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Shanghai Toko Tech Co., Ltd. is a professional manufacturer and supplier of high-quality special alloy pipes and components. While renowned for its seamless products, TOKO TECH also provides 316L welded coiled tubing, offering a cost-effective solution for applications requiring excellent corrosion resistance, particularly against chlorides, while benefiting from the economic advantages of the welding process and the installation convenience of long continuous lengths.
Key Features & Advantages:
Excellent Corrosion Resistance: Inherits the superior corrosion resistance of 316L austenitic stainless steel. The addition of Molybdenum (2-3%) significantly enhances resistance to pitting and crevice corrosion in chloride-ion environments, outperforming 304/304L grades.
Low Carbon Content (L-Grade): The carbon content is controlled to a maximum of 0.03%, minimizing the risk of sensitization (chromium carbide precipitation) during the welding process itself. This ensures good intergranular corrosion resistance in the weld zone without the need for post-weld annealing.
Cost-Effectiveness: Welded tubing typically has a lower production cost compared to seamless tubing, providing an economical alternative for projects where the extreme pressure ratings of seamless tubing are not required, but core material properties and long lengths are essential.
Continuous Coiled Length: Supplied in long continuous coils, eliminating multiple connection points and simplifying installation in systems requiring long runs, complex routing, or bending around obstacles.
Good Formability and Weldability: The base material is easy to form and weld, allowing for flexibility in fabrication and installation.
Manufacturing Process & Quality Focus:
The tubing is formed from precision-rolled 316L strip, which is then longitudinally welded using advanced Tungsten Inert Gas (TIG) or Laser Welding processes under protective atmosphere to ensure a clean, high-integrity weld. A critical step is the annealing and pickling of the finished coil. This process dissolves carbides that may have formed during welding, restores the corrosion resistance in the weld heat-affected zone (HAZ), and ensures a uniform, passive surface finish.
Typical Specifications (Customizable):
Material Grade: UNS S31603 / EN 1.4404 / ASTM A269 TP316L
Outer Diameter (O.D.): φ6.0 mm ~ φ25.0 mm (Common range for welded coils)
Wall Thickness (W.T.): 0.5 mm ~ 2.0 mm (Varies with O.D.)
Coil Length: Several hundred meters per continuous coil.
Standard: ASTM A269 (Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service)
| Theoretical Pressure Parameters for 316L coiled Tubing | |||||
| Type | O.D. (in) | W.T. (in) | Max. Theoretical Working Pressure (psi) | Min. Theoretical Collapse Pressure (psi) | Nominal Theoretical Burst Pressure (psi) |
| Welded | 1/4 | 0.035 | 6188 | 6500 | 18542 |
| 1/4 | 0.049 | 9011 | 8554 | 25833 | |
| 1/4 | 0.065 | 12659 | 10599 | 34375 | |
| 1/4 | 0.083 | 17269 | 12430 | 43958 | |
| 3/8 | 0.035 | 4006 | 4563 | 12438 | |
| 3/8 | 0.049 | 5743 | 6131 | 17329 | |
| 3/8 | 0.065 | 7908 | 7806 | 23059 | |
| 3/8 | 0.083 | 10523 | 9476 | 29488 | |
| 1/2 | 0.035 | 2965 | 3512 | 9365 | |
| 1/2 | 0.049 | 4218 | 4765 | 13048 | |
| 1/2 | 0.065 | 5754 | 6141 | 17362 | |
| 1/2 | 0.083 | 7574 | 7566 | 22202 | |
| Notes: *Theoretical collapse pressure based on nominal OD, average wall thickness and minimum yield strength. *Theoretical burst pressure based on nominal OD, average wall thickness and minimum tensile strength. *Theoretical working pressure utilizes a 1.33 S.F. (Safety Factor) from theoretical yield point. |
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Primary Applications:
This welded coiled tubing is suitable for a variety of applications where corrosion resistance is paramount, but maximum pressure capability is not the primary concern, including:
Chemical and Petrochemical Processing: Transfer lines for mild corrosive chemicals, instrument air lines, sample lines.
Pharmaceutical and Bio-Processing: Process lines for high-purity water, intermediate product transfer, where cleanliness and corrosion resistance are critical.
Food and Beverage Industry: Conveying process fluids, ingredients, and CIP (Clean-in-Place) systems.
Marine and Coastal Applications: Low-pressure system components exposed to saltwater atmospheres.
General Industrial: Hydraulic lines, pneumatic control systems, and instrumentation in moderately corrosive environments.
Why Choose TOKO TECH’s 316L Welded Coiled Tubing?
TOKO TECH ensures the quality of its welded product through stringent control. The process includes 100% weld seam inspection (via eddy current or laser testing) to ensure integrity and consistency. The mandatory full coil solution annealing and pickling & passivation treatment is crucial for maximizing corrosion resistance, especially in the critical weld zone. The coils are typically protected with VCI (Vapor Corrosion Inhibitor) packaging to prevent surface corrosion during transit and storage.
In summary, TOKO TECH’s 316L welded coiled tubing provides a reliable and cost-efficient solution for applications demanding excellent chloride resistance and good overall corrosion performance. It combines the material benefits of 316L with the economic and installation advantages of welded coiled tubing, making it a valuable choice for engineers in the chemical, pharmaceutical, food, and marine industries for medium-pressure duties.