Dewatering Systems
FlowTex™ - Geotextile Dewatering Bags
Geotextile dewatering bags in 1m × 1m × 1m format, available in slit film woven, monofilament woven and composite fabric constructions. Sewn with GORE™ TENARA® UV-stable thread, double-stitch lock seams at 70% seam efficiency, and integrated lifting slings rated to 2 tonnes. Nominal capacity 1 m³ of filtrate. Fabricated in South Africa, supplied continent-wide.
Overview
Dewatering Bags Built to Survive the Seam, Not Just the Fill
FlowTex is a range of geotextile dewatering bags in a standard 1m × 1m × 1m format, supplied in three fabric constructions so the filtration specification can be matched to the slurry rather than to whatever is in stock. Each bag holds a nominal 1 m³ of filtrate.
Construction - common to every FlowTex bag. Seams are sewn with GORE™ TENARA® thread, a UV-stable ePTFE sewing thread that holds its strength through prolonged sun exposure. This matters more than it sounds: the usual failure mode on a dewatering bag is not the fabric but the stitching, where standard polyester thread degrades in the sun while the geotextile around it is still sound. Seams are double-stitch lock construction achieving 70% seam efficiency against fabric tensile. Integrated lifting slings are rated to handle a filled bag at 2 tonnes, so a full bag can be lifted and relocated intact rather than cut open and rehandled.
Fabric selection. FlowTex HF uses flat-tape slit film woven polypropylene - the economical specification for coarse to medium sediment on short-cycle work such as construction runoff and stormwater pond clean-outs. FlowTex Mono uses round continuous monofilament yarns at a controlled 180 µm opening size; the round-yarn pore structure stays open as fines accumulate, which makes it the specification for mine tailings, dredged sediment, municipal sludge and any long-duration or multi-fill application where flow rate must be sustained. FlowTex Duo pairs a needlepunched nonwoven inner liner with a woven outer shell, separating filtration from structural duty so retention can go finer than a single-layer woven allows - for ultra-fine clays and process residues where filtrate clarity governs discharge compliance.
These are three answers to three different questions, not a good-better-best ladder. Our technical team will match fines content, volume and project duration to the correct fabric, so you neither pay for filtration you don't need nor blind a bag on a job that needed more.
Supply and QA. Fabricated in South Africa from imported fabric, with mill test certificates and QA documentation on every order. Tensile and opening size tested to ASTM D4595 and ASTM D4751. Geosynthetics Africa supplies across South Africa and the wider continent on a single specification and lead time.
- MaterialWoven polypropylene (PP) · slit film, monofilament or composite
- StructureSlit film woven · monofilament woven 180 µm · nonwoven-lined composite
- ColourBlack / Grey
- StandardASTM D4595 tensile · ASTM D4751 AOS · ISO 9001 manufacture
- Roll Width1.00 m × 1.00 m bag footprint · 2 t rated lifting slings
- Roll Length1.00 m height · 1 m³ nominal filtrate capacity
Typical Properties
| Property | FlowTex HF WG30 | FlowTex HF WG45 | FlowTex HF WG60 | FlowTex HF WG105 | FlowTex Mono 40 |
|---|---|---|---|---|---|
| Fabric Type | Slit film woven PP | Slit film woven PP | Slit film woven PP | Slit film woven PP | Monofilament woven PP |
| Tensile Strength (MD/CMD) | 30 kN/m biaxial | 45 kN/m biaxial | 60 kN/m biaxial | 105 kN/m biaxial | 40 kN/m biaxial |
| UV Stabilisation | Yes | Yes | Yes | Yes | Yes |
| Infill Ports | Reinforced | Reinforced | Reinforced | Reinforced | Reinforced |
| Opening Size (AOS) | Coarse | Coarse | Coarse | Coarse | 180 Micron |
| Clogging Resistance | Standard | Standard | Standard | Standard | High, non-clogging |
| Suitable Particle Size | Coarse to medium | Coarse to medium | Medium | Medium | Fine silt and clay |
| Multi-fill Capable | Yes | Yes | Yes | Yes | Yes |
| Origin | South Africa | South Africa | South Africa | South Africa | South Africa |
Note: The above specifications represent the product family properties. Please refer to the product datasheet for individual SKU values.
Typical Applications
View all applicationsMine Tailings Dewatering
FlowTex Mono is the correct specification for mine tailings dewatering where fine particle content is high and extended dewatering duration is required. The non-clogging monofilament fabric maintains flow rate through multi-fill cycles. FlowTex HF WG105 suits large-diameter tube installations where high tensile strength is the priority.
Construction Site Dewatering
FlowTex HF bags in WG30HF and WG45HF grades are suited to pump-out water treatment, stormwater sediment removal, and short-duration dewatering on active construction sites. Fast local supply supports project mobilisation timelines.
