1. Formulation and rheology: data that change pump selection
An important starting point is not to treat all products in the sector as similar liquids. Detergents, shampoos, creams, lotions and gels cover a wide rheological spectrum, and many are non-Newtonian: the viscosity measured at rest may differ from the viscosity inside the pump.
Some formulations tolerate the shear of a centrifugal pump; emulsions and structured gels may lose consistency or separate phases under intense shear. This sensitivity is a property of the formulation and must be stated by the formulator.
The first question of any project is therefore: what is the product viscosity curve at operating temperature and what is its sensitivity to shear.
| Family | Examples | Data to confirm | FB series to evaluate |
|---|---|---|---|
| Low-viscosity liquids | Diluted detergent, process water, toners | Viscosity, chemical compatibility, flammability (alcohol-based products) | FBCN; FBE when the installation calls for positive displacement |
| Medium-viscosity liquids | Shampoo, liquid conditioner, liquid soap | Viscosity curve and shear sensitivity | FBCN or FBE after assessing rheology and duty point |
| Viscous products and sensitive emulsions | Creams, lotions, gels, pastes | Viscosity at the process shear rate; suspended solids | FBE or FBEI at low speed |
2. Shampoo and conditioner: selection for medium-viscosity products
Shampoo is usually an aqueous solution or dispersion of surfactants, such as sodium laureth sulfate and cocamidopropyl betaine, with conditioning agents, preservatives, fragrance and colorants. Viscosity is adjusted in the formulation and varies from product to product.
Foaming, aeration and shear sensitivity need assessment during recirculation and filling. Confirm these behaviors with the formulator and provide rheological data. The ANSI/HI 9.6.7 performance correction addresses Newtonian liquids; it must not be applied automatically to shampoos, gels or emulsions whose behavior depends on shear.
With the FBCN, selection considers the 1,750 and 3,500 rpm speeds in the manual (60 Hz), VFD control when needed, an A743 CF8M stainless casing and a stainless steel impeller among the documented options, and a mechanical seal defined by the application, with elastomers chosen for compatibility with surfactants, fragrances and cleaning agents. Conditioners with cationic agents follow the same reasoning; elastomer compatibility must be confirmed with the seal manufacturer.
3. Creams and lotions: gear pumps and controlled shear
Creams, lotions, moisturizers and similar products are emulsions — oil-in-water (O/W) or water-in-oil (W/O) — stabilized by emulsifiers. Their structure can be affected by excessive shear, temperature and air entrainment.
High-speed centrifugal pumps impose high shear on the product; sensitive emulsions are therefore usually transferred by positive displacement pumps at low speed — gear, lobe or screw, depending on viscosity, solids and cleaning requirements.
At FB Bombas, the FBE runs at a speed chosen by viscosity (2026 catalog, p.5), and the FBEI is driven through a gear reducer and runs at low speed, with constant flow, self-priming and reversible rotation (FBEI 2026 catalog). The choice between them depends on viscosity, flow, pressure and sealing and cleaning requirements; the emulsion sensitivity to shear must be validated by the product manufacturer.
According to the FBEI 2026 catalog (p.4), low speed through a gear reducer gives longer service life, low NPSH required, higher efficiency and lower noise.
When the product viscosity is given in centipoise (cP), it has to be converted, because the FBE 2026 catalog selects speed in SSU. The conversion is in the catalog itself (p.5): kinematic viscosity, in centistokes (cSt), is the viscosity in cP divided by the density in g/cm³, and above 300 SSU the approximation SSU = cSt × 4.635 applies. For a non-Newtonian product, convert the viscosity measured at the process shear rate.
Example with an illustrative value: a product of 10,000 cP with a density of 1.0 g/cm³ has 10,000 cSt, or about 46,000 SSU. In the catalog’s recommended-speed table (p.5), the 10,000 to 50,000 SSU band calls for 500 to 300 rpm, through a pulley or gear reducer, on sizes 1.1/2" to 6"; from 50,000 to 100,000 SSU, speed drops to 300 to 150 rpm, on 3" to 6" only.
