asphalt pumps

Sometimes mined, but most often manufactured, the transportation and handling of asphalt is a challenging enterprise. Asphalt in the latter form is a carefully extracted residue resulting from the distillation process of selected crude oils like petroleum. As difficult to work with as it is versatile, it’s a sticky, often chemically aggressive media, a highly viscose liquid material requiring reliable, safe and knowledgeable handling. For asphalt to be pumped and transported it must be heated and maintained to between 300 and 350 degrees Fahrenheit (149 and 176 degrees Celsius), with temperatures dictated by its mix of asphalt, sometimes called bitumen, and additional mineral aggregates. It takes a versatile pump to convey such a complex, challenging product, but Netzsch NOTOS™ Multiple Screw Pumps (MSP) are uniquely suited to the job.


In the United States today, the most common use of asphalt is on roads and sidewalks, with 85 percent of it employed for paving surfaces. It’s also routinely used to make roof shingles, printers ink, lubrication oils, waterproofing materials, and medicines. Pumps specially made for asphalt conveyance, either after the distillation process or during the mining process, must be intelligently engineered to handle its unique composition and characteristics. Netzsch’s NOTOS MSPs are required to reliably move low to high viscosity media—everything from light fuel oil to viscous asphalt. These pumps are constructed with housing jackets protecting the mechanical steel so that when hot steam is added to maintain the asphalt media’s temperatures in an idle pump, their steel base remains intact and functioning smoothly.

Multiple Screw Pumps

Featured: The 4NS is designed and manufactured to convey a wide range of viscosities.
Above: Netzsch Notos™ Multiple Screw Pumps are manufactured to handle high viscosity.


Two Netzsch NOTOS Multiple Screw Pumps are manufactured using wear-resistance materials specifically designed to handle the robust wear and tear of transporting a semi-abrasive material like asphalt: the 2NS and 4NS. The 2NS, a two-screw pump, is suitable for light to heavy lubricating materials with medium to high viscosity. It has a maximum capacity of 2200 gallons a minute and a maximum pressure capability of 236 PSI. A robust, cartridge designed pump, its housing design is constructed of fabricated steel, and the entire outside diameter of the pump is heated. That’s important because the full housing heating jacket maintains a good flow of heat to the seal chamber—reducing opportunities for mechanical seal problems sometimes found in competitor’s pumps. Additionally, the 2NS pumps, and all NOTOS MSP pumps, reduce the potential for seal leakage. Hydraulically balanced, the 2NS offers quiet, pulsation-free flow and a reliably long lifetime of service.

Netzsch’s NOTOS 4NS model, a higher capacity pump, gets the job done faster. That makes it a popular choice to handle big assignments like the on-and-off loading of asphalt on ships in port. The faster the material can be moved, the less the overall dock time, translating to higher savings for the shipper. An externally timed, four-screw pump, the 4NS is designed and manufactured to convey a wide range of viscosities. The pump is a non-contacting design, which means there is zero contact between the flanks of the screws, or between the outside diameter of the screw and the inside diameter of the liner.

The 4NS is a beast of a pump, able to pump a wide range of viscosities, from 50 percent gas, with no modifications to the seals, to 50,000 cst oil, so it is a high capacity, high pressure, problem solver. Engineered to manage low to high viscosity, the 4NS can pump lightly abrasive products. Both the 2NS and the 4NS operate at a nominal motor speed, eliminating the need for a gearbox or V belt drive, and are backed by a generous three, year manufacturer’s warranty.


Already an attractive choice for handling difficult materials like asphalt, the 2NS MSP line also delivers substantial energy savings. Netzsch’s High Efficiency Unique Design (HUED) also features a cartridge design, and complete housing jacketing. Bushings supporting the screw’s outside diameter allow zero contact between screws and the liner, reducing wear while minimizing the need for costly maintenance and repairs. Users can lower the temperature of their asphalt by 25 degrees Fahrenheit, a dramatic 7 percent energy reduction, as compared to using a centrifugal, gear or sliding vane pump. What does that mean in savings? In a three-million-gallon, 3-inch insulated tank, that 25-degree reduction translates to energy savings of roughly $40,000 a month. A three million gallon non-insulated tank would see an astonishing $120,000 per month in energy savings!


Quality engineered and manufactured to the highest standards, Netzsch MSPs have been answering asphalt challenges for thirty-five years, effectively reducing the costs of ownership by delivering product reliability that minimizes expensive maintenance and extends service life. Whether the asphalt conveyance is for rail car on-and-offloading, tank-to-tank transfer, ship transport, or any other challenging application, Notos MSPs are built to operate efficiently, reliably and safely while consuming less energy. υ

About the Author

Jeffrey Bye is the director of customer relations, engineering, and projects at Netzsch Pumps North America, LLC. The Netzsch Group is a worldwide active family-owned enterprise with its headquarters located in Selb/Bavaria. Thirty-five companies in Europe, North America, South America, and Asia; fifty-four sales and service offices; and 158 agencies highlight the international profile. For more information, visit

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