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Price range: £446.57 through £943.65 Excluding VAT
Class‑leading, heavy‑duty F 424 drum pumps dispense almost any liquid from 200‑litre drums, IBCs, tanks and process vessels.
Category | Details |
| Pump type | Flux F / FP 424, seal‑less, centrifugal drum transfer pumps |
| Ex‑classification | Ex II 1/2 G IIB T4 (stainless‑steel version only) |
| Outer tube material | Polypropylene (PP); PVDF; Stainless Steel 316 Ti |
| Driveshaft | Heavy‑duty Hastelloy C or Stainless Steel, 6 mm diameter for maximum vibration resistance |
| Inner tube | Polypropylene; PVDF; Stainless Steel 316 Ti |
| Impeller | ETFE axial impeller; optional semi‑axial impeller available |
| Bearing material | Flux PTFE spiral driveshaft bearing with oversize lower bearing housing |
| O‑rings | FKM; optional FFKM or FEP (vapour seal only) |
| Immersion lengths | 700 mm (small containers/hobbocks); 1000 mm (200 L drums); 1200 mm (1,000 L IBCs); custom lengths available |
| Outer tube diameter | 40–50 mm* (depending on model) |
| Outlet connection | G 1 1/4” A BSPP |
| Max flow rate | Approx. 240 L/min¹ |
| Max discharge pressure | Approx. 30 mwc¹ |
| Maximum liquid temperature | 50°C (PP); 80°C (PVDF); 100°C (Stainless steel); 60°C (HT version) |
| Max density | Approx. 1.9 g/cm³ |
| Max viscosity | Approx. 1,200 mPas |
| Dry run limitations | Suitable for limited dry‑running |
| Solids handling | Not recommended for large quantities of solids (use F 430 for solids) |
| Motor options | F 414; F 416 Ex; FEM 4070; F 457; F 458; F 460 Ex; FBM 4000 Ex; FBM 4100 |
| Notes | Measured with water at 20°C in open‑flow conditions. Performance depends on application, fluid properties and also pump configuration. Dependent on pump type, diameter and additionally motor. |
Please note: our drum transfer pumps do not include a hose connection; you need to purchase it separately.
*AdBlue® is a registered trademark of: Verband der Automobilindustrie e. V. (VDA)
Firstly, the two lateral slots near the inlet of the F 424 pump are known as pressure equalisation ports. As liquid enters both the inner and outer pump tubes, these ports allow pressure to stabilise between the two tubes. They are also necessary to facilitate drainage of the inner tube.
When the liquid level in the drum falls below these ports, a small amount of liquid can be seen flowing from the ports under pressure. The same can be seen when the pump is turned off, as residual liquid held in the pump tube during operation, drains out.
This behaviour is typical for centrifugal drum pumps of this type and is nothing to be concerned about. A residual quantity of liquid (approximately 10 mm depth) will always be left in the container. This is because the pump can no longer operate once air enters the pump inlet and the impeller is no longer submerged.
This is a known limitation of axial impeller drum pump designs, such F 424.
However, when the pump motor is switched off, residual liquid that is trapped in the pump tube (and to a possible extent, the discharge hose) will also drain back into the drum. This can comprise several litres of liquid, therefore creating the appearance that the pump has not emptied the drum.
The Flux F 424 is a centrifugal immersion type drum pump that uses the kinetic energy of a high-speed rotating impeller to generate fluid movement. Firstly, it relies on atmospheric pressure to push liquid to the impeller – the pump does not suck up liquid. The impeller spins within the lower pump housing, energising the liquid and driving it up through the pump tube, before expelling the liquid through the side discharge port.
What distinguishes the F 424 is its seal-less design. The pumped fluid is allowed to flow into the inner tube (housing the drive shaft and bearings), where it reaches the same level as the fluid in the drum. As liquid is dispensed, the level inside both the container and the pump naturally drop.
Importantly, this design eliminates the requirement for a mechanical shaft seal – a wear part that requires preventative replacement, to eliminate leakage risk. Once emptying is complete, the drive motor is shut down and any residual fluid drains fully through the pump inlet and pressure relief openings, thereby leaving minimal residue inside the pump.
The unique spiral guide bearing plays a crucial role in this process by centralising the shaft, reducing radial play and eliminating turbulent flow. This improves energy efficiency and protects both the bearings and the impeller from premature wear, even in continuous duty cycles.
Furthermore, the spiral design also promotes drainage, ensuring that liquid is not trapped inside the inner pump tube.
