Manufacturer of Gear Pump

A gear pump is a positive displacement pump that uses the meshing of two or more gears to transport fluids from suction to discharge. Each rotation delivers a fixed volume of liquid regardless of system pressure — a principle that ensures constant, predictable flow. The fluid fills the spaces between the teeth and the inner casing wall and is carried in pockets around each gear, with no metal-to-metal contact between them. It is the most widely used technology in industry for pumping viscous fluids such as oils, resins, asphalt and chemicals. FB Bombas has manufactured gear pumps in Cabreúva, Brazil, since 1944: the FBE series (external gear) covers DN 1/8" to 6" with flows from 0.5 to 6,500 L/min, pressures up to 22 kgf/cm² and temperatures up to 350°C, in compliance with API 676.

In an external gear pump, two identical gears mounted side by side rotate in opposite directions, carrying the fluid between the teeth and the casing wall. In an internal gear pump, a rotor spins inside a ring, separated by a fixed crescent that seals suction from discharge. Internal gear offers quieter operation, lower pulsation (typically below 5% of the mean value) and lower shear, being indicated for sustained viscosities above 1,000-2,000 cSt, precision dosing and sensitive polymers. External gear supports higher pressures, is more robust, more versatile and tolerates difficult start-ups. At FB Bombas, the FBE series (external) covers DN 1/8" to 6" with pressures up to 22 kgf/cm²; the FBEI series (internal) offers 10 models from 1" to 4", with an optional integrated relief valve and typical volumetric efficiency of 90-97%.

Gear pumps are ideal for viscous fluids: lubricating and hydraulic oils, resins, adhesives, paints, varnishes, chocolate, molasses, bitumen, asphalt, polymers and chemicals. The viscosity range served goes from 1 cP to over 1,000,000 cP — on the FBE series, the operating range documented in the technical manual is 30 to 100,000 SSU, with rotation adjusted to viscosity: 1,750 rpm for thin fluids down to 150 rpm for the heaviest. Material selection follows the fluid: ASTM A48 cast iron for oils and general applications, 316 stainless steel (ASTM A743 CF8M) for corrosive and food-grade fluids, carbon steel for petrochemical service. Typical sectors include chemical, petrochemical, pulp and paper, steel, mining, food, textile, pharmaceutical, sanitation and asphalt. For shear-sensitive fluids or extreme viscosity, the FBEI internal gear series is the indicated option.

Yes. Gear pumps are self-priming: the meshing of the gears creates sufficient partial vacuum on the suction side to draw fluid without the need for a foot valve or auxiliary priming device. In practice, this allows the pump to start while drawing liquid from reservoirs positioned below the pump line, simplifying installation in tank transfer and process unloading. Both FB Bombas series follow this principle: the FBE (external gear) is self-priming across the entire DN 1/8" to 6" range, and the FBEI (internal gear) technical manual documents self-priming and flow reversibility, with a recommended 40-80 mesh suction filter to protect the rotating assembly. Priming capacity depends on hydraulic sealing through the close-fit clearance between gears and casing — which is why excessive internal wear reduces suction performance.

FB Bombas gear pumps operate with flows from 5 L/min (FBE 1/8") up to 6,500 L/min, or 390 m³/h, on the FBE 6" DA model at 1,750 rpm — with pressures up to 22 kgf/cm² and head up to 220 m across the entire FBE series (external gear), spread over 12 standardized sizes from DN 1/8" to 6". The FBEI series (internal) handles flows up to 600 m³/h with pressure up to 16 bar. Maximum operating temperature reaches 350°C, served by the CA version with heating chamber, used for asphalt and thermal oil. Working speed is defined by fluid viscosity per Table 2 of the technical manual: from 1,750 rpm for 30-250 SSU fluids down to 150 rpm for fluids up to 100,000 SSU. For higher flows, parallel pumps are sized by application engineering.

Choose a gear pump when the fluid is viscous (above 100 cP), when you need constant flow independent of pressure, when the fluid is shear-sensitive, or when precise dosing is required. The reason lies in the working principle: a centrifugal pump is a dynamic pump whose flow varies with system resistance and whose efficiency drops drastically above 100 cP, with falling flow and rising power consumption. A gear pump, being positive displacement, delivers a fixed volume per rotation under any pressure condition within the equipment limit. As a practical reference, above roughly 200 SSU the gear pump already outperforms the centrifugal in efficiency. For water and low-viscosity fluids at high flows, the centrifugal is more efficient and economical — in that case, FB Bombas recommends the FBCN series (standardized centrifugal) instead of the FBE.

In many cases, yes. The FBE and FBEI series are candidates to replace gear pumps from manufacturers such as Edral, Hidex, RZR, Viking, Netzsch and Maag, with custom sizing and direct manufacturer technical support. Reusing the existing base and piping is confirmed case by case, from the dimensional drawing, connections, speed and torque. The process is simple: send the nameplate of the current pump, the base dimensions and the process data (fluid, flow, pressure, temperature and viscosity) to application engineering, which returns the equivalent specification within 48-72 business hours. Typical lead time is 30 to 60 calendar days, versus 4-8 months for a direct import, a critical difference in unplanned shutdowns. Since manufacturing and the spare-parts stock are located in Cabreúva, Brazil, spare availability is permanent, with no import dependency throughout the entire service life of the equipment.

