Bright annealed seamless stainless steel coiled tubing in 304/304L, 316L, 321, 317L and 2205 duplex, cold-drawn to precise OD and wall tolerances, supplied in the soft-annealed condition and 100% eddy current tested — manufactured to ASTM A269 / A213.
OD 4 – 25.4 mm · Wall 0.7 – 2.11 mm · Standard coil ≈ 120 kg · Continuous lengths on request
Seamless Coiled Tubing in Continuous Lengths
Bright annealed seamless coiled tubing is produced in continuous lengths with no longitudinal weld seam. Each coil is drawn from a seamless hollow and cold-drawn to precise OD and wall thickness tolerances, then annealed in a controlled protective atmosphere and supplied in the soft-annealed condition. Every coil is 100% eddy current tested before shipment.
Typical uses are instrumentation lines, heat exchangers, chemical and marine sampling lines, and high-purity gas systems.
Key Features
- Seamless, no weld seam: each coil is drawn from a seamless hollow with no longitudinal weld, removing the weld-zone failure risk of welded tubing.
- Cold-drawn precision: cold drawing gives tight OD and wall tolerances, a refined grain structure, and good pressure and bending-fatigue performance.
- Bright annealed surface: annealing in a controlled protective atmosphere prevents scale, leaving a clean, smooth, bright bore and OD that supports corrosion resistance and low flow resistance.
- Soft condition for coiling: delivered soft (HRB ≤ 90 for austenitic grades) for easy bending, coiling and forming.
- Tested per batch: hydrostatic test (10–35 MPa), pneumatic leak test and eddy current test.
- Long lengths: standard coil about 120 kg; longer lengths of several thousand meters are available by orbital butt-welding seamless coils, with weld joints inspected and identified on request.
Technical Specifications
| Product | Bright annealed seamless stainless steel coiled tubing |
|---|---|
| Grades | 304, 304L, 316L, 321, 317L, 2205 duplex |
| Standards | ASTM/ASME A269, A213, A312; also DIN, GB, JIS |
| OD | 4 mm – 25.4 mm |
| Wall thickness | 0.7 mm – 2.11 mm |
| Tolerance | OD ±0.1 mm; WT ±10% |
| Condition | Bright annealed, soft (HRB ≤ 90 for austenitic grades) |
| Coil weight | About 120 kg (varies by size) |
| Testing | Hydrostatic 10–35 MPa, pneumatic, eddy current |
| Documents | EN 10204 3.1 mill test certificate on request |
Typical Applications
- Instrumentation and control: signal lines, impulse lines, pressure tapping lines
- Heat exchangers and condensers: heat transfer coils, boilers, refrigeration, solar collectors
- Petrochemical and marine: chemical injection, sampling and corrosive fluid lines
- Medical and pharmaceutical: high-purity gas and fluid delivery
- Semiconductor and electronics: UHP gas lines (smooth bright bore reduces particle trapping)
How to Choose a Grade
| 304 / 304L | General service, cost-effective |
|---|---|
| 316L | Better chloride and pitting resistance for chemical, marine and pharmaceutical use |
| 321 | Stabilized for sustained high-temperature service |
| 317L | Higher Mo for more aggressive media |
| 2205 duplex | High strength and chloride stress corrosion resistance for offshore and chemical service |
Prepare Your Coiled Tubing Enquiry
Use the following specification format to request a configuration-specific quotation.
- Product: bright annealed seamless coiled tubing
- Grade: [304/304L · 316L · 321 · 317L · 2205 duplex]
- Size: [OD × wall thickness] · Standard: [ASTM A269 / A213 · DIN · GB · JIS]
- Coil weight or continuous length: [kg / m]
- Quantity: [coils or meters] · Testing: [requirements] · Certificate: [EN 10204 3.1]
- Delivery: [destination port]
FAQ: Bright Annealed Seamless Coiled Tubing
Why choose seamless over welded coiled tubing?
Seamless tubing has no weld zone, so wall properties are uniform around the whole circumference. This suits high-pressure, cyclic-load and critical sampling applications.
What does bright annealing do?
Annealing in a protective atmosphere prevents oxidation, so the tube leaves the furnace scale-free with a clean bore. It needs no pickling and has low contamination risk, which suits instrumentation and high-purity systems.
Can you supply continuous lengths longer than 120 kg?
Yes. We orbital butt-weld seamless coils to the length you need. Weld positions can be marked and inspected on request.
Which tests are done before shipment?
Hydrostatic (10–35 MPa), pneumatic and eddy current tests, with an EN 10204 3.1 mill test certificate available on request.
How do I request a quote?
Send grade, OD × WT, standard, quantity and destination port, and we will reply with price and lead time.
