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ISO 28017:2026 Rubber Hoses for Dredging — Specification
Wire and textile reinforced rubber hoses and hose assemblies for dredging applications
ISO 28017:2026 specifies comprehensive requirements for wire-reinforced and textile-reinforced rubber hoses and hose assemblies used in dredging applications, covering construction, materials, dimensional tolerances, pressure ratings, test methods, and marking. This fourth edition standard addresses the extreme operating conditions encountered in dredging operations, including highly abrasive slurries, high working pressures, continuous flexing, seawater immersion, UV exposure, and the dynamic loading conditions typical of floating and submerged pipeline systems.
Dredging hoses operate in one of the most demanding industrial environments. They handle highly abrasive sand, gravel, and rock slurries at pressures up to 70 bar while being continuously flexed by wave action, currents, and vessel movement, dragged across rough surfaces, and submerged in seawater for extended periods.
Hose Classification, Construction, and Material Requirements
The standard classifies dredging hoses by working pressure rating (Classes A through D), reinforcement type (textile, wire, or combined), and application category (discharge, suction, or floating). Each classification has specific construction requirements including tube material (abrasion-resistant natural or synthetic rubber with minimum tear resistance), reinforcement layers (braided or spiraled steel wire or high-tenacity synthetic textile), cover material (weather, ozone, UV, and abrasion-resistant rubber), and end fitting types (raised-face flanges, swivel flanges, or quick-connect couplings). Floating hoses require additional buoyancy layer specifications.
| Class | Working Pressure Range (bar) | Reinforcement Type | Min Burst Pressure (bar) | Typical Application |
|---|---|---|---|---|
| Class A | 10-20 | Textile (polyester or nylon) | 40 | Light-duty suction and discharge, small dredgers |
| Class B | 20-35 | Wire braid + textile ply | 100 | Medium-duty dredging, sand and gravel |
| Class C | 35-52 | Heavy spiral wire | 150 | Heavy-duty discharge, rock pumping |
| Class D | 52-70 | Multiple spiral wire layers | 210 | High-pressure deep dredging, >50m depth |
| Floating | 10-25 | Textile with closed-cell foam buoyancy | 60 | Floating pipeline systems, tender vessels |
Mixing hose classes within a single dredging pipeline creates weak points at the transition. All hoses in a continuous pipeline string must be rated at or above the maximum system working pressure, and end fitting compatibility must be verified across different manufacturers to ensure secure connections.
Performance Testing and Quality Assurance Requirements
ISO 28017 specifies two levels of testing. Type tests for design validation include burst pressure verification at 4x working pressure, flexing fatigue testing for minimum cycle life, adhesion testing between hose components, low-temperature flexibility at -20°C, and ozone resistance. Routine production tests include hydrostatic pressure testing at 1.5x working pressure, dimensional verification of inside diameter and flange drilling template, and visual examination. Each hose must be permanently marked with the standard reference, classification, working pressure, test pressure, date of manufacture in YYYY-MM format, manufacturer name or trademark, and serial number for traceability.
Modern ISO 28017-compliant dredging hoses achieve service lives of 3-5 years in continuous operation, representing a 40-60% improvement over non-standardized hoses. Proper material selection and class specification based on the specific dredging application are critical to achieving these service lives.
End Fitting Design and Connection Integrity
A critical engineering consideration is end fitting retention force. The standard specifies minimum pull-off test forces for swaged or clamped connections based on hose bore diameter and working pressure class. Connection design must account for dynamic loading from wave action, current forces, and vessel movement in floating dredging operations.
Q: What is the difference between wire-reinforced and textile-reinforced dredging hoses?
A: Wire-reinforced hoses provide higher pressure ratings, better kink resistance, and greater dimensional stability, while textile-reinforced hoses offer superior flexibility, lighter weight for handling, and better corrosion resistance in marine environments.
A: Wire-reinforced hoses provide higher pressure ratings, better kink resistance, and greater dimensional stability, while textile-reinforced hoses offer superior flexibility, lighter weight for handling, and better corrosion resistance in marine environments.
Q: How should dredging hoses be stored during non-operational periods?
A: Hoses should be stored in a cool, dry environment away from direct sunlight, ozone-generating equipment, and sharp objects, in their natural curvature without sharp bends or kinks, and ideally on hose racks or wooden pallets.
A: Hoses should be stored in a cool, dry environment away from direct sunlight, ozone-generating equipment, and sharp objects, in their natural curvature without sharp bends or kinks, and ideally on hose racks or wooden pallets.
Installation, Maintenance, and Service Life Optimization
Proper installation and maintenance practices significantly extend dredging hose service life. ISO 28017 provides guidance on minimum bend radius requirements during installation, proper flange bolt tightening procedures using calibrated torque wrenches, and support spacing for horizontal pipeline layouts. Floating hoses require additional consideration of buoyancy distribution, mooring arrangements, and abrasion protection at contact points with the vessel or dredger.
Regular inspection and maintenance programs should include daily visual inspection for cover damage, leakage, or unusual deformation; monthly thickness measurement at wear-prone areas using ultrasonic gauges; quarterly pressure testing of assembled strings; and annual replacement of hose sections showing significant wear. The standard recommends maintaining an inventory log tracking each hose’s service hours, pressure cycles, and inspection results to enable predictive replacement scheduling.
Q: What causes premature dredging hose failure?
A: The most common causes are operating above rated pressure, excessive flexing below minimum bend radius, external abrasion from contact with dredger hull or pipeline supports, and ozone cracking of the cover material in hot climates.
A: The most common causes are operating above rated pressure, excessive flexing below minimum bend radius, external abrasion from contact with dredger hull or pipeline supports, and ozone cracking of the cover material in hot climates.
Q: How should damaged hoses be handled in the field?
A: Minor cover damage can be temporarily repaired using manufacturer-approved vulcanized patches, but any damage exposing the reinforcement layer requires immediate hose replacement. Field repairs of the reinforcement or tube are not permitted under the standard.
A: Minor cover damage can be temporarily repaired using manufacturer-approved vulcanized patches, but any damage exposing the reinforcement layer requires immediate hose replacement. Field repairs of the reinforcement or tube are not permitted under the standard.
Environmental Considerations and End-of-Life Management
ISO 28017 addresses environmental considerations throughout the hose lifecycle. The standard encourages use of environmentally preferred materials in hose construction, specifies testing for leaching of harmful substances into surrounding water, and provides guidance on end-of-life management including recycling options for rubber materials. Dredging operators should establish procedures for proper disposal of worn-out hoses and consider take-back programs offered by hose manufacturers for material recycling.
Selection Criteria for Dredging Hose Applications
Selecting the appropriate dredging hose requires systematic evaluation of operating conditions including material characteristics of the dredged slurry (particle size, shape, hardness, concentration), operating pressure and flow velocity, pipeline configuration (straight runs, bends, vertical sections), environmental conditions (water temperature, wave action, UV exposure), and mechanical loading (tension from pipeline movement, abrasion from seabed contact). The standard provides selection matrices that guide engineers to the appropriate hose class and construction type for each application scenario.
