stainless steel
coil tube
TeCarve’s Stainless Steel Helical Coil Tube is designed for superior flexibility, durability, and efficiency in heat transfer and fluid systems. Manufactured with precision coiling technology, our tubes offer continuous length, smooth internal surfaces, and excellent corrosion resistance, making them ideal for critical industrial and sanitary applications.
These coil tubes reduce welding joints, minimize leakage risks, and ensure long-lasting performance under high pressure and temperature conditions. Available in a wide range of grades such as 304, 316L, and 321, they meet the diverse needs of chemical, food & beverage, pharmaceutical, and marine industries.
With strict dimensional tolerances, advanced testing, and compliance with ASTM, EN, JIS, and GB standards, TeCarve delivers helical coil tubes that combine reliability, efficiency, and global-standard quality.
Custom Stainless Steel Helical Coil Tubes for Compact Heat Transfer
Specifications
Available Specifications by Standard Matrix
Markets: N. America — seamless small-diameter helical coil tube (heat exchanger/instrumentation)
| OD (mm) | WT (mm) | OD Tol. | WT Tol. |
|---|---|---|---|
| 1.59 | 0.20 | +0.10mm / −0.11mm | ±10.0% |
| 3.18 | 0.35 | +0.10mm / −0.11mm | ±10.0% |
| 6.35 | 0.71 | +0.10mm / −0.11mm | ±10.0% |
| 9.53 | 0.89 | +0.10mm / −0.11mm | ±10.0% |
| 12.70 | 1.24 | +0.10mm / −0.11mm | ±10.0% |
| 19.05 | 1.65 | +0.10mm / −0.11mm | ±10.0% |
| 25.40 | 2.11 | ±0.15mm | ±10.0% |
OD tolerance per ASTM A1016/A1016M Table 3 (welded & cold-finished seamless tubes). Wall thickness tolerance per ASTM A213/A213M §13.2 (cold-formed, ±10% of specified wall).
- Supply Length / Form: Pre-formed helical coils to specified coil OD/pitch/turns, or continuous coil stock up to 1,500m
- Available Grades: 304, 304L, 316, 316L, 321, 904L, duplex 2205 / 2507
- Surface Finish: Bright annealed (Ra ≤ 0.4μm internal bore available), annealed & pickled, or mechanically polished
- Tolerance Compliance: ASTM A213 / A269 / A632, ASME B31.3, PFI ES-24, TEMA RCB-2.32, EN 10216-5
Markets: N. America — small-diameter seamless & welded corrosion-resisting helical coil tube
| OD (mm) | WT (mm) | OD Tol. | WT Tol. |
|---|---|---|---|
| 1.59 | 0.20 | ±0.13mm | ±15.0% |
| 3.18 | 0.35 | ±0.13mm | ±15.0% |
| 6.35 | 0.71 | ±0.13mm | ±15.0% |
| 9.53 | 0.89 | ±0.13mm | ±15.0% |
| 12.70 | 1.24 | ±0.13mm | ±15.0% |
| 19.05 | 1.65 | ±0.13mm | ±10.0% |
| 25.40 | 1.65 | ±0.13mm | ±10.0% |
Per ASTM A269/A269M Table 4 (self-contained — not A1016-derived). Group 1 (OD ≤12.7mm): ±0.13mm / ±15% wall. Group 2 (12.7–38.1mm): ±0.13mm / ±10% wall.
