Super Duplex 2507 Tubing (UNS S32750)
Super Duplex 2507 tubing is OD-sized, round instrumentation tube drawn from super-duplex stainless steel S32750 (UNS S32750, EN / W.Nr. 1.4410), a nominal 25Cr-7Ni-4Mo-N grade with a roughly 50/50 ferrite-austenite microstructure and a Pitting Resistance Equivalent Number above 42. It carries process fluid or gas between components and seats into a compression fitting's ferrule set to make a leak-tight, make-and-break joint. Crestflo supplies 2507 tube seamless and welded to ASTM A789, in both imperial and metric sizes, shipped in the solution-annealed condition so it bends and cones cleanly into a ferrule. You reach for 2507 tube when a line runs warm chlorides, seawater, brine, or sour (H₂S) fluid and the run also has to carry pressure at the lightest possible wall, the service where 316 stainless pits and stress-corrosion-cracks and where even standard Duplex 2205 is under-alloyed. Standard items ship from stock; specials are built to order, with delivery running 6-8 weeks. Request a quote to price your run.
SAF™ 2507 is a trademark of Alleima (formerly Sandvik); Zeron® 100 is a trademark of Rolled Alloys. Swagelok® and Parker® are trademarks of their respective owners; Crestflo is not affiliated, and interchange is dimensional.
Why Specify Super Duplex 2507 Tubing
Tube is the long, continuous wetted surface of an instrument hookup. Unlike a fitting or a valve, it has no dead legs or packing bores, but it has length, every inch of it exposed to the media, and it has to survive the cold work of bending and ferrule make-up without cracking. On a seawater or chloride line that rules out a lot of materials. A stainless tube that pits or stress-corrosion cracks midway along a run is as dead as one that fails at the fitting.
Super Duplex 2507 is a nitrogen-enhanced super-duplex stainless steel, and its two-phase austenite-plus-ferrite structure is what makes it the right tube for warm chloride service. Two properties drive the choice. First, corrosion: with a PREN above 42, 2507 resists chloride pitting and crevice corrosion well beyond 316L (≈24) and standard Duplex 2205 (≈35), and its duplex structure gives it strong resistance to chloride stress-corrosion cracking, the failure mode that limits austenitic stainless in seawater and hot brine. Second, strength: the grade's minimum yield is roughly double that of annealed 316/316L, and on a tube that is a direct, bankable advantage. A thinner wall holds the same pressure, so a 2507 run weighs less and costs less metal than a 316 run of the same rating, which is exactly what matters on weight-critical umbilicals, hydraulic control lines, and compact offshore and subsea bundles.
There is one limit to respect. Super Duplex 2507 is not a high-temperature grade. Continuous service is generally capped at about 600 °F (316 °C); above that range, sigma-phase and 475 °C embrittlement degrade the grade's toughness and corrosion resistance. Where a line runs hot, an austenitic nickel alloy such as Inconel 625 or Hastelloy C-276 is the pick, not 2507. Keep 2507 in the warm-chloride, seawater, and sour-service window where it excels.
The full metallurgical picture, composition ranges, mechanical and physical properties, PREN, and corrosion-by-media data, lives on the Super Duplex 2507 alloy grade page. This page stays on the tube: how it's made, sized, finished, tested, and matched to the fitting.
Also Specified As: Alloy 2507 Tube, SD2507 Seamless Tubing, UNS S32750 Tube
Buyers and specifiers call this tube several ways, and each one points to the same 25Cr super-duplex stainless. A requisition might read "Alloy 2507 tubing," "2507 super duplex seamless tube," "S32750 instrument tube," "SD2507 hydraulic tubing," or "duplex 2507 tube," and every one of them lands here. The formal designations are UNS S32750 and EN / Werkstoff 1.4410 (EN steel name X2CrNiMoN25-7-4). SAF™ 2507 is Alleima's (formerly Sandvik's) trade name for the same S32750 grade, referenced here for identification only. Zeron® 100 (UNS S32760) is a closely related 25Cr super-duplex grade specified for the same seawater and warm-chloride duty, but it is a distinct UNS number, not an exact equivalent of S32750. The welded form is often written "welded-and-drawn tube," the seamless form "cold-drawn seamless tube."
Scope: this is round, OD-sized instrumentation and fluid-system tube for compression and tube-fitting connections. It is not oilfield coiled tubing for downhole well intervention, not structural or ornamental tube, and not pipe specified by nominal pipe size (NPS) and schedule. Crestflo supplies 2507 in instrumentation tube, fitting, and valve forms only, not mill bar, sheet, plate, or pipe.
