Sutorbilt

Sutorbilt is an industrial brand of positive-displacement (P-D) rotary-lobe blowers and vacuum pumps, known especially for the Legend series. These machines have been widely used across wastewater treatment, pneumatic conveying, chemical and general industrial air-handling systems.

History

Origins

The technology underpinning Sutorbilt blowers derives from early 20th-century rotary-lobe designs (often associated with the Roots Blower Company type). While a full corporate lineage is not always clearly documented, Sutorbilt units emerged as specification-grade P-D blowers used in demanding industrial environments.

Brand consolidation

The Legend series is described as having “more than 75 years” of development in the design and manufacture of P-D blowers.^[1] In the later 20th century, the Sutorbilt line (and related brands such as DuroFlow) became part of the Gardner Denver product family, which itself is now under the umbrella of Ingersoll Rand (and its successor entities).^[2]

Modern developments

In 2025, Gardner Denver announced the Legend Tri-Lobe series, a new variant of the Sutorbilt line with tri-lobe rotor geometry for reduced noise and smoother airflow.^[3]

Design and operation

The Sutorbilt design operates on the positive-displacement principle: two intermeshing rotors rotate within a precisely machined housing, trapping a fixed volume of air (or gas) and transporting it from inlet to outlet. This means the flow is volumetric, relatively independent of small changes in discharge pressure — a large benefit in many industrial applications.

features include:

• Cast-iron cylinder housing with integral ribs for rigidity and heat dissipation.^[4]
• Precision timing gears to synchronise the rotors and prevent contact.
• Lubrication systems: either grease/splash or dual-splash (DSL) to ensure bearings and gear-end lubrication over long load cycles.^[5]
• High-temperature seals (e.g., Viton) for reliable sealing in harsh environments.^[6]
• Universal mounting feet or flexible mounting options to allow installation in horizontal or vertical orientations.^[7]

Typical performance: Many Legend-series models are rated for pressures up to about 15 psi[g] and vacuums to about 16 inches Hg.^[8]

Product evolution and variants

Legend Bi-Lobe

The original Legend line features bi-lobe rotor geometry, strong construction and multiple sizes and configurations. According to Gardner Denver^[9], the Legend series has been described as “synonymous with quality and reliability” for over 75 years.^[10]

Legend Q (“Quiet Series”)

A quieter variant of the Legend line built for installations where noise reduction matters; uses improved porting or rotor geometry to reduce discharge pulsation.^[11]

Legend DSL (Dual Splash Lubrication)

Designed for heavy-duty continuous applications, the DSL variant offers a dual-splash lubrication system to improve bearing life and reduce maintenance and unexpected stops and failures.^[12]

Legend Tri-Lobe

The 2025-era advancement: tri-lobe rotor profile provides smoother flow, lower pulsation and reduced noise (claims of 3-5 dB reduction over bi-lobe). Rated up to ~972 cfm, ~13 psi[g] and vacuum to ~15 inHg for certain sizes.^[13]

Large-capacity series: 4500 / 8000

For high-capacity, higher-flow or higher-pressure systems, the Sutorbilt line (via Gardner Denver^[9]) offers series such as 4500 and 8000.^[14][15]

Applications

Sutorbilt blowers are widely deployed across industries who need their durability and predictable volumetric flow:

• Wastewater aeration systems: compressed air for biological treatment, back-wash and process air.
• Pneumatic conveying of bulk solids: grain, cement, plastic pellets, fly-ash, etc.
• Chemical, food, pharmaceutical processing: process air, vacuum handling, conveying of powders or granules.
• General industrial air-handling or vacuum pumping needs where continuous operation and reliability are essential.
• Retrofitting older installations: Because of their long production run, many legacy units remain in service; there is a large aftermarket for spares, remanufacturing and overhaul kits.^[16]

Legacy and aftermarket support

Because the Sutorbilt line has been manufactured for decades, many older units continue to operate in industrial installations. Aftermarket support includes:

• Repair and overhaul kits for broken or missing bearings, gears, seals and casings.^[17]
• Remanufactured or refurbished Sutorbilt blowers marketed by distributors.^[18]
• Technical support and service networks through Gardner Denver’s authorised distributors.^[19]