Why bitumen emulsion needs a gentle, steady pump
Bitumen emulsion is bitumen dispersed in water. It is handled at temperatures far below those of hot bitumen, so a heating jacket is rarely needed, but the emulsion has a weakness of its own: it can break. Strong shear, turbulence and pulsating flow separate the bitumen from the water, leaving a product that clogs nozzles and filters and no longer bonds to the aggregate.
A positive displacement external gear pump moves the emulsion in a regular stream, with a flow that is proportional to speed and almost free of pulsation. This regular flow avoids breaking the emulsion, which is why the same principle is used on sprayers, distributors and transfer lines alike.
Which bitumen emulsion pumps to choose
- SB series — the emulsion sprayer pump by design: it flanges straight onto the tank of fixed or mobile bitumen distributors, with two built-in valves that give four functions: loading from an external source, internal recirculation, pressurised spraying to the rear spray bar and bypass transfer between tanks. Five models from 57 to 1,093 l/min.
- NAV series — flanged pumps from DN 40 to DN 125 for emulsion plants, loading bays and storage farms, supplied without jacket as standard. Nine models from 54 to 2,770 l/min, suited to continuous duty.
- ZV series — compact dosing pumps flanged to the motor, for small sprayers, laboratory units and the dosing of emulsifiers and additives with an inverter. Ten models from 0.47 to 102 l/min.
Pumps for emulsion sprayers and bitumen distributors
On a bitumen distributor the pump must do more than spray. With the SB series mounted on the tank you avoid long suction lines, which means less heat loss on hot products and less risk of cavitation. The two incorporated valves, manual or motorised, let the operator switch between loading, recirculation, spraying and transfer without extra pipework or additional valves.
Internal recirculation keeps the emulsion homogeneous during transport and, when the same vehicle is used for polymer-modified bitumen, prevents stratification in the tank. The integral heating circuit, connected to thermal oil or steam, is used when the distributor alternates between emulsion and hot bitumen work.
Transfer and dosing of bitumen emulsion
- Unloading of road tankers into storage tanks and loading of distributors with the NAV series, which primes on its own even with a partly empty suction line.
- Recirculation of storage tanks in emulsion plants, where a steady flow avoids separation during long standstills.
- Feeding of cold-mix and slurry-seal plants, where the pump delivers a constant flow regardless of changes in back pressure.
- Dosing of emulsion, emulsifiers and acids in the production line with the ZV series and an inverter, with volumetric efficiency close to 100%.
- Handling of fuel oils and fluxing agents in the same plant with the same pump families.
Stainless steel executions are available for acid emulsions and aggressive additives; ask us when you send your enquiry.
What we need to size your emulsion pump
Tell us the type of emulsion (cationic or anionic, slow or rapid setting, modified or not), the working temperature, the flow you need in l/min, the back pressure at the spray bar or in the transfer line, the installation (on the tank of a distributor, on a skid, in a plant) and the type of drive you prefer: electric motor, hydraulic motor or power take-off. For an emulsion sprayer pump, also give us the tank capacity and the number of nozzles on the bar.
Send these details on WhatsApp or use the quote form: our Bologna factory, building self-priming external gear pumps since 1955, answers with a technical proposal. For thicker products see our viscous fluid pumps.
Frequently asked questions
Can a gear pump break the bitumen emulsion?
An external gear pump moves the product with a regular flow and very low pulsation, so it treats the emulsion gently. Problems arise with high shear or strong turbulence, which our bitumen emulsion pumps are designed to avoid.
Does a bitumen emulsion pump need a heating jacket?
Usually not: emulsion is handled at much lower temperatures than hot bitumen. The SB series has an integral heating circuit for distributors that alternate between emulsion and bitumen; NAV and ZV are supplied without jacket.
Which pump do I need for an emulsion sprayer?
The SB series, which flanges directly onto the tank and performs loading, recirculation, spraying and transfer with two built-in valves. Choose the model by the flow required at the spray bar, from 57 to 1,093 l/min.
Can I dose emulsion with the same pump?
Yes. The ZV series doses small flows by varying motor speed with an inverter, with volumetric efficiency close to 100%. It is used for emulsifiers, additives and laboratory or pilot plant lines.