Seamless vs Welded Super Duplex 2507 Tubing
Both constructions accept a compression fitting the same way, and for duplex tube both fall under a single product-form specification, ASTM A789, which covers seamless and welded ferritic-austenitic (duplex) stainless tubing for general service. That is one of the ways duplex tube differs from austenitic stainless and the nickel alloys, which split across separate seamless and welded standards. Seamless 2507 tube is cold-drawn from a hollow with no longitudinal weld, which makes it the default where you want maximum integrity for higher-pressure, cyclic, or critical seawater and sour service. Welded-and-drawn 2507 tube is formed from strip, seam-welded, then cold-drawn to size; it is dimensionally consistent and cost-effective for general instrument and fluid-system work. On a duplex, the weld and the following solution anneal and quench have to restore the ferrite-austenite balance across the seam and heat-affected zone, which is why the annealing and the ferrite check below matter as much as the chemistry.
| Attribute | Seamless 2507 tube | Welded-and-drawn 2507 tube |
|---|---|---|
| Product-form standard | ASTM A789 (ASME SA-789) | ASTM A789 (ASME SA-789) |
| Method | Cold-drawn from a hollow, no seam | Strip formed, seam-welded, cold-drawn |
| Typical use | Higher-pressure, cyclic, critical seawater & sour service | General instrument and fluid-system service |
| Condition | Solution-annealed & quenched | Solution-annealed & quenched |
Not sure which construction to call out? The deep dives on seamless tubing and welded tubing walk through the trade-off before you commit a spec.
Super Duplex 2507 Tube Attributes at a Glance
| Attribute | Value (per applicable standard; customizable to requirement) |
|---|---|
| Alloy | Super Duplex 2507 / Alloy 2507 / SD2507 (UNS S32750, EN 1.4410, X2CrNiMoN25-7-4) |
| Family | 25Cr-7Ni-4Mo-N super-duplex (ferritic-austenitic) stainless steel |
| Construction | Seamless and welded-and-drawn, both to ASTM A789 (ASME SA-789) |
| Common OD | 1/8″, 1/4″, 3/8″, 1/2″, 5/8″, 3/4″, 1″ and 6, 8, 10, 12 mm; 1/16″ (3 mm) small-bore and larger to 2″ (50 mm) to order |
| Common wall | 0.028″–0.083″ for instrument service, to the OD and wall tolerances of ASTM A789 |
| Units | Imperial and metric |
| Condition / temper | Solution-annealed and quenched for bending, ferrule seating, and ferrite balance; also the NACE MR0175-accepted condition |
| Strength (annealed, typical min) | 0.2% yield ≥ 550 MPa (80 ksi), about 2× annealed 316; tensile ≥ 795 MPa (116 ksi); elongation ≥ 15% |
| Hardness (max) | ≤ 32 HRC (≈ 310 HBW), the NACE MR0175 sour-service ceiling |
| PREN (Cr + 3.3×Mo + 16×N) | > 42 (typically ≈ 42.5 min) |
| Max continuous service temperature | ≈ 600 °F (316 °C), not a high-temperature grade |
| Form | Straight lengths; continuous coils for long runs and umbilicals |
| Finish | Mill/bright-annealed; pickled; passivation; electropolish (EP); oxygen/UHP cleaning on request |
| Working pressure | A function of OD × wall × allowable stress per ASME B31.3, stated per size, no blanket rating |
| Testing | Hydrostatic or nondestructive (eddy-current) electric test per spec; ferrite check; PMI; dimensional |
| Traceability | Heat/lot number on every part; EN 10204 MTC 3.1 standard, 3.2 on request; PMI |
| Sour service | UNS S32750 suitable per NACE MR0175 / ISO 15156, hardness controlled ≤ 32 HRC |
| Origin | Indian origin; US / European melt available on request, with full traceability |
Super Duplex 2507 Tube Sizes: OD, Wall & Imperial/Metric
Instrument tube is specified by its actual outside diameter and wall thickness, given in both imperial and metric units, never by NPS and schedule. The common instrument range runs fractional 1/8″ to 1″ and metric 6 to 12 mm; smaller 1/16″ (3 mm) small-bore tube and larger diameters up to 2″ (50 mm) are available to order. Wall thickness is chosen to carry the pressure and to suit the ferrule, and both OD and wall are held to the tolerances of ASTM A789. This is where 2507's strength pays off directly: because the grade's allowable stress is well above austenitic stainless, a given pressure can be carried on a thinner wall, so the designer can trade some of the wall back for weight and cost on a long run. Working pressure is not a single blanket figure, though; it is calculated from OD, wall thickness, and the alloy's allowable stress per ASME B31.3, so it is stated per size and wall rather than as one rating for the grade.
