The Complete Guide to Measuring and Replacing Your Industrial Flexible Connectors
1. Measuring the Flange Diameter (OD and ID)
The most critical measurement is not the old sleeve, but the metal flange it attaches to. Old sleeves stretch or shrink over time, making them unreliable templates.
- Outside Diameter (OD): Measure the outer edge of the metal pipe or flange. This ensures the connector snaps or clamps securely.
- Inside Diameter (ID): Essential for maintaining a smooth, "no-crevice" flow. The ID of the connector should match the ID of your piping to prevent powder build-up.
2. Determining the Effective Length (Gap Distance)
The "Gap" is the distance between the top and bottom metal flanges.
- Static Systems: The connector should be approximately 5 percent to 10 percent longer than the gap to allow for ease of installation without excessive sagging.
- Vibrating Systems (Sifters): You must account for the "Throw" or "Stroke" of the machine. The connector needs enough slack to accommodate the maximum oscillation without reaching its physical limit.
3. Choosing the Right Connection Method
How you attach the connector defines your maintenance speed and sealing integrity.
- Hose Clamped (Standard): Ideal for simple gravity drops. Ensure you use high-quality, smooth-edged clamps to avoid cutting the TPU.
- TC Quick-Clip (Sanitary): If your flange has a Tri-Clamp ferrule, the Quick-Clip is the superior choice. It eliminates tools and provides a 100 percent airtight seal instantly.
- FLR Flanges (Bolt-on): Common for square or rectangular hopper outlets. Ensure the bolt-hole pattern matches your existing equipment.
4. Material Selection Based on Application
Before ordering, ask these three questions:
| APPLICATION / CONDITION | RECOMMENDED MATERIAL | KEY PROPERTIES |
|---|---|---|
| General food & powder, ambient | Polyether TPU (PU-10) | Shore A 90, 40 MPa, −20 to +110 °C |
| Abrasive powders, higher pressure | Polyether TPU (PU-15) | Shore A 90, 1.5 mm wall, +0.70 bar / −120 mbar |
| Weighing / loss-in-weight feeders | PU-05-WB bellow | 0.5 mm wall, near-zero reaction force |
| Full vacuum / pneumatic conveying | PU-10-VR | Polymer rings, −1000 mbar |
| Anti-static / ATEX zones | PU-10-AS | 10⁶–10⁹ Ω surface resistivity, no internal wires |
| Strong acids, alkalis, solvents, >150 °C | Pure PTFE | pH 0–14, −40 to +300 °C |
| Hot caustic CIP / washdown | CIP-grade polyether TPU | Hydrolysis-resistant, 85 °C CIP |
Have your measurements ready? Send us your spigot OD, installation gap, powder type and operating temperature — we’ll confirm the correct sleeve + spigot configuration and return a watermarked 2D approval drawing within 24 hours.
→ Email: amin@soshh.com