- Supply Length / Form: Pre-formed helical coils to specified coil OD/pitch/turns, or continuous coil stock up to 1,500m
- Available Grades: 304, 304L, 316, 316L, 321, 904L, duplex 2205 / 2507
- Surface Finish: Bright annealed (Ra ≤ 0.4μm internal bore available), annealed & pickled, or mechanically polished
- Tolerance Compliance: ASTM A213 / A269 / A632, ASME B31.3, PFI ES-24, TEMA RCB-2.32, EN 10216-5
Markets: Europe, Middle East — small-diameter precision helical coil tube
| OD (mm) | WT (mm) | OD Tol. | WT Tol. |
|---|---|---|---|
| 4.0 | 0.5 | ±0.10mm (±2.5%) | ±0.06mm (±12.5%) |
| 6.0 | 1.0 | ±0.15mm (±2.5%) | ±0.13mm (±12.5%) |
| 10.0 | 1.5 | ±0.15mm (±1.5%) | ±0.19mm (±12.5%) |
| 14.0 | 1.5 | ±0.15mm (±1.1%) | ±0.19mm (±12.5%) |
| 21.3 | 2.3 | ±0.20mm (±0.9%) | ±0.29mm (±12.5%) |
- Supply Length / Form: Pre-formed helical coils to specified coil OD/pitch/turns, or continuous coil stock up to 1,500m
- Available Grades: 304, 304L, 316, 316L, 321, 904L, duplex 2205 / 2507
- Surface Finish: Bright annealed (Ra ≤ 0.4μm internal bore available), annealed & pickled, or mechanically polished
- Tolerance Compliance: ASTM A213 / A269 / A632, ASME B31.3, PFI ES-24, TEMA RCB-2.32, EN 10216-5
Markets: Japan, Southeast Asia — small-diameter boiler/instrumentation helical coil tube
| OD (mm) | WT (mm) | OD Tol. | WT Tol. |
|---|---|---|---|
| 6.0 | 1.0 | ±0.30mm (±5.0%) | ±0.13mm (±12.5%) |
| 10.0 | 1.2 | ±0.30mm (±3.0%) | ±0.15mm (±12.5%) |
| 12.7 | 1.65 | ±0.30mm (±2.4%) | ±0.21mm (±12.5%) |
| 21.7 | 2.0 | ±0.40mm (±1.8%) | ±0.25mm (±12.5%) |
- Supply Length / Form: Pre-formed helical coils to specified coil OD/pitch/turns, or continuous coil stock up to 1,500m
- Available Grades: 304, 304L, 316, 316L, 321, 904L, duplex 2205 / 2507
- Surface Finish: Bright annealed (Ra ≤ 0.4μm internal bore available), annealed & pickled, or mechanically polished
- Tolerance Compliance: ASTM A213 / A269 / A632, ASME B31.3, PFI ES-24, TEMA RCB-2.32, EN 10216-5
Markets: China domestic & Belt-and-Road — small-diameter precision helical coil tube
| OD (mm) | WT (mm) | OD Tol. | WT Tol. |
|---|---|---|---|
| 6 | 1.0 | ±0.10mm (±1.7%) | ±0.13mm (±12.5%) |
| 10 | 1.5 | ±0.10mm (±1.0%) | ±0.19mm (±12.5%) |
| 14 | 2.0 | ±0.14mm (±1.0%) | ±0.25mm (±12.5%) |
| 20 | 2.5 | ±0.20mm (±1.0%) | ±0.31mm (±12.5%) |
| 25 | 2.5 | ±0.25mm (±1.0%) | ±0.31mm (±12.5%) |
- Supply Length / Form: Pre-formed helical coils to specified coil OD/pitch/turns, or continuous coil stock up to 1,500m
- Available Grades: 304, 304L, 316, 316L, 321, 904L, duplex 2205 / 2507
- Surface Finish: Bright annealed (Ra ≤ 0.4μm internal bore available), annealed & pickled, or mechanically polished
- Tolerance Compliance: ASTM A213 / A269 / A632, ASME B31.3, PFI ES-24, TEMA RCB-2.32, EN 10216-5
1. Seamless Coiled Tubing: Minimum Bend Radius (R/D Ratio) & Wall Thinning Limits
When bending cold-drawn seamless stainless steel tubing into compact helical coils, the centerline bend radius R must be precisely matched to tube outside diameter D and nominal wall thickness t. According to PFI Standard ES-24 (Pipe Fabrication Institute) and ASME B31.3 Table 332.1.1, exceeding the plastic bending strain limit leads to severe outer extrados thinning, throat buckling, or cross-sectional collapse.
Requires R ≥ 2.5D to 3.0D (Coil mean diameter Dc ≥ 5D–6D). Tube cross-section remains naturally stable during continuous multi-roll coiling without internal filling or mandrels, preserving continuous lengths up to 1,500m.
When space constraints require tight curves down to R = 1.5D to 2.0D, TeCarve deploys internal multi-ball flexible mandrels, wiper dies, and booster carriage compression to keep extrados thinning within 15%–17%.