| Imperial OD | Nearest metric OD | Common walls |
|---|---|---|
| 1/8″ | 3 mm | 0.028″, 0.035″ |
| 1/4″ | 6 mm | 0.028″, 0.035″, 0.049″ |
| 3/8″ | 10 mm | 0.035″, 0.049″, 0.065″ |
| 1/2″ | 12 mm | 0.035″, 0.049″, 0.065″, 0.083″ |
| 3/4″ | 18 mm | 0.049″, 0.065″, 0.083″ |
| 1″ | 25 mm | 0.065″, 0.083″ |
Values per applicable standard; customizable to requirement. For how to work back from a target pressure to a wall thickness, see the tube sizing and wall thickness guide, and for the full dimensional matrix across the range, the tubing size chart.
Temper & Ferrite Balance: Solution-Annealed for Bending and Ferrule Seating
The single most important mechanical property of instrument tube is not its peak strength but its workability. 2507 tube ships in the solution-annealed and quenched condition, and on a duplex that condition does three jobs at once. First, it is what lets the tube bend around a radius and cone down under a ferrule without cracking, so the joint seats and seals the way a compression fitting is designed to. Second, it sets the ferrite-austenite phase balance near the target 50/50: a correct solution anneal followed by a rapid quench dissolves intermetallic phases and fixes the right ratio, and if the quench is too slow or the anneal off-temperature, the tube can carry excess ferrite or sigma phase that costs it toughness and corrosion resistance. Third, the solution-annealed condition is the one NACE MR0175 / ISO 15156 works from for sour service, with hardness held to the ≤ 32 HRC ceiling. In that condition 2507 still carries high strength, a 0.2% yield around 80 ksi (550 MPa), roughly twice annealed 316, with a tensile minimum near 116 ksi (795 MPa) and elongation at or above 15%. Because the phase balance is load-bearing on a duplex, every lot gets a ferrite check (see testing, below). Specify the hardness or condition to your own standard on the RFQ and it is confirmed on the certificate.
Finishes & Cleanliness: Bright-Anneal, Pickle, Electropolish & Oxygen-Clean
Super Duplex 2507 tube ships in a mill/bright-annealed or pickled finish as standard. For high-purity gas, analytical, and oxygen service, passivation, electropolishing (EP), and oxygen/UHP cleaning with capped-and-bagged packaging are available. Electropolishing lowers surface roughness and smooths the inner diameter, which matters where particle generation, moisture dry-down, or deposit build-up is the concern; on a chloride line a clean, smooth surface also removes the crevices and embedded iron where pitting likes to start. Standard UHP electropolish surface-roughness targets can be specified right on the RFQ to your own standard; electropolished tubing and oxygen and UHP cleaning cover the options in detail. Finish and cleanliness figures follow the applicable standard and are customizable to requirement.
Super Duplex 2507 Tube Standards: ASTM A789, A790, NORSOK & ASME B31.3
2507 tube is covered by the duplex stainless tube specification, not the austenitic-stainless or nickel-alloy ones: both seamless and welded tube fall under ASTM A789, with its matching ASME boiler-code SA-789 designation. The companion pipe specification, ASTM A790, covers S32750 pipe, which is outside Crestflo's instrumentation tube scope and is noted only for reference. Allowable working pressure for a given size and wall is calculated per ASME B31.3. For offshore work, the NORSOK M630 material data sheets and the related NORSOK M650 manufacturing-qualification standard apply, and for sour service the material is offered to NACE MR0175 / ISO 15156. Crestflo holds the standard approvals that apply to instrumentation tube and is ISO 9001 / 14001 / 45001 and PED certified.
