S31803 S32205 Duplex Steel Geothermal Coiled Tubing OD 31.8mm

S31803 S32205 Duplex Steel Geothermal Coiled Tubing OD 31.8mm

Specifications

Company and Factory Introduction

MTSCO provides stainless steel and nickel alloy product solutions for global industrial piping projects, serving industries such as oil and gas, chemicals, marine, and heat exchange equipment. For control line products, MTSCO established its own factory, Siri Tubing, in 2024, specializing in the production of welded coiled tubing, geothermal coiled tubing, control line tubing, and multi-core cables, all of which are ISO-certified. Leveraging our in-house manufacturing capabilities, MTSCO ensures more consistent quality control, reliable delivery coordination, and robust project support. We do more than just sell products—we are your trusted supply chain partner.

Manufacturing Process Flow

The core manufacturing process for this geothermal coiled tubing typically includes strip welding, cold drawing, bright annealing, eddy current testing, and hydraulic/air tight testing, followed by precision coiling, marking, and final inspection as per project requirements. For small-diameter control line products, process stability directly impacts weld quality, dimensional consistency, and subsequent installation performance. MTSCO’s in-house facility, Siri Tubing, employs mature processes such as 100% laser welding, cold drawing, bright annealing, and plastic wrapping, making it suitable for the production of continuous-length control lines.

Geothermal Coiled Tubing Final Product Inspection Process

In high-pressure transport applications such as oil and gas, downhole operations, and deep-sea environments, the operational stability of coiled tubing is central to risk management. To this end, MTSCO has established a rigorous final product inspection system to ensure that coiled tubing meets quality standards.

First, the quality team verifies material composition through PMI testing to eliminate the risk of material mix-ups. Second, inspectors conduct rigorous dimensional and visual inspections to ensure the product’s physical specifications fully comply with engineering requirements. Given the continuous-length production process, technicians use Eddy Current Testing (ET) to identify deep-seated defects in the tubing. Subsequently, quality inspectors perform hydrostatic/air tightness tests to verify the product’s pressure integrity under simulated operating conditions. Finally, we test the product in the laboratory to ensure all performance specifications are met.

Hydraulic and Air Tight Test

To verify product reliability under extreme pressure, the production laboratory performs rigorous hydraulic test/air tight test on every coil of finished coiled tubing. Test engineers first seal both ends of the tubing and use a high-pressure pump system to inject water or high-purity nitrogen into the tubing, gradually increasing the internal pressure to multiples of the design standard. During the specified pressure stabilization period, high-precision sensors monitor the pressure curve in real time to confirm that the tubing exhibits no deformation or leakage when simulating deep-sea high-pressure or downhole conditions.

Siri Laboratory

·Weld Radiographic Test Laboratory (RT)

·Chemical Composition Analysis Laboratory

·Intergranular Corrosion Test Laboratory

·Tensile Test Laboratory

·Hardness Test Laboratory

·Metallographic Laboratory

Equipped with professional instruments such as tensile testers, impact testers, metallographic microscopes, and hardness testers, the Siri Laboratory performs mechanical property and non-destructive testing, including tensile, flaring, flattening, bending, hardness, and radiographic testing. All test reports and samples are archived as required to facilitate order traceability, quality verification, and project acceptance.

FAQ

Q1: How is the quality of the coils inspected?

A1: We conduct a three-tier quality inspection process: raw material PMI testing, full traceability throughout the production process, and 100% high-pressure testing plus eddy current testing prior to shipment. All welded coiled tubing must pass rigorous leak testing, and complete inspection records and photographs are retained. MTSCO supports on-site inspections by third-party authoritative agencies to ensure zero-defect delivery for every batch of products.

Q2: In which corrosive environments are welded coiled tubes suitable?

A2: Our duplex stainless steel (2205/2507) is suitable for harsh environments such as seawater desalination, chemical media, and chloride-containing environments. These materials offer excellent resistance to pitting corrosion and stress corrosion cracking. MTSCO can recommend the most cost-effective solution based on your specific application.

Q3: What packaging options are available for the coils? How do you prevent damage during transport?

A3: We offer a variety of packaging options, including plastic reels, wooden reels, solid wooden reels, iron reels, iron and wooden reels, and wooden boxes. We reinforce the coils with wooden strips and ropes when loading them into crates to prevent impact during transport and ensure the goods arrive safely.