Theoretical outer back-wall thickness follows TEMA RCB-2.32 rule: tmin = tnom × [1 − D/(4R)]. Boosted CNC bending maintains actual thinning ≤ 12%–15%, well within ASME Section VIII requirements.
| Tube OD (D) | Nominal WT (t) | D/t Ratio | Min. Centerline Radius R (Mandrel Bending R ≥ 1.5D–1.8D) | Min. Centerline Radius R (Continuous Roll Coiling R ≥ 2.5D–3.0D) | Min. Coil Mean Dia. (Dc) | Typical Extrados Thinning |
|---|---|---|---|---|---|---|
| 1/4″ (6.35 mm) | 0.89 mm (0.035″) | 7.1 | 10.0 mm (1.57D) | 16.0 mm (2.52D) | 32 mm | ≤ 14% (Ultrasonic checked) |
| 3/8″ (9.53 mm) | 0.89 mm (0.035″) | 10.7 | 15.0 mm (1.57D) | 25.0 mm (2.62D) | 50 mm | ≤ 15% (UT verified) |
| 1/2″ (12.70 mm) | 1.24 mm (0.049″) | 10.2 | 20.0 mm (1.57D) | 35.0 mm (2.76D) | 70 mm | ≤ 15% (Ultrasonic checked) |
| 5/8″ (15.88 mm) | 1.24 mm (0.049″) | 12.8 | 25.0 mm (1.57D) | 45.0 mm (2.83D) | 90 mm | ≤ 16% (UT verified) |
| 3/4″ (19.05 mm) | 1.65 mm (0.065″) | 11.5 | 30.0 mm (1.57D) | 55.0 mm (2.89D) | 110 mm | ≤ 16% (Ultrasonic checked) |
| 1″ (25.40 mm) | 2.11 mm (0.083″) | 12.0 | 45.0 mm (1.77D) | 75.0 mm (2.95D) | 150 mm | ≤ 17% (TEMA RCB-2.32 limit) |
2. Cross-Sectional Ovality (Roundness) & Coil Geometry Control
Cross-sectional out-of-roundness (ovality) directly impacts fluid flow resistance, Dean vortex stability, and internal pressure containment. Ovality is governed by the universal pipe bending index:
Exceeds ASME B31.3 Section 332.2.1 and PFI ES-24 requirements. Eliminates localized hydraulic dead spots in oil chillers, tank heaters, and steam recovery loops.
Calibrated by precision multi-roll CNC guides to ensure stable refrigerant vaporization and predictable pressure drops in subcooled evaporators.
Engineered for Water-for-Injection (WFI) and aseptic bioreactors. Delivers uniform velocity profiles, complete drainability, and zero residue trapping.
3. Hydrostatic Test Standards & Proof Pressure Calculations
Every helical coil and coiled tube assembly receives 100% NDT, with hydrostatic testing per the applicable standard or order, before shipment. In accordance with ASTM A269 Section 10, ASTM A213 Section 14, and ASTM A1016 Section 24, test pressures are strictly calculated via Barlow’s Formula:
For 304L/316L (SMYS = 205 MPa / 30,000 psi), fiber stress S = 140 MPa (20,400 psi). For Duplex 2205 (SMYS = 450 MPa), S = 306 MPa. Mill proof pressure is rated up to 20.7 MPa (3,000 psi) unless higher pressure is specified.
Standard holding time is 5–10 seconds (meeting the ASTM 5 s minimum), with no pressure drop or leakage observed during the hold.
Completed coils undergo auxiliary pneumatic bubble leak testing at 0.7–1.0 MPa (100–150 psi) dry nitrogen submerged in illuminated clear water tanks for 15–30s to detect micro-pinholes.
Direct Product Hub: Heat Transfer & Coiled Tubing Lines
Source complementary tubing products with full mill traceability and engineering drawings:
Stainless Steel Coiled Tube
Long continuous coiled tubing up to 1,500m on wooden or steel reels for hydraulic impulse lines, subsea umbilicals, and downhole chemical injection.
Heat Exchanger Pipe & Tube
Straight and U-bent tubes per ASTM A213 / A249 / A688 with localized solution annealing, close-fit tolerances, and 100% NDT inspection.
