Overview
The Flex-A-Seal 3442-C21 is a Style 34 (SB1) stationary welded metal bellows cartridge mechanical seal designed for pump shaft and rotating equipment sealing. Constructed from 316 stainless steel, this rotary bellow head assembly delivers dependable performance in demanding industrial applications including petrochemical, pharmaceutical, food processing, and general pump sealing where corrosion resistance and temperature stability are critical.
Key Features
- Welded metal bellows design eliminates seal hang-up and shaft fretting common in pusher-type seals
- Stationary cartridge configuration simplifies installation and reduces downtime
- 316 stainless steel construction for superior corrosion resistance in harsh environments
- Pre-assembled and pressure-tested by manufacturer prior to shipment
- Single-piece cartridge design—no field assembly required
- Compatible with high-temperature, cryogenic, and corrosive applications
Technical Specifications
- Part Number: 3442-C21
- Seal Style: Style 34 (SB1) – Stationary Welded Bellows Cartridge
- Material: 316 Stainless Steel (bellows)
- Seal Type: Single cartridge, stationary rotary bellows
- Elastomers Available: Viton, Ethylene Propylene, Aflas, Buna, Neoprene, Perfluoroelastomers
- Sealing Faces: Antimony Impregnated Carbon, Nickel Bound Tungsten Carbide, or Silicon Carbide
- Configuration: Rotary bellow head assembly
- Condition: New in Box
- Manufacturer: Flex-A-Seal, Inc. (Essex Junction, VT)
Typical Applications
- Centrifugal pump shaft sealing in refinery and chemical processing plants
- Food and beverage processing equipment requiring FDA-approved sealing
- Pharmaceutical manufacturing with strict contamination control requirements
- Paper pulp processing and bleach applications (high-temperature environments)
- Wastewater treatment and municipal water pump systems
- HVAC chilled water and condenser water loops
- Vacuum and cryogenic fluid handling equipment
Compatibility & Replacements
Compatible With
- Single-cartridge seal glands designed for Style 34 or SB1 configurations
- Pump manufacturers using Flex-A-Seal OEM specifications
- Industrial pump housings rated for welded bellows cartridge seals
- Equipment originally equipped with Flex-A-Seal rotary bellows assemblies
Replaces / Drop-In Replacement For
- Verify compatibility with your system integrator or equipment OEM before ordering to ensure gland dimensions and seal bore match your specific pump model. Flex-A-Seal distributes this seal under part number 3442-C21; confirm whether your equipment calls for this exact configuration.
Works With
- Flex-A-Seal repair and rebuild services available through authorized distributors
- Compatible with Flex-A-Seal sealing software and selection guides for specification verification
- Works with OEM pump documentation specifying Style 34 or stationary welded bellows seals
- Integrates with predictive maintenance monitoring for mechanical seal performance
