Nickel Alloy UNS N06625 Heat Exchanger Straight Tube With Abrasion Resistance
Company Profile
MTSCO is a one-stop supplier of stainless steel and nickel alloy piping systems serving global EPC firms, engineering companies, and end-users. Our product range includes seamless pipes, pipe fittings, flanges, plates, and control lines. In 2024, MTSCO established its own production facility—Siri Tubing—dedicated to the R&D and manufacturing of high-strength stainless steel and nickel alloy welded coils. For heat exchanger straight tubes, MTSCO leverages the factory’s welded tube manufacturing capabilities to provide a complete delivery solution, ranging from raw material control and bending/welding to heat treatment, inspection, and export packaging.
Manufacturing Process Flow
Heat exchanger straight tube uses steel coils as raw material. After slitting and bending, the material proceeds directly to automated welding and in-line annealing, enabling continuous and efficient production. Subsequently, the tubes undergo end facing, pickling, non-destructive testing, marking, final inspection, and packaging for storage. MTSCO’s heat exchanger straight tubes undergo 100% full-coverage inspection via in-line eddy current testing, with full process traceability, ensuring that every tube complies with international standards.
Specification
Item | Specification |
Product Type | Welded Tube / Heat Exchanger Straight Tube |
Grade | Alloy625/ UNS N06625 (304/304L, 316/316L/ 316Ti, S31803/2205, S332750/2507, alloy 825 available) |
Standards | ASTM B704 |
Outside Diameter | 6 - 25 mm (1/8" - 1") |
Wall Thickness | 0.5 - 3 mm (0.02" - 0.118") |
Length | ≤12 m |
Inspection | Appearance / Dimensional Test, PMI, NDT: UT / ET |
Finish | Bright Annealed (BA)/ Annealed Pickling (AP) |
Certificates | ISO |
Package | Plywood crate + individual plastic bag wrapping + end caps on both sides |
Solution Annealing
Solution annealing is the heat treatment process that determines the final corrosion resistance and microstructure of the heat exchanger tube. Residual stresses generated during the welding process are eliminated through solution annealing, allowing the material to regain its ductility and corrosion resistance. Our heat exchanger straight tubes undergo continuous solution annealing via an in-line annealing process, ensuring higher efficiency and uniform temperature distribution. Currently, MTSCO’s solution-annealed heat exchanger straight tubes have been delivered in bulk to multiple international heat exchanger projects.
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Quality Control System
·Secondary Inspection of Raw Materials: Raw materials are sourced from major steel mills such as JISCO and TSINGSHAN, with each batch accompanied by an MTC and PMI. Upon arrival at the factory, a secondary verification is conducted to ensure that the material grade and chemical composition meet order specifications.
·Full Process Traceability: Every stage—bending, welding, annealing, and pickling—is documented with process cards and QC photographs, ensuring that the production records for every tube are verifiable and traceable.
·100% Pre-shipment Inspection: The MTSCO quality inspection team conducts comprehensive testing of finished products, including appearance, dimensions, PMI, and eddy current testing. We support third-party inspections by SGS, TÜV, and BV.
Online Eddy Current Testing
Online eddy current testing is a critical inspection step for ensuring the surface and near-surface quality of small-diameter welded pipes. After automatic welding and online annealing, automated eddy current testing equipment performs a 100% full-length scan of the pipe body, enabling real-time detection of defects such as wall thickness anomalies, longitudinal cracks, and pinholes without physical contact with the pipe.
The eddy current testing system features high sensitivity, capable of detecting minute defects. MTSCO’s online ET testing effectively reduces the risk of defective products entering subsequent processing stages, ensuring batch consistency of the final product.
FAQ
Q1: What is the maximum delivery length for straight tubes?
A1: Standard straight tube lengths are ≤12m. For longer sections, coiled tube configurations are available (Siri Tubing offers a maximum single coil length of 15,000m). MTSCO supports customization of lengths and shapes according to project requirements.
Q2: How do you ensure product quality fully matches the specifications?
A2: MTSCO implements end-to-end quality tracking from raw materials to finished products. We conduct PMI test and ultrasonic/eddy current non-destructive testing. We welcome customers to designate third-party inspectors such as SGS or TÜV for verification, and we commit to “zero-defect” delivery.
Q3: For which operating conditions are nickel alloy heat exchanger tubes suitable?
A3: 316L can meet the requirements of most mildly corrosive media, but high-temperature steam-side or strongly acidic environments typically require nickel alloys such as Alloy 625/825, which offer significantly higher high-temperature strength and corrosion resistance than stainless steel.