Stainless Steel Low Fin Tube
Integrally rolled finned tubes expanding external heat transfer area by 2.5× to 3.5× for industrial chillers and refrigeration condensers.
TeCarve operates strictly under certified ISO 9001:2015, ISO 14001:2015, and ISO 45001:2018 management systems. All stainless steel helical coil tubing is delivered with genuine EN 10204 3.1 Mill Test Certificates (MTC) verifying melt chemical analysis, mechanical tensile and yield values, elongation, hardness, flattening, flaring, and 100% NDT inspection results (eddy current and hydraulic proof testing). International standards compliance includes ASTM A213, ASTM A269, ASTM A632, ASME B31.3, PFI ES-24, and EN 10216-5. Third-party inspection and witness testing by SGS, Bureau Veritas (BV), or TÜV can be coordinated upon client request.
Get Your Helical Coil Tube Quote
Sourcing custom spiral or helical wound stainless steel coil tubing for heat exchanger vessels, immersion heating/cooling, distillation condensers, or reaction jacket loops? Contact our sales engineering desk for live mill pricing, tight coil pitch/radius control, seamless continuous runs, and flexible trial orders (100–300 kg MOQ supported).
Fast engineering calculations, CNC mandrel tooling review, and material pricing within 2 hours.
Short helical coil sample segments provided for coil pitch, bend curvature, and fitting alignment trials.
Verify vessel chamber fit, fluid flow drop, and mounting bracket tolerances with low-MOQ trial coils.
100% NDT with hydrostatic testing per standard/order, ovality/thinning inspection, and full EN 10204 3.1 certification.
Standards
→ Scroll right for full chemistry & mechanical data
| Grade | US (UNS) | EN (W.Nr.) | Japan (JIS) | China (GB/T) | C % (Max) | Si % (Max) | Mn % (Max) | P % (Max) | S % (Max) | Cr % | Ni % | Mo % | Tensile σb (Min.) | Yield σ0.2 (Min.) | Elongation (Min.) | Hardness (Max) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2205 Duplex* | S32205 | 1.4462 | SUS329J3L* | 022Cr23Ni5Mo3N* | 0.030 | 1.00 | 2.00 | 0.030 | 0.020 | 22.0-23.0 | 4.5-6.5 | 3.0-3.5 | 655 MPa (95 ksi) | 450 MPa (65 ksi) | 25% | ≤31 HRC / ≤293 HB |
| 304 | S30400 | 1.4301 | SUS304 | 06Cr19Ni10 | 0.08 | 0.75 | 2.00 | 0.045 | 0.030 | 18.0-20.0 | 8.0-11.0 | — | 515 MPa (75 ksi) | 205 MPa (30 ksi) | 35% | ≤92 HRB / ≤215 HV |
| 304L | S30403 | 1.4307 | SUS304L | 022Cr19Ni10 | 0.030 | 0.75 | 2.00 | 0.045 | 0.030 | 18.0-20.0 | 8.0-12.0 | — | 485 MPa (70 ksi) | 170 MPa (25 ksi) | 35% | ≤92 HRB / ≤215 HV |
| 316 | S31600 | 1.4401 | SUS316 | 06Cr17Ni12Mo2 | 0.08 | 0.75 | 2.00 | 0.045 | 0.030 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | 515 MPa (75 ksi) | 205 MPa (30 ksi) | 35% | ≤95 HRB / ≤215 HV |
| 316L | S31603 | 1.4404 | SUS316L | 022Cr17Ni12Mo2 | 0.030 | 0.75 | 2.00 | 0.045 | 0.030 | 16.0-18.0 | 10.0-14.0 | 2.0-3.0 | 485 MPa (70 ksi) | 170 MPa (25 ksi) | 35% | ≤95 HRB / ≤215 HV |
| 321 | S32100 | 1.4541 | SUS321 | 06Cr18Ni11Ti | 0.08 | 0.75 | 2.00 | 0.045 | 0.030 | 17.0-19.0 | 9.0-12.0 | — | 515 MPa (75 ksi) | 205 MPa (30 ksi) | 35% | ≤95 HRB / ≤215 HV |
| 409 | S40900 | 1.4512 | SUS409 | 022Cr12Ti | 0.03 | 1.00 | 1.00 | 0.040 | 0.020 | 10.5-11.75 | — | — | 380 MPa (55 ksi) | 205 MPa (30 ksi) | 20% | ≤88 HRB / ≤190 HV |
| 410 | S41000 | 1.4006 | SUS410 | 12Cr13 | 0.15 | 1.00 | 1.00 | 0.040 | 0.030 | 11.5-13.5 | — | — | 450 MPa (65 ksi) | 205 MPa (30 ksi) | 20% | ≤96 HRB / ≤210 HV |
