1. The two main families: water-based and solvent-based
Coating technology is organized into two main families: paints and varnishes based on organic solvents (for example toluene, xylene, ethyl acetate, methyl ethyl ketone and aliphatic hydrocarbons) and water-based paints, where the vehicle is a resin dispersion in an aqueous medium stabilized by surfactants.
Latex and acrylic architectural paints are generally water-based; many industrial, marine, automotive and wood coatings still use solvent because of adhesion, cure and resistance requirements.
For pump specification, the difference is large: water-based lines usually operate without a relevant flammable atmosphere, while solvent lines have classified areas defined by the project, with Ex motors and instruments, equipotential grounding and ventilation. Area classification — not the product name — decides the motor; the same plant may have classified and non-classified areas, physically separated.
2. Base resins: alkyd, epoxy, polyester, polyurethane, acrylic
Resins are the structural ingredients of paints and varnishes: the component that forms the film after drying or curing.
The most common families are: (1) alkyds, made from vegetable oils or fatty acids, polyols and polycarboxylic acids, used in enamels and wood paints; (2) epoxies, obtained by reacting bisphenol A with epichlorohydrin, used in industrial anticorrosive painting; (3) polyesters, used in powder coatings and industrial coatings; (4) polyurethanes, used in varnishes and automotive painting; and (5) acrylics and vinyls, frequent in water-based architectural paints.
Each family is produced in synthesis reactors, with intermediates whose viscosity increases along the reaction.
For the pump, this means selecting for the viscosity range of the whole cycle, from initial charge to final product, and for the process temperature.
The FBE has a recommended speed per viscosity band from 30 to 100,000 SSU (2026 catalog, p.5); the FBEI publishes an independent maximum of 140,000 cP and a series temperature up to 340 °C, with the jacket limited to steam up to 185 °C and thermal fluid up to 232 °C, both at 10 bar (MAN001-10). When the maximum cycle viscosity or the temperature exceed what a documented configuration covers, engineering assesses engineered-to-order alternatives.
Note
Resin reactor heating often uses thermal oil. The FBOT is the FB Bombas series for that circulation (series limit: 350 °C), selected from the thermal fluid data and the operating point; the thermal oil guide details the criteria.
3. Pigment dispersion: grinding and abrasive recirculation
Pigment dispersion is one of the most demanding stages for the pump: pigments and mineral fillers, such as titanium dioxide, iron oxides and calcium carbonate, are dispersed in the vehicle down to the specified fineness, measured for example on the Hegman scale.
In the bead-mill process, the mixture recirculates between pump, mill and tank; while dispersion is incomplete, hard particles accelerate wear of impellers, gears, bushings and seals.
The FBE and FBCN manuals advise consulting FB for fluids with suspended solids. On the FBCN, seal chamber execution S3 provides flushing with clean liquid from an external source for fluids with abrasive particles or a tendency to crystallize (up to 105 °C); on the FBE, gear and bushing materials and reduced speed enter the assessment.
State the type and content of solids, particle size and recirculation duty. Wear in these services must enter the maintenance plan, with defined spare parts; special coatings outside the standard documentation are assessed as engineered-to-order. FB does not publish component life for abrasive service.
4. Solvent pumps and solvent-based paints: classified areas, sealing and NPSH
Solvent paint lines have classified areas defined by the project, in zones: Zone 1 (explosive atmosphere likely in normal operation) or Zone 2 (not likely in normal operation and, if it occurs, of short duration).
Electrical design follows ABNT NBR IEC 60079-10-1 for classification and ABNT NBR IEC 60079-14 for design, selection and erection. In Brazil, NR-10 (item 10.9.2) requires conformity assessment of equipment for potentially explosive atmospheres, and electrical equipment covered by the regulation requires compulsory certification under Inmetro Ordinance No. 115/2022; the certification required in the country is the Inmetro one.
On the pump, this translates into an Ex motor suited to the zone, gas group and temperature class; a coupling guard in non-sparking material, an option in the FBE and FBCN manuals; equipotential grounding between pump, motor, baseplate and piping; and instrumentation suited to the zone. FB Bombas quotes the assembly with a motor certified by the motor manufacturer, and FBE, FBEI and FBCN can be specified in this configuration according to product viscosity.
In solvent pumps, sealing comes first. The FBE 2026 catalog includes solvents in the Chemical card (p.3) and offers packing, mechanical seal or lip seal, with a relief valve in brass or AISI 304 stainless steel; the FBEI 2026 catalog provides packing and single, double or cartridge mechanical seals among its sealing options (p.3).
On the FBCN, used for low-viscosity products, the packed arrangement the manual indicates for toxic, aggressive or malodorous fluids is S1, sealed with clean liquid from an external source (MTEC-03/00, item 10); with a mechanical seal, the arrangement follows the application.
At suction, the solvent’s vapour pressure at the real temperature enters the available NPSH. At 20 °C, from NIST data, water has 2.34 kPa, toluene 2.9 kPa and acetone 24.6 kPa — about ten times water. Use the value for the solvent and line temperature, from the safety data sheet or a database, and prefer a short, flooded suction when the product is volatile.
5. Cleaning and color change: the operational bottleneck
Paint plants produce many colors and formulations on shared equipment; each change requires cleaning of the pump, piping, mixer and filler with a compatible solvent or water with detergent.
For the pump, cleaning depends on draining the product, circulating the cleaning agent and, when needed, dismantling for manual cleaning — for example, when changing from strong to light colors.
In the specification, state the change frequency, cleaning agent and temperature, so that materials and elastomers are compatible. The FBEI has back-pull-out construction and reversible rotation (2026 catalog), and the FBE catalog lists the series replacement components; drain points, sealing type and cleaning access are defined in the proposal. FB does not publish color-change times.
Specify the casing, internal parts and sealing
For paints and resins, start with product composition and define the material of each pump part. FBE has separate options for the casing and covers, shafts, gears and bushings. For FBEI, the general casing, gear and bushing specifications and the standard series casing and support options have different scopes. The proposal should identify the selected construction; the casing material does not define the internal parts.
FBEI sealing options include packing and single, double or cartridge mechanical seals. Provide the product, temperature, pigments, fillers, cleaning agents and containment requirements to assess the configuration. If the enquiry specifies API 682, confirm the seal execution: its mention among sealing options does not certify the complete pump.