear pump: two identical gears mesh side by side. Fluid is carried around the outside of the gears from suction to discharge. Simple, compact and good for higher pressures.
- Internal gear pump: a smaller gear turns inside a larger ring gear, with a crescent-shaped divider between them. Quiet, with gentle handling and good suction, and well suited to viscous fluids.
Where gear pumps are used
- Transfer of oils, resins, polymers, adhesives and additives.
- Continuous metering of viscous chemicals at a steady flow.
- Lube oil and fuel oil duties.
- Loading and unloading of viscous products.
Magnetic-drive gear pumps
In a magnetic-drive (sealless) gear pump, the motor turns an outer magnet that drives an inner magnet through a sealed can. There is no shaft seal, so there is no seal to leak. This suits toxic, hazardous or expensive fluids. They need clean fluid without solids, and they must not run dry.
What to check before you choose one
- Viscosity. Gear pumps handle thick fluids well. Very thin fluids can slip past the gears and reduce accuracy.
- Cleanliness. Solids and abrasives wear the gears and clearances quickly.
- Materials. Choose casing, gears and seals for the fluid. Stainless steel, cast iron and special alloys are common.
- Pressure and flow. Flow is proportional to speed, and a relief valve is needed on the discharge.
- Sealing. Mechanical seal or sealless magnetic drive.
Power Energy Gulf supplies Pompe Cucchi gear and magnetic-drive metering pumps and gear transfer pumps in Saudi Arabia and the GCC. See our dosing and metering pumps page, the positive displacement pump guide and the guide to types of pumps.
Tell us the fluid and duty. Contact us with your fluid, flow and pressure details and we will recommend a suitable pump.