High-Efficiency FDD-500BB ANFD Double Cartridge Seal
High-Efficiency FDD-500BB ANFD Double Cartridge Seal
Overview
HydroMax Seal FDD-550BB | Exotic Alloy Double Cartridge Seal for ANFD Applications
The FDD-550BB is an exotic alloy multi-spring double cartridge seal with hydraulically balanced seal faces. The “550BB” model features an integral bearing, metal bellows, and Hastelloy wetted parts.
This Rotary Pusher Double Cartridge Seal includes monolithic seal faces, an integral bearing, and O-ring secondary seals, specifically designed for Agitated Nutsche Filter Dryers (ANFDs).
The mechanical seal is equipped with multi-springs, a set screw drive, and quench and drain port connections.
The FDD-550BB accommodates significant axial shaft movement via a specially designed inboard metal bellows. The bellows length is customized to match the vertical movement of the ANFD paddle or agitator.
The seal has a number of design features, comes factory assembled and tested, and has been successfully installed in hundreds of applications.
Product Description
Technical Specifications
| Seal Shaft Sizes | 1.18″ – 7.87″ (further sizes can be designed as required) |
| Inboard Seal Face Combinations | Car/TC Car/SiC SiC/SiC |
| Outboard Seal Face Combinations | Car/TC Car/SiC |
| Gasket | GFT / Graphite |
| Bellows | Hastelloy (Length to suit ANFD paddle movement) |
| Inboard Wetted Parts | Hastelloy |
| Elastomers | Viton ERP Aflas Kalrez |
| Shaft Speeds | Up to 10 m/s |
| Pressures | Up to 6 barg (90 psig) – Shaft Size Specific |
| Temperatures | Up to 200°C (392°F) |
Supply Options
316 Stainless Steel, Hastelloy, or Exotic Alloy wetted parts
Plan 52/53 Seal Support System with cooling coil and finned tubing
Plan 54 Seal Support System (forced barrier fluid circulation for high heat removal)
WARNING:
The safe seal performance characteristics are typical values for each variable in isolation. The individual upper limit values of speed, pressure, and temperature should NOT be used in combination.
Typical Applications & Industry Use Cases
The FDD-550BB Exotic Alloy Double-Cartridge Seal is engineered for the most demanding rotating-shaft systems—especially where corrosive media, high temperature, and axial movement are present. Its exotic alloy-wetted parts (Hastelloy) combined with an integral bearing, metal bellows design, and hydraulically balanced faces make it a premium choice for processes where standard materials simply do not suffice.
Industries Served
Pharmaceutical and fine-chemical plants
Agitated Nutsche Filter Dryers (ANFDs) with aggressive solvents and batch processing.
Specialty chemical and petrochemical plants
Reactors, mixers, and dryers handling corrosive or high-temperature chemistry.
Mining and mineral processing
Large-shaft agitators in abrasive or corrosive slurries where exotic alloys deliver longevity.
High-duty processing environments
Wherever a double seal is required with exotic wetted parts for reliability under stress.
Equipment & Use-Case Scenarios
- Vertical ANFD systems whose paddle shafts undergo significant axial travel, where the metal-bellows inboard section accommodates movement.
- Horizontal dryers, large mixers, or reactors where expansion, shaft run-out, and corrosive environments are simultaneous challenges.
- Vacuum filtration or drying operations that demand exotic materials, low-leakage barriers, and double seal redundancy.
- Applications where standard stainless steel seals fail prematurely and a long-life, exotic-alloy solution is required to maintain uptime and lower total cost of ownership.
Why It Fits These Applications
- The metal bellows inboard section effectively absorbs axial movement, helping maintain face alignment even under vertical paddle movement or shaft travel.
- Exotic alloy-welded parts (Hastelloy) resist corrosion and high-temperature attack, ensuring performance where lesser alloys would degrade.
- Balanced seal faces and cartridge-style construction give the FDD-550BB extended service life and robust performance under harsh conditions.
- The design supports advanced support systems (e.g., forced barrier circulation) for high heat removal and complex process demands.
Installation Guidelines
Ensure that the shaft and mounting surfaces are properly prepared: cleaned, aligned, and within tolerance before the cartridge is inserted.
Install the cartridge seal without forcing the bellows section—allow the bellows to perform as designed and absorb axial movement naturally.
Orient the quench and drain ports correctly in the seal support system layout, and commission the appropriate barrier or flushing circuit (Plan 52, Plan 53, or Plan 54, as applicable to your process).
Tighten the set screws and secure the gland/clamp per the OEM standard instructions; verify that the barrier fluid or quench circuits are ready before startup.
Confirm that all elastomers and exotic alloy wetted parts match your process conditions (temperature, pressure, media compatibility) prior to operation.
Maintenance & Inspection Best Practices
- During operation, periodically inspect the seal chamber for any signs of leakage, contamination, crystallization, or buildup of deposits.
- Monitor barrier fluid (or quench fluid) pressure, temperature, and flow to ensure the seal faces remain properly lubricated and cooled.
- Inspect the metal bellows section at planned intervals for signs of fatigue, deformation, or corrosion—especially in high-temperature or aggressive environments.
- On scheduled shutdowns, remove the cartridge (if applicable) to inspect and replace secondary O-rings and gaskets. Record the wear pattern of the seal faces to determine future replacement intervals.
- Maintain a service log that tracks shaft speeds, process media changes, seal face replacement, and support-system performance to maximise reliability and plan proactive maintenance.
Service & Support Options
HydroMax Seal provides full lifecycle support for the FDD-550BB model:
- Pre-installation consultation for proper seal specification (including exotic alloy selection, bellows length, and flushing/quench plan).
- Field or remote installation guidance and commissioning assistance to help ensure integration into your system.
- Spare parts kits tailored for the cartridge configuration (including seal faces, O-rings, gaskets) and exotic alloy wetted parts.
- Upgrade pathways, including moving to enhanced support systems (e.g., forced barrier fluid circulation) if your process evolves or conditions intensify.
- Long-term maintenance programmes designed to minimise downtime, extend the life-cycle, and improve return on investment for uptime-critical equipment.
With correct installation and proactive maintenance, the FDD-550BB delivers outstanding performance in demanding environments, combining exotic-alloy robustness with engineered movement accommodation for reliable operation in ANFDs, dryers, reactors, and mixed-media systems.
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Contact HydroMax Seal
Contact HydroMax Seal today for innovative solutions, expert guidance, and over a century of engineering excellence. Your journey to mechanical sealing excellence starts with HydroMax Seal!
E-Mail: sales@hydromaxseal.com
Address: 18511 Beaumont Hwy Building D
Houston, TX
77049
