SOSHH® FLC Round Flange Flexible Connector | Heavy-Duty Food-Grade PU Expansion Sleeves
The SOSHH® FLC round flange flexible connector is an ultra-durable, zero-leakage elastomeric expansion sleeve engineered specifically for rigid flanged piping, heavy-duty vibratory screeners, bin activators, and continuous pneumatic conveying lines. Featuring integrated molded polyurethane flanges at both ends, the FLC sleeve clamps securely between standard equipment companion flanges and metal backing pressure plates. Fabricated from 100% FDA-compliant virgin Ether-grade Polyurethane (TPU), it delivers superior abrasion resistance, high pressure/vacuum stability, and permanent ATEX anti-static safety with zero tooling fees for custom diameters and bolt hole patterns.
![FLC round flange PU flexible connector sealing details and gasket design]()
1. Engineered for High-Sealing Reliability & Demanding Flange Interfaces
In high-vibration powder screening, positive-pressure pneumatic conveying, and dense-phase bulk transfer, conventional rubber sleeves or hose-clamped connections can slip off, develop rim tears, or allow fine dust escape. The SOSHH® FLC Round Flange Connector provides a mechanically locked, bolted elastomeric barrier that eliminates clamping failure.
Zero-Tolerance Pressure & Vacuum Resistance
By compressing the integrated PU flange collar directly between the pipe flange and heavy-duty metal backing rings, the FLC series withstands continuous operating pressures up to +0.8 bar and deep vacuum conditions down to -0.5 bar without blowouts or inward sleeve collapse.
Seamless High-Frequency Heat-Fused Construction
Manufactured using high-frequency thermal welding rather than stitching or adhesive bonding, the FLC connector features a 100% smooth, crevice-free internal bore. This eliminates internal ledges where bulk solids accumulate, preventing microbial growth and supporting Clean-In-Place (CIP) washdown procedures.
2. Comprehensive Material Selection & Engineering Matrix
| Technical Parameter | Standard Food-Grade (PU10) | ATEX Anti-Static (PUAS) | High-Temperature (PUHT) | Fiber-Reinforced (PURF) | Wire-Reinforced (PUFL) |
| Primary Material | 100% Virgin Ether TPU | Anti-Static Ether TPU | Thermal-Stabilized TPU | Multi-Ply Fiber TPU | TPU w/ SS304 Spiral Wire |
| Material Color | Crystal Clear | Crystal Clear | Light Amber | Clean Optical White | Translucent White |
| Wall Thickness | 1.0 mm (0.04") | 1.0 mm (0.04") | 1.0 mm (0.04") | 0.8 mm (0.03") | 0.6 mm to 1.5 mm |
| Operating Temp | -20°C to +110°C | -20°C to +110°C | -20°C to +150°C | -20°C to +110°C | -20°C to +110°C |
| Surface Resistivity | > 10^12 Ohm | < 10^9 Ohm (ATEX) | > 10^12 Ohm | > 10^12 Ohm | > 10^12 Ohm |
| Tensile Strength | 40 MPa | 15 MPa | 40 MPa | 300 MPa (Heavy Duty) | 40 MPa |
| Elongation at Break | 600% | 600% | 600% | 600% | 600% |
| DIN Abrasion Loss | 39.0 mg | 39.0 mg | 35.0 mg | 39.0 mg | 35.0 mg |
| Air Permeability | 100% Airtight | 100% Airtight | 100% Airtight | 100% Airtight | 100% Airtight |
| Food Compliance | FDA / EU Certified | FDA / EU Certified | FDA / EU Certified | FDA / EU Certified | FDA / EU Certified |
| Ideal Application | General powder drop | Combustible fine dust | Hot air drying chutes | High-pressure blowers | High-amplitude gyratory |
3. Performance Benchmark: SOSHH® FLC vs. Conventional Hose-Clamped Sleeves
| Engineering Feature | SOSHH® FLC Bolted Round Flange Sleeve | Conventional Hose-Clamp Flexible Sleeves | Standard Rubber Expansion Joints |
| Connection Security | Bolted metal pressure plate (Cannot slip off) | Worm-drive clamps vibrate loose over time | Heavy bolted assembly |
| Pressure Stability | High positive/negative pressure resistant | Prone to slipping under minor backpressure | High pressure capability |
| Abrasion Resistance | 3 to 5x longer service life than rubber | Low (Tears easily at clamp pressure zones) | Standard |
| Optical Clarity | 100% Transparent (Visual flow monitoring) | Opaque or cloudy | Opaque black |
| Sanitary Compliance | FDA 21 CFR 177.2600 & EU 10/2011 | Varies; stitching harbors bacteria | May leach oils or black carbon |
4. Primary Industrial Application Scenarios
Vibratory Screeners & Gyratory Sifters
Absorbs continuous high-frequency multi-axis mechanical oscillation between screener discharge spouts and downstream fixed chutes without developing stress cracks at the flange junction.
