Gear Pump vs. Lobe Pump: Which One Is Right for Your Application?

Both gear pumps and lobe pumps fall under the positive displacement family, meaning they move fluid by trapping a fixed volume and forcing it through the discharge. But beyond that shared principle, they’re built for very different jobs and understanding the distinction can save you from a costly misspec.

First, Let’s Talk Gear Pumps: Internal vs. External

This is where it gets a little more nuanced, and it’s worth knowing the difference.

External gear pumps use two externally meshing gears rotating in opposite directions. They’re simple, robust, and well-suited for high-pressure applications with clean, non-abrasive fluids.

Internal gear pumps like the ones made by Viking Pump, one of our trusted manufacturers, use a drive gear rotating inside a larger idler gear. This design is exceptionally smooth, handles a wide viscosity range, and is ideal for lubricating oils, fuel oils, resins, adhesives, and other high-viscosity fluids. The internal gear design also tends to be gentler on the fluid, making it a go-to in many industrial process applications.

Now, Lobe Pumps

Lobe pumps like the rotary lobe pumps made by NETZSCH, another key partner of ours, operate on a similar positive displacement principle but use two synchronized lobes that rotate without contacting each other. This non-contact design means:

• No metal-to-metal wear on the fluid path
• Low shear, great for shear-sensitive products
• Easy to clean and sanitize (CIP/SIP capable)
• Handles solids, slurries, and high-viscosity products with high-solid content

That’s why lobe pumps are the standard in sanitary and food-grade applications like dairy, beverage, pharmaceuticals, and wastewater biosolids.

 

So, Which Do You Need?

Still not sure which one fits your process? That’s what we’re here for. Our team at Wood Equipment Company has the application experience to help you spec the right pump the first time.

📞 804-798-8844 | 📧 sales@woodequip.com | woodequip.com