Flux Pumps F 425 Ex S Kit: Drum Pump For Flammable Liquids and 99.9% Drum Emptying

• Pump type: Flux F 425 Ex S-41/34 with ceramic-oxide mechanical seal and PTFE foot valve. ATEX Zone 0/1 approved. 

• Outer tube material: Stainless steel 316 L 

• Driveshaft: 6 mm diameter stainless steel 316 L for maximum vibration resistance 

• Inner tube: Stainless steel 316 L 

• Impeller: ETFE axial impeller 

• O-rings: FKM (FFKM o-rings available on request) 

• Immersion lengths: 1000 mm (200-220 l drum) or 1200 mm (1000 l IBC) 

• Outer tube diameter: 41 mm 

• Foot valve: Manually operated PTFE non-return valve 

• Motor type: F 460 Ex, brushed commutator motor, fixed speed. ATEX Zone 1/2 approved 

• Power supply: 230V 50Hz 

• Ingress protection: IP55 

• Power rating: 460W 

• Duty cycle: S1 continuous duty 

• Housing type: Double wall, externally cooled, double insulated 

• Housing material: Aluminium with corrosion resistant paint 

• Cable length: 5 m  

• Plug type: UK 3-pin plug adaptor supplied 

• Alternative 110V motors and compressed air motors available on request. 

• Hose: Universal chemical hose, DN21, 2 m, with stainless steel swaged fittings 

• Hand nozzle: Stainless steel Ex hand nozzle with PTFE/ FEP seals 

• Compression gland: Conductive PP, G 2″ male thread 

• Also includes: Flux- Clip and earth ground wire, 2 m length 

• Max flow rate: Approx. 40 LPM¹ 

• Max delivery head: 8 mwc 

• Maximum liquid temperature: 100 degrees C (max 40 degrees C in ATEX Zoned areas) 

• Max density: Approx. 1.5 kg/L 

• Max viscosity: Approx. 600 mPas 

• Compliance: Suitable for use in hazardous areas (ATEX certified) 

* measured using water at 20°C with hose and hand nozzle connected. 

Carefully considered design features make the Flux F 425 Ex S the preferred pump for handling hazardous media in industrial environments. 

ATEX-certified for hazardous area use
ATEX-certified for Zone 0, 1 and 2 as appropriate, the F 425 Ex S is a safe electric pump for transferring flammable liquids. Conductive hoses and an integrated earth cable eliminate risk of static electricity build-up, thereby preventing accidental electrostatic discharge (ESD)—a cause of flash fire or explosion. 

99.9% drum emptying with foot valve
The integrated PTFE foot valve enables near-total container emptying, subsequently leaving less than 0.05 L in a 200 L drum. The backflow valve effectively reduces waste and additionally, the risk of hazardous vapour exposure. Minimising wetted surfaces within the pump reduces evaporation rate (according to Raoult’s Law), thereby limiting VOC release and potential exposure of the operator to dangerous media. 

1. Mechanical seal for aggressive or abrasive media
   A robust mechanical seal enables safe handling of pure, crystallising, or abrasive media, with FKM o-rings offering broad chemical compatibility. Unlike open shaft or seal-less pump designs, the mechanical seal stops volatile fluid creep and vapour loss, whilst eliminating the risk of solid particles causing premature bearing wear. The mechanical seal also prevents molecular leakage of low surface tension liquids. 

Corrosion-Resistant Materials for Chemical Durability 

With 316 L stainless steel tubes, ETFE impellers, PTFE gasket and optional FFKM o-ring upgrade, this pump resists corrosion from aggressive solvents, hydrocarbons and also polar liquids. Fluoropolymers (such as ETFE and PTFE) have low surface energy and chemical inertness, therefore preventing molecular interaction and breakdown in reactive media. 

High strength, long-life stainless steel driveshaft
The class-leading 6 mm diameter stainless steel driveshaft delivers superior durability. It is supported by up to six brass shaft bearings for wear resistance. Furthermore, the high strength shaft resists vibration and lateral deflection, ensuring smooth, quiet operation and long mechanical seal life. In addition, distribution of radial load through multiple bearings reduces friction and heat (per the Tribology Principle), thereby extending service life. 

Ready-to-use Ex pump kit
Lastly, supplied fully assembled, the F 425 Ex S kit includes all the components required for safe and efficient pumping. Available in 1000 mm and 1200 mm immersion lengths, the F 425 Ex S handles a wide range of fuels, alcohols, solvents, acids and additionally, urea derivatives, from 200 L drums or IBCs. The modular design with quick disconnect motor, plus chemically resistant materials, enable efficient fluid handling in diverse environments while meeting important safety standards. 

Please note, this drum pump for flammable liquids kit is not suitable for extended dry running (see our FP 424 pump kits) 

• Safe dispensing of flammable or volatile ingredients in cosmetics and fragrance production 

• Transfer of solvents and petroleum products across petrochemical production and storage facilities 

• Handling solvents and degreasing agents in manufacturing and engineering facilities 

• Filling, decanting, or refilling 200 L drums and IBCs for processing and transport. 

• Pumping in ATEX zoned areas, or environments containing flammable vapours where explosion protection is essential. 

This flammable drum pump kit is suitable for the following liquids: 

• Fuel additives, diesel and petrol  

• Ethanol, MEK, xylene, toluene, acetone and methanol  

• Propanol, butanol, formic acid (up to 85%), urea solutions and ethyl glycol 

• White spirit, hydraulic oil, engine oil, mineral oils and isobutanol  

Always verify chemical compatibility and ATEX certification requirements before use. For additional technical support, contact Flux Pumps UK. 

• ATEX-approved for handling low flash-point flammable media 

• Stainless steel 316 L and PTFE materials for chemical resistance 

• Low-maintenance, long-life design 

• Pulsation-free, controlled fluid transfer 

• Minimal liquid waste or drain back, with consequent reduction in disposal costs and improved operator safety 

• Compatible with both IBCs and drums 

• Serviceable design with all parts available to buy as spares 

• Transfer against closed valve (e.g. hand nozzle) possible 

View our full range of pre-assembled pump kits here.

Finally, find out more about our drum pump for flammable liquids options here.