Positive & Negative Pressure Pneumatic Conveying
Maintains airtight containment on blower discharge lines, cyclone separators, and rotary airlock feeder connections where pressure surges dislodge standard clamp-on sleeves.
Bulk Bag & FIBC Loading Chutes
Provides a durable, dust-tight interface for mobile filling heads and bulk packaging stations handling abrasive grains, mineral powders, and pharmaceutical granules.
5. 3-Step Standard Flange Installation Protocol
- Step 01: Flange AlignmentEnsure mating pipe flanges are clean, flat, and aligned within standard axial tolerances. Place the lower and upper integrated PU flanges of the FLC sleeve against the equipment faces.
- Step 02: Position Backing PlatesPlace the split metal pressure plates (backing rings) over the integrated PU flange cuffs to distribute bolt clamping torque uniformly around the circumference.
- Step 03: Cross-Pattern FasteningInsert flange bolts and hand-tighten. Torque all bolts sequentially in a diagonal cross-pattern to the recommended torque specification to achieve a uniform, airtight compression seal.
Product Features
Compatible with standard round interfaces with built-in flanges at both ends
It is tightly connected by two flange pressure plates pressed in the middle
Suitable for high sealing reliability requirementsand equipment points that don't need to be disassembled frequently
![FLC round flange flexible connector assembly and installation diagram]()
Installation Instructions
Fit the flange pressure plate on the flexible hose, then tighten the bolts at both ends in sequence to complete the installation.
6. Factory-Direct Customization: Zero Tooling Fees & Free 3D CAD
As a specialized engineering manufacturer of flexible connection systems, SOSHH® manufactures FLC round flange sleeves to your exact equipment geometry:
- Custom Diameters & Bolt Circles: Fabricated to match ANSI 150#, DIN PN10/PN16, JIS, or custom proprietary OEM bolt patterns from DN100 to DN1200 (4" to 48").
- Custom Installed Heights (L): Built to the millimeter (from 80mm to 1500mm) to match your exact installation gap without line modifications.
- Zero Tooling Fees: No mold or setup fees for non-standard diameters or custom flange widths.
- 24-Hour Engineering CAD Verification: Complimentary 2D dimensional drawings and 3D CAD models (STEP/IGES) provided within 24 hours.
7. Frequently Asked Questions (FAQ)
Q1: Is the FLC connector safe for Clean-In-Place (CIP) washdowns?
Yes. The smooth, hydrophobic Ether-based TPU material supports standard CIP caustic and mild acid rinse cycles without swelling, hardening, or degrading.
Q2: Which material option is best for high vacuum lines?
For high negative pressure systems (-0.3 bar to -0.8 bar), we recommend our PURF (Fiber-Reinforced TPU) with 300 MPa tensile strength or PUFL (Spiral Stainless Steel Wire Reinforced TPU) to completely prevent inward wall collapse.
Q3: Can FLC replace legacy bolted rubber connectors without modifying existing pipework?
Yes. We manufacture the FLC series with custom bolt hole counts, pitch circle diameters (PCD), and flange outer diameters to drop directly into existing flanged piping without cutting or welding.
Q4: Are anti-static options available for ATEX explosive dust environments?
Yes. Our PUAS material option provides certified permanent surface resistivity below 10^9 Ohm, safely dissipating electrostatic charges generated during high-speed powder transfer in ATEX Zone 20/21/22 zones.
8. Request a 24-Hour Custom Engineering Proposal
- Technical Desk: Email your flange outer diameter (OD), pitch circle diameter (PCD), bolt hole count/size, installed gap (L), and powder media details to amin@soshh.com.
- Global Express Dispatch: Direct international air shipping to North America, Europe, Asia-Pacific, and the Middle East.
(Trademark Disclaimer: SOSHH® is an independent registered brand of Zhejiang Jingzhen Environmental Protection Technology Co., Ltd. References to standard flange patterns or legacy equipment models are strictly for technical cross-reference and dimensional compatibility.)
![Food-grade industrial certification labels for Jingzheng flexible connectors, including SGS and CNAS quality assurance.]()