| Standard | Scope | Applies here |
|---|---|---|
| ASTM A789 / ASME SA-789 | Seamless & welded duplex (incl. S32750) tubing, general service | Seamless & welded 2507 tube |
| ASTM A790 / ASME SA-790 | Seamless & welded duplex (S32750) pipe | Reference only, pipe is out of scope |
| NORSOK M630 / M650 | Offshore material data sheet & manufacturing qualification | Offshore 2507 tube |
| ASME B31.3 | Process-piping allowable pressure | Wall / working-pressure calculation |
| NACE MR0175 / ISO 15156 | Sour-service material requirements (≤ 32 HRC) | Sour-service tube |
| EN 10204 MTC 3.1 / 3.2 | Material test certification | Every order |
| ISO 9001 / 14001 / 45001 & PED | Quality, environmental, safety, pressure | Certified |
Working Pressure: Calculated per ASME B31.3, Not Assumed
There is no single pressure rating for "2507 tube," and any supplier who quotes one is skipping the engineering. Allowable internal pressure depends on three things: the tube OD, its wall thickness, and the alloy's allowable stress at the service temperature. ASME B31.3 sets the method, relating wall thickness to pressure, diameter, the allowable stress value S, the weld-joint quality factor E, and the coefficient Y. Seamless tube carries a higher joint factor than welded, which is part of why seamless is chosen for higher-pressure work. Super Duplex 2507's edge in this calculation is its high allowable stress, roughly twice that of austenitic 316 near room temperature, which is what lets a thinner wall carry the same pressure. That advantage holds up to the grade's service ceiling; above about 600 °F (316 °C) the material is off the table on toughness grounds, not just on allowable stress. Give us the OD, wall, temperature, and medium on the RFQ and the engineering team returns the calculated working pressure for your configuration. Values per the applicable standard; customizable to requirement.
Testing, Ferrite Check, NDT & NACE MR0175 Sour-Service Compliance
Every length of 2507 tube is verified before it ships. ASTM A789 requires each tube to pass either a hydrostatic test or a nondestructive (eddy-current) electric test, and dimensional checks confirm OD, wall, and straightness against the ordered tolerances. Because this is a duplex, the ferrite-austenite phase balance is checked as well, by metallographic point count or magnetic measurement, to confirm the microstructure sits in the specified band rather than running ferrite-heavy or carrying intermetallic phase from an off-anneal. Positive material identification (PMI) confirms the alloy on the material, which matters for a super-duplex where chemistry controls the phase balance and the corrosion performance. NDT is done in-house; destructive testing, where a job calls for it, goes to ISO/IEC 17025-accredited labs, and third-party inspection is available on request.
For sour service, 2507 tube material is offered to NACE MR0175 / ISO 15156, with hardness controlled to the ≤ 32 HRC ceiling the standard sets for the grade. Confirm the hardness and the environmental limits, H₂S partial pressure, temperature, and chloride content, in the standard against your application, and note the sour-service requirement on the RFQ.
| Check | What it proves | Basis |
|---|---|---|
| Hydrostatic or eddy-current test | Pressure integrity / freedom from defects | ASTM A789 |
| Ferrite / phase-balance check | Ferrite-austenite ratio in the specified band, no intermetallic phase | Duplex microstructure control |
| Dimensional inspection | OD, wall, length, straightness to tolerance | ASTM A789 |
| PMI | Alloy is genuinely S32750 | Every part |
| Material certification | Heat chemistry & mechanicals | EN 10204 MTC 3.1 / 3.2 |
Straight Lengths & Coiled Super Duplex 2507 Tube
2507 tube ships as straight lengths for racked and rigidly supported runs, and as continuous coils for long analyzer and sample lines, chemical-injection cores, and hydraulic and umbilical bundles where a joint-free run is the whole point. On an offshore umbilical the 2507 coil earns its keep twice over: it keeps the count of mechanical joints down, which on a seawater or buried line is one fewer place to leak, and its high strength lets the core run thinner-walled, which trims weight across a long bundle. Both forms are supplied solution-annealed and quenched; call out length or coil length on the RFQ. For long-run applications, see coiled tubing; for thicker-wall high-pressure control lines, hydraulic tubing.
Material Traceability & Certification
Every length of Super Duplex 2507 tube carries its own heat/lot number, and each order ships with an EN 10204 MTC 3.1 certificate as standard, 3.2 available on request. PMI confirms the grade at the part level, every time, and the ferrite check backs it with the microstructure data a duplex job needs. That documentation supports the audit trails that offshore, subsea, and sour-service work demand, the kind of job where a mis-specified or off-balance tube in a long run is an expensive thing to discover in commissioning. Full detail is on the traceability page.
Applications for Super Duplex 2507 Tubing
2507 tube earns its place wherever warm chlorides, seawater, and wet H₂S defeat 316 and standard 2205, and the run also needs to carry pressure at the lightest practical wall:
- Offshore topside & subsea oil & gas, platform and subsea instrument, hydraulic, and chemical-injection lines in chloride and H₂S service, where chloride-SCC immunity and high strength both count. See the offshore & subsea industry page.
- Seawater injection, lift & cooling, seawater and produced-water systems where pitting and crevice resistance decide service life.
- Desalination & RO, high-chloride brine instrument and sample lines on seawater desalination plant.
