Flux F 310 Polypropylene JuniorFlux 25L Drum Pump with Mechanical Seal

• Pump type: F 310 PP centrifugal drum pump with ceramic-oxide mechanical seal  

• Outer tube material: Polypropylene (PP) 

• Driveshaft: Hastelloy C 

• Inner tube: Reinforced polypropylene (fluid excluded from shaft housing) 

• Impeller: ETFE axial (chemical resistant) 

• O-rings: FKM 

• Immersion lengths: 500 mm and 700 mm (for small containers and hobbocks), 1000 mm (for 200 l drums)  

• Outer tube diameters: 25 mm and 32 mm 

• Outlet connection: G 1 A 

• Motor type: FEM 3070 brushed commutator motor, with two-stage speed control 

• Power supply: 230 V or 110 V (50–60 Hz) 

• Ingress protection: IP 24 

• Power rating: 230 W 

• Duty cycle: S1 continuous duty 

• Housing type: Single-walled, internally ventilated, double insulated (Class II) 

• Housing material: Polyamide 

• Weight: 1.5 kg 

• Max ambient temperature: -20 to + 40 degrees C 

• Cable length: 5 m  

• Plug type: UK 3-pin plug adaptor included with 230 V motor 

• Overload protection: Integrated cut-out 

• Certifications: UKCA, CE, VDE-GS 

Total weight (pump + motor): 1.8 – 2.1 kg 

Please note a hose connection is not included and must be purchased separately.  

• Max flow rate: Approx. 27 L/min1 (25 mm version) and 48 L/min1 (32 mm version) 

• Max discharge pressure: Approx. 5.0 mwc (25 mm) and 6.9 mwc (32 mm) 

• Maximum liquid temperature: 45 degrees C 

• Max density:  Approx. 1.3 g/cm³ (under continuous use) 

• Max viscosity: Approx. 250 mPas (under continuous use) 

• Dry run limitations: Not suitable for dry running (see alternative F 314 model) 

*Measured with water at 20 degrees C in open flow condition 

• Acid and alkali dosing in laboratory, metal recovery & plating, or water treatment applications (e.g., dilute sulphuric acid, sodium hydroxide, dilute nitric acid, hydrochloric acid) 

• Transfer of crystallising media, or media with suspended solids, such as phosphoric acid, urea solution, wastewater, waste coolant with cutting swarf. 

• Dispensing of cleaning agents, sanitisers or detergent concentrates with foaming or abrasive properties 

• Handling aqueous salt solutions in chemical preparation or buffer storage systems 

• Filling smaller vessels or containers with disinfectants or degreasers 

• Liquid fertiliser applications in production areas and agricultural settings 

Please see our comprehensive list of media examples for our 25l drum pump, based on pump material, here.

The F 310 pump offers a strategic advantage in any operation where fluid purity, equipment longevity, and cross-contamination control are critical. In contrast to low cost, disposable drum pumps, the F 310 incorporates a precision ceramic-oxide mechanical seal that forms a physical barrier between the pumped liquid and the motor shaft. This not only prevents ingress of fluid or solid particles into the shaft housing, but also reduces total wetted surface area, thereby reducing the risk of cross-contamination. 

The use of Hastelloy C for the driveshaft is particularly relevant when handling halogenated acids, or oxidising liquids. Hastelloy is exceptionally resistant to pitting, corrosion and stress cracking in chloride-rich environments. Combined with a tough ETFE impeller and FKM o-rings, F 310 is consequently designed to meet the challenges of corrosive chemical transfer. 

Moreover, the fixed FEM 3070 commutator motor is S1-rated for continuous operation, eliminating the risk of motor shut-down due to thermal overload. The selectable high / low-speed function allows the operator to vary flow rate, particularly useful when dispensing smaller amounts, or when pumping shear-sensitive fluids. 

Absolutely. The Flux F 310 PP 25L drum pump, particularly when specified with the smaller 25 mm pump tube, is ideal for use in narrow-necked and small volume containers, such as 25-litre carboys, hobbocks and reagent tanks. Furthermore, with its narrow profile and short, 500 or 700 mm long pump tubes, this pump facilitates easy insertion into restricted openings. 

