Flender FLUDEX FAD 450 Hydrodynamic Fluid Coupling
The Flender FLUDEX FAD 450 is a benchmark hydrodynamic fluid coupling operating on the wear-free Föttinger principle, where input and output components transmit power via fluid kinetic movement without mechanical contact[cite: 21]. Featuring an integrated delay chamber (Type FAD)[cite: 21], the FLUDEX FAD 450 delivers soft, shock-free starting of heavy masses, protects motors from high starting current peaks, and provides automatic overload protection across heavy industrial drivetrains[cite: 21]. Available in 15 standard sizes (sizes 222 to 840) covering power transmission from 1.2 kW up to 2,500 kW[cite: 21], FLUDEX couplings offer flexible configurations with basic designs (FAO), delay chambers (FAD/FGD), extended delay chambers (FVO), integrated brake discs/drums (FADB/FNDB), and attached N-EUPEX or ARPEX flexible couplings[cite: 21]. They are extensively specified in overland belt conveyors, bucket elevators, ball mills, crushers, centrifuges, and industrial agitators[cite: 21].
Technical Specifications
| Model / Part Number | FLUDEX FAD 450 (Type FAD, Size 450 with Delay Chamber)[cite: 21] |
|---|---|
| Brand / Manufacturer | Flender GmbH[cite: 21] |
| Operating Principle | Hydrodynamic power transmission on the Föttinger principle (Wear-free)[cite: 21] |
| Power Transmission Range | 1.2 kW to 2,500 kW (Full Series Range Size 222 to 840)[cite: 21] |
| Attached Coupling Type | N-EUPEX Flexible Pin Coupling (Type FAD) or ARPEX All-Steel Disc (Type FND)[cite: 21] |
| Working Medium | Mineral Hydraulic Oil (HLP ISO VG 22 / VG 32) or Synthetic Fluids[cite: 21] |
| Thermal Overload Protection | Fusible Safety Plugs (110°C, 140°C, 160°C), EOT Thermal Switch, EOC Sensor[cite: 21] |
| ATEX Certification | Certified according to 2014/34/EU Directive for explosive atmospheres (Zone 1/21 & 2/22)[cite: 21] |
Documentation & Resources
Flender FLUDEX Series Modular Architecture Matrix
Full-range structural configuration guide for Flender FLUDEX hydrodynamic fluid couplings[cite: 21]. Review supported execution designs, delay chamber options, attached flexible couplings, and brake elements:
| Coupling Execution Series & Layout | Frame Sizes Covered | Power Transmission Capability (kW) | Standard Structural Features & Attachments |
|---|---|---|---|
| Type FAO (Basic Design without Delay Chamber)[cite: 21] | Sizes 222 to 840 (12 Sizes)[cite: 21] | 1.2 kW - 2,500 kW[cite: 21] | N-EUPEX (Attached Flexible Pin Coupling) |
| Type FAD (Standard Delay Chamber Design)[cite: 21] | Sizes 222 to 840 (12 Sizes)[cite: 21] | 1.2 kW - 2,500 kW[cite: 21] | Delay Chamber (Reduces Starting Torque) |
| Type FVO / FVD (Extended Delay Chamber)[cite: 21] | Sizes 370 to 655 (6 Sizes)[cite: 21] | 15 kW - 1,000 kW[cite: 21] | Extended Chamber (For Conveyor Belts) |
| Type FND / FNDB (ARPEX All-Steel Disc Output)[cite: 21] | Sizes 295 to 655 (7 Sizes)[cite: 21] | 10 kW - 1,200 kW[cite: 21] | ARPEX Disc Pack (Backlash-Free Rigid) |