Note
Products with solid particles — exfoliants and creams with micro-beads — require attention to wear of gears and bushings. The FBE manual advises consulting FB for fluids with suspended solids; in some cases another positive displacement technology is more suitable.
4. Powder soap and detergent: industrial scale and variable chemistry
Soap manufacturing produces powder soap, bar soap, liquid detergent and fabric softeners, with quite different processes.
Powder soap is produced by spray drying an alkaline slurry, followed by mixing with dry ingredients; bar soap, by saponification of oils and fats with caustic soda, followed by finishing and molding; liquid detergent, by blending surfactants in water with pH adjustment, colorants and fragrance.
Each stage has its own pumping points, with distinct requirements.
In saponification, the critical points are oil feed, caustic soda solution transfer, circulation of the viscous saponified mass and transfer to finishing. Caustic solutions and alkaline masses need materials and sealing chosen by concentration and temperature; the FBE lists soaps, detergents and bases among the applications in its 2026 catalog. In liquid detergent, the FBCN handles low-viscosity liquid transfer, and concentrated or thickened products may call for the FBE. Slurries for spray drying need assessment by solids concentration: consult FB.
On the FBE, the internal relief valve is a 2026 catalog accessory and comes in brass or AISI 304 stainless (p.3); include it in the chemical compatibility check, together with the casing. When the mass must be kept hot inside the pump, the heating chamber, another catalog accessory, is available from 1.1/2" to 6" (manual MTEC-01/01, Table 1).
5. Surfactants and intermediates: aggressive upstream chemistry
The upstream chain produces surfactants — LAS (linear alkylbenzene sulfonate), lauryl sulfate, lauryl ether sulfate, betaines and others — often in concentrated, acidic or alkaline form.
Pumps in this chain may operate with extreme pH, elevated temperature and products whose viscosity changes with concentration. Ask the surfactant supplier for the technical and safety data sheets, with viscosity, handling temperature and material compatibility.
The FBCN manual documents casings in cast iron, A216 WCB carbon steel and A743 CF8M stainless; special alloys outside this list are assessed as engineered-to-order solutions. For concentrated acidic products, such as the sulfonic acid that yields LAS, material compatibility at operating temperature decides feasibility — confirm with engineering before specifying.
For FBCN sealing, the packed arrangement the manual indicates for toxic, aggressive or malodorous fluids is S1, sealed with clean liquid from an external source, up to 105 °C (MTEC-03/00, item 10); with a mechanical seal, the arrangement follows the application. On the FBE, the 2026 catalog lists acids and bases in the Chemical card (p.3); confirm each product’s compatibility with engineering.
6. Good manufacturing practices: what falls to the pump
Manufacturers of personal hygiene products, cosmetics and perfumes follow the good manufacturing practices defined by ANVISA. Equipment qualification, cleaning validation and process water control are responsibilities of the cosmetics manufacturer, within its quality system.
For the pump, this translates into purchasing data: wetted-part materials, elastomers compatible with the product and cleaning agents, ease of disassembly and drainage, and equipment documentation. FBCN, FBE and FBEI are industrial pumps; when the process requires a specific hygienic design, state the requirement for assessment.
Documentation is defined in the proposal — for example, wetted-part material certificates and a test certificate with curve, when contracted. State in your enquiry which documents your plant qualification requires.
On the FBE, sealing is selected according to the pumped fluid (manual MTEC-01/01, p.1): the 2026 catalog offers packing, mechanical seal or lip seal (p.3), and the manual’s standard seal is type 21, in ceramic, graphite and Viton, with an AISI 304 stainless spring (item 2.5). State the product and the cleaning agents in your enquiry, so that this elastomer can be checked.
On the FBEI, the 2026 catalog provides packing and single, double or cartridge mechanical seals (p.4).