Wastewater and Sludge Dewatering
FlowTex Mono tubes and bags handle biological sludge, municipal wastewater solids, and industrial process waste effectively. The controlled 180 micron opening size retains fine organic particles while producing clear effluent suitable for recirculation or compliant discharge.
Industrial Slurry Management
FlowTex HF WG60 and WG105 tubes suit medium to large volume industrial slurry containment and dewatering where high tensile performance and local supply availability are required. Compatible with polymer conditioning for difficult-to-dewater process slurries.
Compatible Systems
View all systemsFlowTex HF Dewatering Bags
Slit film woven polypropylene dewatering bags in standard and custom sizes for construction site dewatering, stormwater sediment management, and general slurry containment. Available in WG30HF and WG45HF fabric grades with reinforced infill ports and UV-stabilised threads. Suited to coarser particle applications where high flow rate takes priority over fine particle retention.
FlowTex HF Dewatering Tubes
High-strength slit film dewatering tubes available in WG30HF, WG45HF, WG60HF, and WG105HF fabric grades. The WG105HF grade at 105 kN/m biaxial tensile is the highest strength locally manufactured slit film dewatering tube available in southern Africa, suited to large-diameter installations under high filling pressures. All tubes feature reinforced infill ports and UV-stabilised construction.
FlowTex Mono Dewatering Bags
Monofilament woven polypropylene dewatering bags with 180 micron controlled opening size and non-clogging pore structure. Rated at 40 kN/m tensile strength with enhanced seam construction. The correct specification for fine silt, clay-rich slurries, mine tailings, and long-duration dewatering where slit film bags would blind and lose flow rate over time.
FlowTex Mono Dewatering Tubes
Large-format monofilament woven polypropylene dewatering tubes for medium to large volume applications requiring sustained filtration performance under sustained solids loading. Non-clogging fabric maintains hydraulic efficiency through multi-fill cycles, making FlowTex Mono Tubes the preferred specification for tailings management, industrial sludge, and wastewater lagoon cleanout projects.
Installation Guidance
Standard Method Statement
FlowTex dewatering bags are deployed on a stable, prepared surface with adequate drainage fall to direct effluent away from the containment area. Position the bag with the infill port orientated to receive the slurry feed from a pump or gravity line. Secure the bag at the base to prevent displacement during filling. Fill at a controlled rate matched to the fabric permeability and slurry characteristics. Do not exceed the design fill height as overfilling stresses seams and reduces fabric life. Where slurry contains significant fine particles, polymer dosing upstream of the bag inlet will improve filtration performance and effluent clarity. FlowTex Mono fabric is the correct specification for high-fines applications where sustained flow rate must be maintained. Dewatered bags must be allowed to drain fully before handling, and disposed of in accordance with the waste classification of the retained solids.
Select and prepare a level containment area capable of supporting the filled weight of the tube, with an impermeable base liner to capture and redirect effluent to a collection point. Unroll the tube along its full intended length before filling begins, with all infill ports orientated upward. Connect pump supply lines to the infill ports and verify connections before starting. Conduct a Jar Test prior to filling to confirm polymer type, dosage, and compatibility with the slurry chemistry. Fill at a controlled rate to avoid overpressurising the fabric, particularly on large-diameter WG105HF units where internal pressures are highest. Allow adequate dewatering time between fill cycles before refilling. Dewatered tubes are disposed of in accordance with the waste classification of the retained solids, or cut open for mechanical removal of consolidated material where beneficial reuse or landfill disposal is planned.
Quality Assurance & Testing
Field QA/QC Checklist
- Material Conformance: Fabric certificates checked for tensile strength, seam strength (ASTM D4884) and opening size; dewatering performance confirmed by a hanging bag (ASTM D7701) or GDT test (ASTM D7880) with the actual sludge and polymer.
- Laydown Area: Area levelled and lined with a drainage layer and, where required, a geomembrane to collect filtrate.
- Filling: Fill ports connected; fill height monitored against the manufacturer's maximum; flocculant dose controlled.
- Filtrate Monitoring: Filtrate clarity and solids monitored; tubes inspected for seam or fabric distress during filling.
Manufacturing Standards
- ASTM D7880 geotextile dewatering test (GDT)
- ASTM D7701 hanging bag test
- ASTM D4884 seam strength
- Manufacturer filling guide
- ASTM D4595 tensile · ASTM D4751 AOS · ISO 9001 manufacture
Documents
Product Selection Guide
Compare performance properties across the entire category hierarchy before specifying.
Installation & Method Statement
Standard deployment procedures, installation specifications, and field application method statements.
QA/QC Site Checklist
Field quality control procedures, inspection checklists, and testing standards to verify installation integrity.
Technical Data Sheet (TDS)
Guaranteed minimum average roll values (MARV) and material testing properties.
Chemical Resistance / Accessories Guide
Chemical compatibility matrix and list of auxiliary materials needed for installation.
Projects Using FlowTex™ - Geotextile Dewatering Bags
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