| 430 | S43000 | 1.4016 | SUS430 | 10Cr17 | 0.12 | 1.00 | 1.00 | 0.040 | 0.030 | 16.0-18.0 | — | — | 450 MPa (65 ksi) | 205 MPa (30 ksi) | 22% | ≤89 HRB / ≤200 HV |
| 904L* | N08904 | 1.4539 | N/A | 015Cr20Ni18Mo6CuN* | 0.020 | 1.00 | 2.00 | 0.045 | 0.035 | 19.0-23.0 | 23.0-28.0 | 4.0-5.0 | 490 MPa (71 ksi) | 215 MPa (31 ksi) | 35% | ≤90 HRB / ≤200 HV |
- Standards Conformance: ASTM A213/A269/A632 · EN 10216-5/10217-7 · DIN 17458 · JIS G3448/G3463 · GB/T 13296/14976
- Delivery Condition: Solution Annealed & Pickled (AP) / Bright Annealed (BA) / Polished, or as requested.
- Mill Test Certificate: 100% full material traceability with EN 10204 3.1 MTC provided with every shipment.
- Cross-Reference Note: 2205 duplex and 904L JIS/GB cross-reference figures are compiled from secondary industry sources — please confirm exact specification and heat-specific mill test certificate with TeCarve for critical applications.
Features
• Continuous coil length, fewer joints
• High flexibility and easy installation
• Excellent corrosion and pressure resistance
• Smooth internal bore for fluid and gas flow
• Heat exchangers and condensers
• Instrumentation and control lines
• Food and pharmaceutical fluid transfer
Applications
For specialized helical and spiral coil tubing, see how customers can verify our CNC bending accuracy, ovality control, post-bending annealing, and pressure-test records.
Quality Control
• Raw material traceability with mill certificates
• Eddy current and hydraulic proof testing
• Precise dimensional inspection and ovality control
• Surface roughness and corrosion resistance checks
• Third-party inspection available upon request
packaging
PVC Wrapping
& End Caps
Custom Barcoding
& Labeling
Anti-Corrosion
& Moisture Protection
Seaworthy Wooden Cases & Pallets
Helical Coil Tube Production & Shipping Photos
Real product, inspection, packaging and loading photos.
Tailored Solutions, Timely Fulfillment
CUSTOMIZATION
& DELIVERY
Flexible Custom Manufacturing
We customize stainless steel helical coil tube by outer diameter, wall thickness, continuous coil length, seamless or welded construction, grade, and annealed, pickled, polished, mirror, or satin finish.
Low MOQ & Rapid Prototyping
MOQ is as low as 100–300 kg for flexible trial orders, with small batch customization and sample production supported, helping you shorten your development cycle and market entry.
Optimized Lead Time
In-stock standard sizes ship within 7–10 days. Custom specifications typically ship within 10–25 days after deposit, depending on order volume, dimensions, and surface finish. The full cycle—from inquiry and drawing confirmation through sampling, production, inspection, and dispatch—typically takes 33–55 days for custom items.
Global Logistics & On-Time Delivery
For helical coil tube exports worldwide, PVC wrapping and anti-corrosion and moisture protection safeguard the coil, with seaworthy pallets supporting secure handling.
How your order is made, checked and shipped
Tube forming at the partner factory
Heat treatment (annealing)
Dimensional inspection
Alloy verification with a handheld analyzer
Export packing
Container loading
What Overseas Buyers Say About TeCarve Tubing
“I've received the goods and everything is fine.”
“The goods already send to customers. I am waiting for the next order from them.”
“…there is no need of inspection this time… I trust in your product.”
Frequently Asked Questions
What is a stainless steel helical coil tube?
