English Version (Revised & Checked)
1. Project Overview and Environmental Challenges
The Rumaila Oil Field, one of Iraq’s largest, operates under extremely harsh conditions, including ambient temperatures up to 50 °C, abrasive sandstorms, and highly corrosive soils and produced fluids (e.g. H₂S, CO₂, and chlorides). This project demands materials and components that deliver long-term integrity, minimal maintenance requirements, and robust resistance to corrosion and erosion.
2. Key Advantages of the Specified Components
2.1 Seamless (SMLS) and Cut-to-Length Pipes (½″–48″) with 3LPE Coating
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Superior Corrosion Protection: The 3-layer polyethylene (3LPE) coating system provides a strong barrier against soil moisture, chemical agents, and electrolytic corrosion. The coating-to-steel adhesion strength should be ≥ 15 MPa (or per project-specific requirement), ensuring the coating remains intact through handling and installation.
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Structural Reliability: Seamless pipes have no weld seams, thus eliminating weld-related defects and providing uniform mechanical properties—ideal for high-pressure applications such as injection lines. Cut-to-length pipes, with tolerance ±1 mm, reduce on-site fabrication time and material waste.
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Thermal Stability: The 3LPE system maintains performance across –40 °C to +80 °C, matching typical pipeline thermal cycles and ambient extremes.
2.2 Butt-Weld (BW) Fittings (1″–32″) with 3LPE Coating
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Consistent Corrosion Protection: Pre-coated BW fittings ensure continuity of the corrosion barrier across welded joints, which is critical for buried or splash-zone installations.
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Weld Compatibility: Fittings shall have beveled ends per ASME B16.25, enabling full-penetration welds with minimal defects and preserving coating integrity at weld toes.
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Erosion Considerations: For internal flow lines, a smooth interface reduces flow disturbance. If internal coating or lining is used, the interface to external 3LPE should avoid stress concentration.
2.3 Flanges, Gaskets, Insulation Kits (2″–28″)
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Flange Design & Protection: Available in Raised Face (RF) or Ring‑Type Joint (RTJ) styles, forged per ASTM A105 / LF2. External surfaces may receive galvanizing, epoxy or other suitable corrosion protection, especially in splash or buried zones.
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Gaskets: Spiral-wound gaskets composed of SS 316 and flexible graphite provide a resilient, reliable seal under temperature fluctuations and pressure cycles.
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Insulation Kits: Electrically isolate dissimilar metals (e.g. carbon steel flange vs stainless bolts) to prevent galvanic corrosion at interfaces.
2.4 Stud Bolts and Nuts
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High Strength Fasteners: Use ASTM A193 Grade B7 studs with ASTM A194 2H nuts. Fasteners should be hot-dip galvanized or Xylan-coated (or equivalent) for corrosion resistance, with surface finish controlled to avoid interference with NACE MR0175 hardness limits.
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Preload Accuracy & Seal Integrity: Torque preload tolerance of ±10% ensures controlled gasket compression and uniform flange sealing.
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Vibration & Cycling Resistance: Prevailing-torque (lock) nuts maintain tension under vibration or thermal cycling, commonly found near rotating equipment.
2.5 Y‑Type Strainers, Paddle Blades, and Structural Flat Steel
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Y‑Type Strainers: Fabricated with perforated stainless steel mesh (SS 304/SS 316) and equipped with blow-down valves. These remove sand and debris to protect downstream equipment (control valves, pumps).
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Paddle Blades & Flat Steel: Use abrasion-resistant steels (e.g. AR400 / AR500) for blades in slurry service. Structural flat steel for supports and bracing shall be hot-dip galvanized to resist external corrosion.
3. Project-Specific Benefits
3.1 Corrosion & Abrasion Mitigation
3LPE-coated seamless pipes and fittings extend the service life well beyond 25 years under design conditions, reducing major maintenance interventions. Abrasion-resistant paddles and strainers decrease downtime in sand-laden systems.
3.2 Modularization & Installation Efficiency
Pre-cut, pre-coated components simplify field work, reducing on-site labor by up to 30% and eliminating risks of coating damage from on-site touch-ups. Standardized flange and bolt kits streamline maintenance and spare parts logistics.
3.3 Compliance with International Standards
All materials and coatings conform to key industry standards, including ISO 21809‑1 (external 3LPE coating) , NACE MR0175 / ISO 15156 (sour-service compatibility) resources.nace.org, and ASME B31.4 / B31.8 (pipeline integrity).
4. Conclusion
By integrating 3LPE-coated seamless pipes, butt-weld fittings, flanges, strainers, and abrasion-resistant components, the Rumaila project gains:
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Enhanced Durability: Reliable resistance to corrosion, erosion, and thermal cycling
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Cost Efficiency: Lower maintenance and installation costs through prefabrication and extended lifespan
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Operational Reliability: Greater protection for critical equipment thanks to robust materials and devices
This specification is tailored for Rumaila’s harsh environment, ensuring safe, efficient, and sustainable operations over the long term.
