FlowTex™ Dewatering Tubes

Dewatering Tubes Fabricated to the Project, Not the Catalogue

FlowTex dewatering tubes are large-format geotextile containers for volume dewatering of tailings, sludge, dredged sediment and process residues. Where bags handle discrete 1 m³ volumes, tubes handle continuous or campaign dewatering measured in hundreds or thousands of cubic metres - filled over days or weeks, dewatered in place, and either disposed of intact or cut open for removal of consolidated solids.

Multiple fill ports. Tubes are fabricated with inline fill ports distributed along the length, so the tube fills progressively rather than from a single point. This matters in practice: single-port filling builds a solids cone at the inlet that blocks flow long before the tube is full, wasting capacity and forcing early shutdown. Staged filling across multiple ports distributes the solids load, uses the full tube volume and lets the operator move the feed as each section consolidates. Port count and spacing are set by tube length and slurry characteristics.

Fabric and grade selection. Slit film woven from 40 kN/m to 105 kN/m, for coarse to medium solids where tensile capacity under filling pressure is the governing requirement. Monofilament woven at a controlled 180 µm opening, where sustained flow through multi-fill cycles matters and a slit film tube would blind. Composite construction pairing a needlepunched nonwoven inner with a woven outer shell, separating filtration duty from structural duty so retention can go finer than a single-layer woven allows. Grade selection follows filling pressure and tube diameter - internal pressures are highest on large-diameter units, which is where the 105 kN/m grade earns its specification.

Construction. Seams are sewn with GORE™ TENARA® thread, a UV-stable ePTFE sewing thread that holds strength through prolonged exposure. On a tube dewatering in the open for weeks, seam degradation is the failure that ends the job, and it is the failure standard polyester thread invites. Double-stitch lock seams achieve 70% seam efficiency against fabric tensile. Fill ports are reinforced at the fabric interface.

Fabricated in-house. Tubes are made to project dimensions in our own facility in Johannesburg - diameter, length, fabric grade and port configuration set by the application, not selected from a fixed size list. That capability is the difference between specifying a tube that suits the site and adapting the site to an imported standard size.

Geosynthetics Africa fabricates and supplies across South Africa and the wider continent. Our technical team will match slurry characteristics, target dry solids and dewatering duration to tube sizing, fabric grade and polymer requirement.