A helical coil tube is a stainless steel tube wound into a tight helical (spring-like) coil. When immersed in a tank or vessel, it provides a large heat transfer surface in a compact footprint. The helical geometry creates secondary Dean vortex flow that can improve heat transfer by 30–50% over straight tubes of equal length.
What coil dimensions does TeCarve supply for helical coil tubes?
Helical coil tubes are custom-manufactured to customer specifications: tube OD from 1.6 mm to 25.4 mm, wall thickness from 0.3 mm to 3 mm, and continuous coil lengths up to 1500 meters where applicable. Coil geometry is designed to customer thermal calculations and vessel drawings. Both seamless and welded tube construction are offered.
What grades are used for stainless steel helical coil tubes?
Available in grades 304, 316L, 316, 321, 904L, and duplex 2205/2507. Grade 316L is standard for chemical reactors, pharmaceutical tanks, and brewery vessels. Grade 904L and super duplex 2507 are used in concentrated acid and high-chloride environments.
How are inlet and outlet connections made on helical coil tubes?
Coil inlets and outlets are straight tube extensions terminating in ANSI/DIN flanges, NPT/BSP threaded connections, or tri-clamp sanitary ends. Connection configuration and nozzle orientation are designed to customer piping arrangement drawings.
What industries use stainless steel helical coil tubes?
Helical coil tubes are used in chemical reactors, pharmaceutical fermenters and bioreactors, food and dairy processing tanks, breweries, oil & gas heat exchangers, geothermal heating systems, and any application requiring compact immersion heating or cooling within a tank or vessel.
What is the minimum bend radius (R/D ratio) for stainless steel helical coil tubes?
For cold-drawn seamless stainless steel helical coils, the centerline bend radius (R) relative to tube outer diameter (D) is governed by PFI Standard ES-24 and ASME B31.3. For continuous multi-roll coiling or rotary draw bending without internal mandrels, a minimum bend radius of R ≥ 2.5D to 3.0D (coil mean diameter Dc ≥ 5D–6D) is standard to prevent wall collapse and intrados wrinkling. When compact vessel designs require tighter curves down to R = 1.5D–2.0D, TeCarve deploys internal multi-ball flexible mandrels and wiper dies with booster feeding, keeping outer extrados wall thinning strictly under 15%–17% per TEMA RCB-2.32 rules.
How is cross-sectional ovality (roundness) controlled in helical coil tubing?
Cross-sectional ovality is calculated as [(ODmax - ODmin) / ODnominal] × 100%. While general piping codes like ASME B31.3 Section 332.2.1 allow up to 8%–10% out-of-roundness under internal pressure, TeCarve standard industrial coils maintain ovality ≤ 6.0%. Precision heat exchanger and refrigeration grade coils are calibrated to ≤ 4.0%, and sanitary bio-pharmaceutical coils (WFI/bioreactors) achieve ≤ 2.5%–3.0% via internal ball-mandrel sizing for uniform fluid velocity and good drainability.
What proof pressure testing standards apply to stainless helical coil tubes?
Every helical coil undergoes 100% hydraulic proof testing per ASTM A269 Section 10, ASTM A213 Section 14, and ASTM A1016 Section 24. Test pressure is calculated using Barlow's Formula: P = 2St/D, where allowable fiber stress S is defined as 68% of the specified minimum yield strength (SMYS) in the annealed condition (S ≈ 140 MPa / 20,400 psi for TP304L/TP316L). Coils are proof-tested up to 20.7 MPa (3,000 psi) and held for 5–10 seconds with no pressure drop or leakage observed during the hold. Finished coils also undergo 100% pneumatic underwater bubble leak testing at 0.7–1.0 MPa (100–150 psi) submerged for 15–30 seconds.
Can coil dimensions and pitch be customized to our equipment drawings?
Yes. Coil diameter, pitch, overall height, and lead ends are fabricated to your 2D drawings or 3D CAD models for compact heat exchangers and reactors.
What non-destructive and pressure testing is performed on helical coils?
Every coil undergoes NDT per standard or order (eddy current examination). Hydrostatic testing is executed per applicable ASTM standard or customer order requirements, with all inspection results recorded on the EN 10204 3.1 MTC.
Contact TeCarve