| Type FADB / FADS (With Brake Disc or Drum)[cite: 21] | Sizes 295 to 755 (10 Sizes)[cite: 21] | 10 kW - 1,800 kW[cite: 21] | Brake Disc / Drum (Safety Stop Systems) |
Legacy Fluid Coupling Replacement & FLUDEX Upgrade Guide
Obsolete hydrodynamic fluid couplings or direct-on-line electrical motor starters on heavy conveyors can be upgraded to Flender FLUDEX fluid couplings[cite: 21]. Refer to the replacement mapping below for 1-to-1 retrofitting:
| Legacy Fluid Coupling / Starter Code | Drive System Type | Current FLUDEX Equivalent Model | FLUDEX Power Rating | Mechanical Fit & Retrofit Engineering Notes |
|---|---|---|---|---|
| Flender FAO 425 / FAD 425[cite: 21] | 1st Gen Fluid Coupling[cite: 21] | FLUDEX FAD 425 / FAD 450 FLUDEX Upgrade[cite: 21] | Up to 250 kW[cite: 21] | Direct 1-to-1 shaft diameter & N-EUPEX pin match[cite: 21]. |
| Flender FAD 450 / FAD 490[cite: 21] | 1st Gen Fluid Coupling[cite: 21] | FLUDEX FAD 450 / FAD 490 FLUDEX Upgrade[cite: 21] | Up to 400 kW[cite: 21] | Identical shaft centerline height & N-EUPEX buffers[cite: 21]. |
| Direct-On-Line Motor Starters[cite: 21] | Rigid Electrical Start[cite: 21] | FLUDEX FAD / FVO Series Soft Start[cite: 21] | Up to 2,500 kW[cite: 21] | Smooth hydrodynamic acceleration reduces electrical current spikes[cite: 21]. |
| Heavy Conveyor Belt Drives[cite: 21] | Standard Fluid Coupling[cite: 21] | FLUDEX FVO / FVD Extended Delay Conveyor Duty[cite: 21] | Up to 1,000 kW[cite: 21] | Extended delay chamber protects conveyor belts from tearing[cite: 21]. |
| High-Temperature Thermal Drives[cite: 21] | Basic Fusible Plug Unit[cite: 21] | FLUDEX + EOC / EOT Electronic Sensor Smart Monitor[cite: 21] | Full Range 222-840[cite: 21] | Non-contact EOC sensor detects slip and isolates motor before plug melts[cite: 21]. |
Expert Selection & Retrofit Engineering Notes
When retrofitting an existing drive featuring older FAD 370, FAD 425, FAD 450, or competitor fluid couplings[cite: 21], choosing original FLUDEX units ensures complete 1-to-1 mechanical interchangeability and reliable overload protection[cite: 21]. Simply supply us with your motor power rating, operating speed, driven machine inertia, and shaft dimensions, and our engineering team will provide a 100% compliant replacement specification and quotation[cite: 21].
Core Benchmark Model Standard Configurations
- FLUDEX FAO 222[cite: 21]
- FLUDEX FAO 295[cite: 21]
- FLUDEX FAO 370[cite: 21]
- FLUDEX FAO 425[cite: 21]
- FLUDEX FAO 450[cite: 21]
- FLUDEX FAO 490[cite: 21]
- FLUDEX FAD 295[cite: 21]
- FLUDEX FAD 370[cite: 21]
- FLUDEX FAD 425[cite: 21]
- FLUDEX FAD 450[cite: 21]
- FLUDEX FAD 490[cite: 21]
- FLUDEX FAD 565[cite: 21]
- FLUDEX FVO 450 (Conveyor Duty)[cite: 21]
- FLUDEX FND 450 (ARPEX Output)[cite: 21]
- FLUDEX FADB 450 (Brake Disc)[cite: 21]
- FLUDEX FADS 450 (Brake Drum)[cite: 21]
- FLUDEX FGD 450 (Outer Shell Drive)[cite: 21]
- FLUDEX FAK 425 (V-Belt Pulley)[cite: 21]
- FLUDEX Fusible Safety Plug 140°C[cite: 21]
- FLUDEX EOC Electronic Control Sensor[cite: 21]
