Bitumen pumps

Why bitumen needs a heated gear pump

Bitumen is solid at room temperature. To flow through a pipe it must be held, depending on the grade, between 150 and 180 °C. At that temperature it moves freely, but one cold spot inside the pump body is enough for it to set between the teeth and lock the gears at the next start-up. A centrifugal pump, moreover, loses almost all of its head with a fluid this thick.

That is why our bitumen pumps are self-priming external gear pumps: the flow stays constant whatever the back pressure, the pump primes on its own and the bitumen itself lubricates the internal surfaces, improving the volumetric seal as viscosity rises. On the CR series the heating jacket wraps the whole pumping chamber, so there is no cold zone where the product can crystallise.

Which series to choose for hot bitumen

• CR series — jacketed pump for bitumen with little or no abrasive filler, pitch, compounds and bituminous mixes. Ten models from 30.7 to 2,812 l/min at 950 rpm. The jacket runs on thermal oil, steam or superheated water. See the CR series.
• SEF version — for filled bitumen with medium to high filler content: support bearings outside the pump body, external timing gears in an oil bath and four gland packings that can be replaced on site.
• SB series — self-priming pumps that flange directly onto the tank of a bitumen sprayer, with two built-in valves for loading, recirculation, spraying and transfer. From 57 to 1,093 l/min.
• NAV series — for heavy fuel oil, thermal oil and bitumen emulsion that do not need a jacket. Flanged ports from DN 40 to DN 125.
• ZV series — small flows for thermal oil circuits and for dosing additives and fluxing agents, flanged directly to the motor.

How the pump is kept hot

Where the plant has a thermal station, the classic answer is the heating jacket connected to the thermal oil or steam loop. Where there is no boiler, or the pump sits far from the plant, we offer two alternatives:

• electric cartridge heating: a standard pump without jacket, two to four cartridges inserted in the pump body, a probe and an electronic temperature controller. The pump is up to temperature in about two minutes and the heat is generated exactly where it is needed;
• self-contained hot-spot heating: the CR jacket is filled with thermal oil heated locally by electric elements of up to 900 W, with an auxiliary 8 ZV circulation pump, a precision thermostat and an expansion tank. No boiler, no permits, no boiler maintenance.

In every case the pump must be insulated: without lagging, heat loss defeats any heating system, and the hot-spot version needs a few hours of preheating before the first start.

Typical applications for bitumen pumps

• Transfer of hot bitumen from road tanker to storage tank and feeding of asphalt mixing plants, where an asphalt pump runs for hours at constant flow.
• Recirculation of polymer-modified bitumen to prevent stratification in the storage tank.
• Loading, spraying and recirculation on bitumen distributors and emulsion sprayers, with the SB series flanged to the tank.
• Dosing of bitumen and additives in plants producing bituminous membranes and waterproofing sheets, using the CR in dosing mode with an inverter.
• Pumping of pitch, compounds and waxes with the same jacketed principle used for hot bitumen.
• Thermal oil circulation on the heating loop itself, using the NAV series or the ZV series.

What we need to size your bitumen pump

To propose the right model we need a few facts: type of bitumen (straight-run, polymer-modified, oxidised, filled and the filler percentage), working temperature, required flow in l/min or m³/h, discharge back pressure, heating medium available for the jacket (thermal oil, steam or none) and the type of drive. Every pump leaves our Bologna factory with ISO 9001:2015 quality control, and ATEX documentation is available for hazardous areas.

Send us these details on WhatsApp or through the quote form: you will get a technical proposal with model, motor and heating system, not a catalogue. If your fluid is not bitumen but another thick product, start from our viscous fluid pumps page.