By ORSCO
A 400mm steel oil pipeline that extended from a tank terminal to the wharf at Durban Harbour was in need of rehabilitation. Traditional excavation methods were not going to cut it with the site’s constraints. ORSCO came on board to help with a trenchless rehabilitation solution.
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- One of the challenges was working in a confined space. Images supplied by ORSCO
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- The pipeline in place.
FFS Refiners, a leading provider of hydrocarbon solutions across Africa, required a solution for rehabilitating a 400mm steel oil pipeline extending from their tank terminal to the wharf at Durban Harbour.
Traditional excavation methods were deemed unsuitable due to site constraints, prompting FFS Refiners to engage ORSCO to implement a trenchless rehabilitation solution.
Project scope and challenges
During the initial site assessment, ORSCO determined that 300 metres of the pipeline required rehabilitation. Material testing was conducted at an accredited laboratory to inform the project scope. However, a subsequent site visit revealed a significant challenge: the wharf-side chamber was filled with sediment, obscuring the pipe and necessitating an expansion of the project scope to 330 metres. ORSCO proactively addressed this challenge by arranging for chamber cleaning and procuring the additional materials required, managed through a variation order with the client.
ORSCO attends to pipe rehabilitation.
Solution and Implementation
ORSCO recommended and implemented the ASOE Oil Liner system, a state-of-the-art trenchless technology chosen for its durability, hydrocarbon resistance, and ability to enhance internal pressure capacity while minimising operational disruptions. The project was executed in three key phases:
- Pre-cleaning and Inspection: ORSCO conducted pre-cleaning and desludging operations, including:
- Breaking up solid sediment in the chamber
- High-pressure jetting (subcontracted locally for cost efficiency)
- Desludging of the chamber
- Interim and post-cleaning CCTV inspections to assess pipe conditions
- Handover of the pipeline to FFS Refiners for manual repairs
- Client-led manual repairs: FFS Refiners assumed responsibility for:
- Structural assessments and necessary internal pipeline repairs
- Providing skips for sludge disposal and managing site traffic
- ASOE Oil Liner installation: ORSCO executed the liner installation, encompassing:
- Site establishment and preparation
- Line stringing and pipeline flushing
- Precision installation of the ASOE Oil Liner
- Flanging and securing the liner to the pipe structure
- Site clean-up, waste removal, and final client handover
FFS Refiners conducted the final pressure test post-installation to validate the system’s integrity.
Workers putting shoulder to the grindstone.
Project impact and conclusion
The successful completion of the FFS Refiners pipeline rehabilitation project represents a significant advancement in African pipeline infrastructure. The ASOE Oil Liner’s close-fit design and hydrocarbon resistance provide a long-term, durable solution, ensuring pipeline efficiency and safety.
ORSCO’s expertise in trenchless rehabilitation has established a new benchmark for innovative, non-invasive pipeline repair. The project not only minimised operational downtime for FFS Refiners but also demonstrated a sustainable and cost-effective alternative to traditional excavation methods. The project highlighted ORSCO’s ability to adapt to unforeseen challenges, such as the sediment-filled chamber, and deliver a successful outcome.
Product: ASOE Oil Liner for trenchless rehabilitation on pressure pipes
TECHNICAL SPECIFICATIONS
- TRENCHLESS SOLUTION TYPE: Semi-structural pipe rehabilitation
- ID OF HOST PIPE: DN 50mm – DN 600mm
- MAX LENGTH OF EACH INSTALLATION: Depends on diameter
- MAX OPERATING PRESSURE: 1 – 4 Mpa (10 – 40 bar)
- MAX BURSTING PRESSURE: 3 – 12 Mpa (30 – 120 bar)
- TEMPERATURE OF MEDIUM: 40°C – 70°C
- INSTALLATION MODE: Pull in U-shape liners
- ABRASION RESISTANCE: Tailored to specific application
- WALL THICKNESS: 6mm – 8mm
- PULLING SPEED: Up to 400m/h
- SERVICE LIFE: 40 years
- RAW MATERIALS: High tenacity fabric reinforced layer, abrasion resistant PE cover, oil-resistant PE tube or oil and heat-resistant PVDF tube
