Choosing the right gear pump comes down to the liquid and the duty. Get these points right and a gear pump will run for years. Get them wrong and the gears and seals wear out fast.
1. Define the Liquid
- Viscosity. Gear pumps handle thin to very thick liquids. Thick liquids slow the pump down and need more suction head and power.
- Lubricity. The liquid lubricates the gears. Oils and resins are ideal. Thin, non-lubricating liquids wear metal gears quickly.
- Solids and abrasives. They wear the clearances, so avoid gear pumps when the liquid carries them.
- Temperature. It affects viscosity, clearances and material choice.
2. Define the Duty
- Metering or transfer. Metering needs steady speed control and tight repeatability. Transfer needs flow and reliability.
- Flow and pressure. Positive displacement means flow is proportional to speed, and pressure comes from the system.
- Suction conditions. Check available suction head and line size, especially with viscous liquids.
3. Choose External or Internal
External gear pumps suit higher pressures and clean liquids. Internal gear pumps are gentler, handle a wider viscosity range and need less suction head. Our guide to external vs internal gear pumps covers the trade-offs.
4. Pick Materials and Sealing
Cast iron suits many oils. Stainless steel and chemical-resistant materials suit corrosive liquids. For toxic or hazardous liquids, a sealless magnetic drive design avoids a shaft seal that can leak. See our sealless pumps page.
5. Protect the Pump
- Fit a relief valve, because blocked discharge overpressures a gear pump
- Protect against dry running
- Use a strainer upstream to catch solids
- Use a variable frequency drive where flow must be adjusted
Power Energy supplies gear pumps, including gear metering and transfer pumps from Pompe Cucchi, across Saudi Arabia and the GCC.
Talk to Power Energy
Send us the liquid, viscosity, flow, pressure and duty. Call or WhatsApp +966 56 278 9535 or email sales@powerenergy.com.co.