Crane's Fluid Connection Blog | Fluid Handling Tips

How Can You Get More Flow Out Of A Gear Pump?

Written by Crane Site | December 2, 2015

Gear pumps (or positive displacement pumps) displace a specific volume of fluid per revolution of the shaft. When the shaft spins faster, you get more volume of liquid out of the pump.

Standard motor speed designs are 3600 RPM, 1800 RPM, and 900 RPM. But, gear pumps operate at much slower speeds than these standard motor speeds, oftentimes below 800 RPM.

But, how do you get more flow in less time from a gear pump? Because let’s be honest, time is money!

One option is to install a larger pump and utilize a Variable Frequency Drive (or VFD), gear reducer, or combination of the two as an add-on to the pump, which are designed to control pump operating speed. Or, you can take advantage of newer gear pump technology that is smaller, and specially designed to give you more flow because of increased operating speeds.

LARGER PUMP WITH GEAR REDUCERS AND/OR VFDS

Gear reducers are commonly used to reduce standard drive speeds to match pump application requirements, while increasing the amount of torque per revolution of a shaft. VFDs are another form of an adjustable speed drive used to control motor speed and torque. You can utilize one or the other, or a combination of the two. 

Downside to this option?

There's more equipment to maintain, larger pumps usually carry a hefty price tag, and there's more costs in general because of the additional equipment. Not to mention the footprint required for all of it!

NEWER GEAR PUMP TECHNOLOGY

If you're like most maintenance professionals, additional space and time to maintain extra pieces of equipment aren't easy to come by. Therefore, you may want to look at some of the newer gear pump designs available.

One that we typically recommend for increasing flow is Viking Pump's motor speed design series. It’s specially made to operate at higher speeds (than a regular gear pump would experience) without using a VFD or gear reducer, giving the operator more flow in a smaller footprint. 

When more flow is required for an application to keep it moving, like chocolate or other high viscosity fluid, a larger pump might be desired, but larger pumps cost more. Now, more flow can be obtained from a smaller-scale gear pump in a smaller footprint. 

These are just some of the most common ways to increase flow with gear pumps. If you need help finding the right method for your application, contact an engineer in your area to help. Their expertise will help you find what you need faster, and may help save you money in the long run. 

If you’d like to take an in-depth look at the positive displacement pumps in your facility, ask our engineers. There may be opportunities to increase flow without a larger pump, or gear reducers and VFD's. We’re happy to help businesses in Wisconsin and upper Michigan.