What’s the Difference Between a Vacuum Pump and a Blower?

Yep. I’d change grease → flammable materials anywhere we mention typical applications, and update the blower section to specifically cover Roots-style, straight-style, and helical tri-lobe-style blowers.

What’s the Difference Between a Vacuum Pump and a Blower?

If you work around vacuum trucks, tank trailers, or other liquid-handling equipment, you’ve probably heard the terms vacuum pump and blower. Both can be used to create vacuum and move air, but the way they operate is very different.

One of the biggest differences is what is happening inside the unit. A rotary vane vacuum pump has internal components that make contact and require lubrication, while the lobes inside a positive displacement blower do not touch each other.

Understanding these differences can help you determine which type of equipment is better suited for your application.

How a rotary vane vacuum pump works

A rotary vane vacuum pump uses a rotor with sliding vanes inside the pump housing. As the rotor turns, the vanes maintain contact with the inside of the housing, creating chambers that change in volume and move air through the pump.

Because there is contact inside the pump, lubrication is extremely important. Oil helps lubricate the internal components, reduce friction, control heat, and protect the pump from excessive wear.

This also means an oil-lubricated vane pump will discharge some oil or oil mist through the exhaust during operation. Depending on the application, an oil catch muffler or other equipment may be used to help collect that oil.

Rotary vane vacuum pumps are commonly used on vacuum trucks and trailers handling septic waste, wastewater, flammable materials, and other liquids.

Common examples include Fruitland 500 and 870 pumps along with many National Vacuum Equipment (NVE) vacuum pumps.

How a blower works

A positive displacement blower operates differently.

Inside the blower are rotating lobes that are precisely timed so they move extremely close to one another without actually touching. The lobes also do not make contact with the inside of the air chamber during normal operation.

Because there is no contact between the lobes in the air chamber, oil is not required inside that portion of the blower for lubrication. The bearings and gears still require lubrication, but that oil is kept separate from the air stream.

Because of this design, a blower does not normally discharge oil through the air stream like an oil-lubricated rotary vane vacuum pump does.

There are several different blower designs used depending on the application, including Roots-style, straight-style, and helical tri-lobe-style blowers.

Blowers are commonly used when an application requires higher airflow, continuous operation, or the movement of dry material.

So, what’s the main difference?

One of the easiest ways to understand the difference is to look at what is happening inside each unit.

In a rotary vane vacuum pump, the vanes make contact with the pump housing. That contact requires lubrication, which is why oil is such an important part of operating and maintaining a vane pump.

In a positive displacement blower, the lobes are timed so they do not touch each other. Since there is no contact inside the air chamber, oil does not need to be introduced into the air stream.

There are also differences in airflow, vacuum capabilities, operating characteristics, and the types of jobs each unit is best suited for.

A vane pump is commonly a great fit for liquid waste, flammable materials, and vacuum tank applications where strong vacuum performance is needed.

A blower is often better suited for applications requiring higher airflow, longer operating periods, or dry material handling.

Neither option is automatically better than the other. It comes down to what the equipment needs to do.

Maintenance is important for both

Although they operate differently, both vacuum pumps and blowers still require proper maintenance.

For vane pumps, oil level and condition are extremely important along with vanes, bearings, seals, and internal wear. Operating a vane pump without proper lubrication can quickly cause serious damage because of the internal contact taking place inside the pump.

Blowers also require maintenance even though the lobes themselves do not touch. Bearings, gears, seals, filters, and oil levels in the lubricated sections of the blower should all be properly maintained.

Unusual noises, excessive heat, loss of vacuum or pressure, and reduced performance can all be signs that something needs attention.

Which one is right for your application?

Choosing between a vacuum pump and a blower depends on what you're trying to accomplish.

The material you're moving, required airflow, desired vacuum or pressure, operating time, and truck or trailer setup can all affect which option makes the most sense.

If you're unsure which one you need, Meters Inc. can help.

We sell new and professionally rebuilt vacuum pumps and blowers and provide rebuild and repair services for equipment from manufacturers including Fruitland, National Vacuum Equipment, Roots, Hibon, and more.

Whether you need a replacement unit, need your current pump or blower rebuilt, or have questions about your setup, contact Meters Inc. and we'll help you find the right solution.