With the right modifications, this technology can handle heat and viscosity variability.
by Nicholas Ortega
April 19, 2018

Sometimes referred to as coating asphalt, filled asphalts can have limestone or other abrasive particle concentrations of 60 to 70 percent, making them heavily abrasive. Pumps in these applications generally require hardened cast-iron or tungsten-carbide bushing sets and hardened case, head, rotor gear and idler gear. Like all pumps used in abrasive applications, the pump speed should be reduced significantly to maximize the life of its components.

The Solution

The ultimate—and necessary—solution for pumping asphalt is to use a pump that features a heating jacket, robust gear materials, a wide range of internal component material options and flexible sealing configurations.

Image 2 internal gear pumpsImage 2. Internal gear pumps feature a series of design enhancements that make them ideal for handling asphaltic products with a wide range of temperatures and viscosities. These include a large jacketed surface on the pump case and pressure relief valve, jacketing behind the pump rotor, a rotatable casing and high-strength, ductile-iron gear material.

The key to one successful asphalt pump’s operation is a heating jacket that provides these standard-setting features to the operator: a jacket surface area on the pump case and pressure relief valve (PRV) that enables more uniform pump heating whether using steam or hot oil jacketing placed behind the pump rotor, which eliminates a known cold spot that can lead to hard startups and premature pump and seal failuresability to use a jacketed head and PRV simultaneously rotatable casing that allows the operator to use both right-hand and left-hand flange orientations as needed without additional lead times standard high-strength, ductile-iron gear material that improves reliability when compared to steel rotors, all while resulting in purchase-cost savings that can be as much as 25 percent

In addition, these pumps have been designed to be the world’s first drop-in replacements for competitive models. Components are also part-for-part interchangeable with one competitive model with very specific design enhancements where required to improve reliability.

The design also builds on the features of the manufacturer’s other internal gear pump models: compatibility with packed-gland, mechanical and triple-lip seals, ability to repair or replace seals without taking the pump out of service, idler gear that is driven by the rotor/shaft assembly, reversible rotor/shaft assembly that allows pumping in any direction

Conclusion

Asphalt has proven over time to be one of the world’s most irreplaceable commodities and has played a pivotal role in the development of numerous civilizations. There is no question that asphalt will continue to play a prominent role in the future, and there will be challenges that come with handling and transferring it. That is why internal gear pumps are such a critical option for the industry.

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