1. The challenge of asphalt pumping
Asphalt is not an ordinary fluid. It combines three characteristics that rule out most pump technologies: extreme viscosity, high temperature and solidification. A fluid that is liquid at 180°C and solid at 60°C requires a pump that maintains continuous heating and operates with internal clearances designed for high viscosity.
Centrifugal pumps do not work for asphalt. Efficiency drops sharply above 500 SSU. The gear pump is the only viable technology because volumetric efficiency improves with increasing viscosity — the opposite of centrifugal pumps.
2. The FBE-CA variant: integrated heating jacket
The CA (heating jacket) variant of the FBE series has a casing with an integrated jacket that circulates heating fluid around the pump body. This keeps the asphalt at pumping temperature even during extended shutdowns, preventing the product from solidifying inside the pump.
- Steam heating: maximum 185°C and/or 10 bar (per FBEI manual)
- Thermal fluid heating: maximum 232°C and/or 10 bar (per FBEI manual)
- Maximum product temperature: up to 350°C with proper mechanical seal
- Typical application: CAP 30/45, CAP 50/70 asphalt, asphalt emulsion, polymer-modified asphalt (PMA), petroleum residue
3. Selection by viscosity: how to size for asphalt
Asphalt viscosity depends directly on temperature. At pumping temperature (typically 150°C to 200°C), viscosity falls in the 2,500 to 10,000 SSU range. FBE manual Table 2 defines the speed and drive:
| Asphalt viscosity (SSU) | Speed (rpm) | Drive |
|---|---|---|
| 2,500 to 7,500 (hot CAP, ~180°C) | 850 | Direct |
| 7,500 to 10,000 (warm CAP, ~150°C) | 700 to 500 | Pulley or gearbox |
| 10,000 to 50,000 (cold CAP or PMA) | 500 to 300 | Pulley or gearbox |
4. Construction materials for asphalt
Material choice depends on the maximum continuous operating temperature. The FBE manual offers two main options for asphalt:
- Cast iron ASTM A48 CL30: standard for asphalt up to 250°C. Lower cost, good mechanical strength, most used material in Brazilian asphalt plants
- Carbon steel ASTM A216 WCB: for continuous operation above 250°C or for polymer-modified asphalt requiring higher thermal resistance
- Mechanical seal: type 21 with special faces for high temperature. For operation above 300°C, consult FB Bombas engineering for seal arrangement selection
5. Typical applications in the asphalt sector
The FBE-CA pump is used across the entire asphalt chain — from refinery to paving site:
- Asphalt plants: CAP transfer from storage tanks to the mixing plant
- Fuel distributors: loading and unloading of tank trucks
- Port terminals: transfer from ships to coastal tanks
- Asphalt emulsion production: precise CAP dosing in the emulsification process
- Polymer-modified asphalt (PMA/SBS): transfer of product with higher thermal demands
- Industrial waterproofing: asphalt membrane, primer and asphalt sealants