The combination of high / low-speed control, ergonomic handle and lightweight construction provides precise, safe dispensing, even when using the pump with one hand. The mechanically sealed design reduces wetted area, thereby removing nearly all the liquid from the container and reducing drain back. This is particularly advantageous for high-value chemicals, or when residual waste is undesirable – for cost or safety reasons, or for inventory tracking. 

In addition, the pump provides excellent process control  for applications involving batch filling or sample withdrawal. Finally, you can add the optional FMT120 flow meter for monitoring volumetric dispensing. 

The distinction between sealed and seal-less models reflects a fundamental trade-off between ease of maintenance and fluid compatibility. 

• Firstly, the JuniorFlux F 310 with mechanical seal is engineered for fluids that are abrasive, crystallising, or contain suspended solids. Furthermore, the mechanical seal isolates the fluid from the pump’s drive mechanism, preventing wear to internal components and preserving shaft alignment over extended operating cycles. In addition, the pump has the lowest possible wetted surface area, making it a better choice when one pump is used with several different fluids. This design minimises the risk of residual fluid cross- contamination. Additionally, we find that mechanically sealed pumps handle high temperature liquids more reliably, as a result of improved dimensional stability. However, these pumps tend to be less well suited to pumping non-lubricating fluids. 

• In contrast, seal-less JuniorFlux F 314 models use an open inner tube configuration with no barrier between the shaft, bearings and fluid. While this reduces weight, complexity and preventative maintenance requirements, this design is less suitable for fluids containing solids in suspension, or liquids that leave crystalline deposits. Therefore, these pumps are the best choice for pure, clean fluids. Additionally, ss liquid enters the inner tube, wetted surface area is greater, making this design less suitable if cross-contamination is a concern. 

One final consideration – note that mechanically sealed pumps can only tolerate dry running for short periods as the mechanical seal may overheat, thereby leading to premature failure. Seal-less pumps can be run dry safely for longer periods, however, extended dry running can still cause bearing failure. 

The F 310 25l drum pump is a centrifugal axial rotor design, where an impeller rotating at high speed (typically 8 – 10,000 RPM) drives the media vertically up through the pump tube. The impeller is mounted as close to the pump inlet as possible, ensuring that almost all the liquid is removed from the container.  

At the heart of the pump lies the mechanical seal assembly, which is located between the impeller and the inner pump tube. This assembly comprises a fixed ceramic face, rotating ceramic face, spring assembly and an elastomeric FKM o-ring. Consequently, the rotating face turns at high speed with the impeller and the spring maintains a consistent seal between the two ceramic faces, stopping liquid from entering the inner tube. 

When the motor is engaged, the impeller induces axial flow, moving the liquid from the bottom of the container up through the pump body and out via the threaded side outlet port. Long-life, low friction bearings support of the driveshaft, including a heavily reinforced lower bearing, designed to eliminate vibration.  Because only a short length of the driveshaft is exposed to the liquid (between the impeller and mechanical seal) the rest of the shaft and the bearings are completely protected from chemical attack, crystallisation and wear associated with ingress of solid particles.  

The ETFE impeller maintains dimensional stability and hydrodynamic efficiency, while providing exceptional resistance to chemicals, including acidic and alkaline solutions. The two-speed drive motor provides additional flexibility, for use across a range of container sizes and flow rate requirements. The operator can toggle between high-speed (for fast emptying) and low-speed (for controlled filling).  

• Engineered mechanical seal isolates abrasive fluid from the motor and bearings, thereby increasing lifespan and reliability 

• Chemical-resistant wetted parts (Polypropylene, Hastelloy C, PTFE, ETFE, ceramic-oxide) are compatible with acids, alkalis and corrosive reagents 

• Various pump tube lengths and diameters available, depending on container size and application 

• Compact 25 mm diameter pump suitable for 25-litre drums and narrow-necked containers 

• Selectable motor speeds allow for fast bulk transfer and dosing control 

• Continuous duty S1-marked motor, suitable for continuous operation. Also includes standard overload protection. 

• Lightweight, portable, ergonomic design supports one-handed use in restricted access areas 

• Ideal for solids-entrained, or crystallising media where seal-less pumps would fail rapidly 

• Manufactured in Germany, to meet the highest industrial quality standards 

• 25 l drum pump available as a complete kit including hand nozzle and discharge hose  

Learn more about our Flux pump kits 

Explore our JuniorFlux drum and barrel pump range