A gear pump operates by positive displacement: as the gears rotate, their teeth create chambers on the suction side that trap fluid between tooth and casing, transport it around the outer chamber, and expel it on the discharge side. Each rotation delivers a fixed volume regardless of pressure. The principle is mechanical (not kinetic), which is why flow remains stable even at high viscosities.

A gear pump is mechanically simpler than diaphragm, screw, or lobe pumps — only two main moving parts (the gears), no valves, no membranes, no exposed elastomers. Result: lower cost, less maintenance, higher MTBF. Typical flow ranges from 0.5 to 6,500 L/min in a single FBE pump, a range that diaphragm pumps would require multiple parallel units to match.

Yes, and it is critical. Gears operate with micron-level clearances — solid particles above 100 μm cause accelerated wear on teeth and casing. FB Bombas recommendation: Y-strainer 100-mesh (150 μm) on the suction line for clean fluids, or basket strainer 200-mesh (75 μm) for used oils, biodiesel, and fluids with sediments. Filtration area should be at least 3× the pipe area to avoid excessive pressure drop.

Yes — one of the inherent advantages. Reversing the motor direction makes the pump suction shift to the opposite port, useful for tank refill/drain operations without reconfiguring piping. FBEI (internal gear) is fully reversible by construction. FBE (external) is also reversible, but for continuous bidirectional service we recommend a dual-face relief valve. In both cases, a check valve on the line protects against unwanted reverse flow when the pump is idle.

Linear: flow is directly proportional to rotation. Doubling rpm doubles flow. This enables precise control via VFD (variable frequency drive), replacing control valves and eliminating throttling losses. For extremely viscous fluids (above 10,000 cP), reducing rpm to 600-1,150 rpm is standard practice — it protects gear teeth from induced cavitation and extends service life. FBE typically operates between 1,150 and 1,750 rpm.

A gear pump consists of: gear pair (pinion and gear on external; rotor and internal ring on the FBEI), casing with micron clearances providing the hydraulic seal, shafts supported by bushings lubricated by the fluid itself, shaft sealing (mechanical seal or packing), relief valve against overpressure (body-integrated option on the FBEI), heating chamber on the CA version for fluids that solidify when cold, and the drive — direct electric motor, gearbox or pulleys. The exploded view with the complete parts list of each model is in each series technical manual, available for download in the technical manuals section.

The standard drive is an electric motor mounted with the pump on a single steel baseplate, with flexible coupling and guard. Since working speed is defined by fluid viscosity — from 1,750 rpm on thin fluids (30-250 SSU) down to 150 rpm on fluids up to 100,000 SSU — heavy fluids require a speed reducer or belt-and-pulley transmission between motor and pump. The complete pump-motor set (pump + motor + gearbox + baseplate + coupling) is supplied by FB Bombas already assembled, aligned and bench-tested, sized by application engineering according to fluid and operating conditions.

The technical manuals for the FBE (external gear) and FBEI (internal gear) series are available for free download in the site’s technical manuals section, in PDF, with performance curves, flow-per-speed tables, dimensions, materials of construction, exploded view and installation, operation and maintenance instructions. The complete specifications of each model — from FBE 1/8" to FBE 6" DA and the 10 FBEI models — are also on the series pages, with a model selector by flow and pressure. For assisted selection, application engineering replies with the proper specification within 48-72 business hours.

The FBE 3" is one of the most used sizes in the series for transferring oils, asphalt and viscous chemicals at medium flow. Choosing among the variants — standard, double (DA) or with heating chamber (CA) — depends on four data points: desired flow, differential pressure, viscosity at pumping temperature and whether the fluid solidifies when cold. The same nominal diameter delivers different flows depending on the applied speed, defined by the manual’s viscosity × rpm table. The full FBE 3" specifications — curves, dimensions, materials and weights — are on the model’s specification page in the FBE series section; to confirm the correct variant, send your process data to application engineering.

It depends on the fluid. For clean viscous fluids — oils, asphalt, resins, polymers and chemicals — the gear pump wins: all-metal construction operates up to 350°C, precise dosing with flow proportional to rotation and only two main moving parts. For abrasive fluids with suspended solids — sludges, slurries and pulps — the progressive cavity pump is the right choice: its elastomer stator tolerates particles that would wear out the micron-level clearances of a gear pump, but that same elastomer limits operating temperature and is a periodic wear part. FB Bombas manufactures gear pumps (FBE external and FBEI internal, per API 676) — it does not manufacture progressive cavity pumps. If your fluid is viscous and clean, or hot beyond the elastomer limit, the gear pump is technically superior. The series manual itself advises: "For fluid with suspended solids, FB must be consulted" (FBE Technical Manual, MTEC-01/01, §2.3, translated from the Portuguese original).