Duplex Steel 2205 Welded Coiled Tubing with PVDF Encapsulation for Harsh Corrosive Environment
Company & Factory Introduction
Founded in 2006, MTSCO is a leading supplier of industrial stainless steel piping systems, deeply engaged in global engineering and EPC projects through an “integrated factory complex” model. In 2024, MTSCO established its own production base—Siri Tubing—dedicated to the R&D and manufacturing of high-quality welded coiled tubing and multi-core control cables.
Siri Tubing possesses ultra-long continuous production capabilities, with individual coils reaching up to 15,000 meters in length and featuring no butt welds throughout the entire length, significantly reducing on-site installation costs. The factory is ISO-certified and strictly adheres to quality control systems; its products have long served international energy companies such as OXY, KOC, and ADNOC.
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Specification
Item | Details |
Product Type | Welded Coiled Tubing / Encapsulated Control Line |
Material Grade | Duplex Stainless Steel 2205 (S31803/S32205) (316/316L/316Ti, 304/304L, S31803/2205, alloy 625, alloy 825 available) |
Outer Diameter | 3.18-38.1mm (1/8"-11/2") |
Wall Thickness | 0.4-2.54mm (0.016-0.1") |
Length | Up to 15,000m / 50,000 ft per coil |
Standards | ASTM A789 |
Encapsulation Material | PVDF/Polyvinylidene Fluoride (FEP, Rilsan PA 11, Santoprene TPV available) |
Pressure Rating | Up to 15,000 PSI |
Inspection | 100% Hydrostatic Test + Eddy Current Test |
Certificates | ISO 9001 |
Packaging | Plastic Reel, Wooden Reel, Solid Wooden Reel, Iron Reel, Iron & Wooden Reel, Wooden Box |
Why Choose Duplex 2205?
2205 duplex stainless steel is a material composed of approximately 50% ferritic and 50% austenitic stainless steel, offering excellent mechanical properties and corrosion resistance. Compared to standard austenitic stainless steel, 2205 offers approximately 50% higher strength and can withstand greater mechanical stress. Its pitting resistance is significantly superior to that of 316L, with a PREN (Pitting Resistance Equivalent Number) value exceeding 25, making it particularly suitable for use in harsh corrosive environments containing chloride ions and hydrogen sulfide. 2205 duplex steel also exhibits excellent resistance to stress corrosion cracking and performs reliably under high-temperature and high-pressure conditions. For applications such as downhole control lines in oil and gas fields, seawater desalination equipment, and chemical processing, 2205 offers exceptional value for money.
Advantages of PVDF Encapsulation
PVDF is a high-performance fluoropolymer material renowned for its outstanding chemical and weather resistance.
PVDF exhibits extremely high resistance to most chemicals, including strong acids, strong alkalis, oxidizing agents, and halides. It maintains stable performance even in high-temperature environments, with a maximum continuous operating temperature of 150°C. The PVDF encapsulation layer provides dual protection for the internal tubing: first, a physical barrier that prevents corrosive media from coming into direct contact with the metal surface; second, mechanical protection that guards against external damage during installation and use. In highly corrosive environments such as offshore platforms, subsea wells, and chemical processing equipment, PVDF-encapsulated control lines can significantly extend product service life and reduce maintenance costs.
Manufacturing Process Flow
Siri Tubing’s welded coil production begins with high-quality steel strip. Upon arrival at the factory, the raw material undergoes incoming inspection to verify material specifications.
After cleaning, the steel strip enters the forming process, where laser welding is used to form the tube body. Laser welding technology ensures aesthetically pleasing and consistent weld seams. The formed coils then undergo sizing, cold drawing, and in-line bright annealing to improve dimensional accuracy and surface finish. Once the base tube is manufactured, the PVDF coating process begins. The coating is uniformly applied to the tube surface and firmly bonded to the tube material. Finally, the tubes undergo precision winding, marking, final inspection, and packaging.
Quality Control System | Quality Control System
Siri Tubing has established a comprehensive three-tier quality control system:
Raw Material Re-inspection: All raw materials are sourced from qualified suppliers of internationally renowned steel mills such as POSCO, Yakin, and Outokumpu. Each batch of materials must be accompanied by a Material Test Certificate (MTC), and upon arrival, a re-inspection via spectrometer (PMI) is conducted to verify composition.
Traceable Production Process: From laser welding, cold drawing, and annealing to coating, every process step is supervised on-site by QC inspectors and documented with photographs. Process cards are used throughout the entire process to ensure traceability at every stage.
100% Pre-shipment Inspection: A dedicated QC team conducts a series of inspections on every coil, including appearance, dimensions, PMI, eddy current testing, and hydrostatic testing. All products must pass 100% hydrostatic testing and are available for third-party inspections by SGS, TÜV, and BV.
FAQ
Q1: For what operating conditions is 2205 duplex steel suitable?
A1: 2205 duplex steel is suitable for oil and gas wells containing corrosive media such as chloride ions and hydrogen sulfide, as well as highly corrosive environments such as seawater desalination and chemical processing. It offers high strength and excellent resistance to pitting corrosion and stress corrosion cracking.
Q2: Do you offer third-party inspections?
A2: Yes. We accept on-site inspections by authoritative third-party organizations such as SGS, TÜV, and BV.
Q3: What is the maximum length of continuous coiled tubing you can provide?
A3: Siri Tubing can provide continuous lengths of up to 15,000 meters (approximately 50,000 feet) per coil, reducing the number of on-site joints and enhancing system reliability.
Q4: Do you offer customization?
A4: Yes. We can customize the outer diameter, wall thickness, length, and packaging material according to customer requirements, including non-standard sizes and special specifications.