- Weight-critical umbilicals & hydraulic control lines, long coiled cores where the thinner high-strength wall trims bundle weight and a corrosion failure mid-run is unrecoverable.
- Marine & shipboard systems, high-chloride instrument and sample lines.
- Petrochemical, chemical & FGD, chloride-bearing process, sampling, and flue-gas desulfurization instrument lines. See petrochemical and chemical processing.
Where the chloride duty is milder and cost matters more, step down to Duplex 2205 tube; the full trade-off is in 2205 vs 2507. Where the line runs hot, step up to an austenitic nickel alloy such as 625 or C-276, which 2507 cannot match above its 600 °F ceiling.
Pairing 2507 Tube With 2507 Fittings and Valves
A tube is one part of the hookup, and the joint is only as corrosion-resistant as its weakest metal. For a matched instrument run, pair this tube with Super Duplex 2507 tube fittings and Super Duplex 2507 instrumentation valves so the whole assembly, tube, ferrules, and valve body, carries the same PREN, the same strength, and the same traceability. Crestflo supplies the tube alongside compression fittings tested to ASTM F1387, so the ferrule set seats correctly on the exact OD and wall you ordered, and the joint is a dimensional match rather than a mix of two suppliers' tolerances. Putting a 2507 tube into a 316 fitting just moves the failure point to the ferrule.
Drop-In Interchange and the Tube-Plus-Fitting System
Crestflo 2507 tube is cut and finished to standard OD and wall, so it drops into the compression fittings you already run, and the matching 2507 fittings are built as dimensional interchange / equivalent parts for the major brands, with the fitting ends qualified to ASTM F1387. These are not "compatible" or "intermix" parts. Swagelok® and Parker® remain trademarks of their respective owners, and Crestflo is not affiliated; the interchange is strictly dimensional. Moving a run off a major brand? Request your Swagelok®/Parker® cross-reference and the engineering team maps your tube and fitting part numbers to Crestflo 2507 equivalents. We don't publish a part-number table.
Origin & US-Serving Positioning
Crestflo manufactures for the US market. Standard product is of Indian origin; US or European melt is available on request, with full material traceability. Tube is engineered as a US drop-in and ships in 6-8 weeks, well under the 20+ weeks typical of the majors. If a project calls for a specific melt origin or TAA/DFARS handling, specify it on the RFQ and we'll address it straight, no hedging. See the US-origin compliance page for how we document it.
Why Crestflo for Super Duplex 2507 Tubing
Crestflo operates as the instrumentation division of an export house with four decades behind it and formal recognition from the Government of India, with a proven Middle-East delivery record. That backing grounds a focused instrumentation brand built on a handful of clear advantages:
- Lead time of 6-8 weeks versus 20+ weeks typical of the majors, on standard stock and made-to-order specials alike.
- A matched system, tube plus F1387-tested fittings and ferrules that seat on the exact OD and wall you ordered.
- Both seamless and welded 2507 tube to ASTM A789, in both imperial and metric, straight or coiled.
- Heat-number marking plus MTC 3.1/3.2 on every order, PMI-confirmed and ferrite-checked, so a super-duplex is never taken on trust.
- NACE MR0175 / ISO 15156 material options for sour service, hardness controlled ≤ 32 HRC, with NORSOK M630/M650 for offshore work.
- ISO 9001 / 14001 / 45001 & PED certified, cost-competitive after US duties and tariffs, with small MOQs and private-label available.
We Engineer Confidence.
Request a Quote for Super Duplex 2507 Tubing
Give us the details: seamless or welded, OD and wall, straight length or coil, finish and cleanliness, and the line conditions (media, pressure, temperature, sour-service requirement). We'll calculate the working pressure, confirm the spec, and schedule the run.
- Request a quote, the fastest path to pricing and lead time.
- Request a sample for qualification.
- Request your Swagelok®/Parker® cross-reference and we'll map your tube and fitting part numbers.
Datasheets and CAD are available to customers on request. Reach Crestflo's US sales desk at sales@crestflousa.com or +1 346 594 9005 (Houston, TX). Round out the system with 2507 tube fittings and 2507 valves, browse the tubing pillar for other grades and constructions, and see where this tube serves in offshore and subsea.
Frequently Asked Questions
What is Super Duplex 2507 tubing?
It's OD-sized, round instrumentation and fluid-system tube drawn from super-duplex stainless S32750 (UNS S32750, EN 1.4410), a 25Cr-7Ni-4Mo-N grade with a roughly 50/50 ferrite-austenite structure and a PREN above 42. Crestflo supplies it seamless and welded to ASTM A789, solution-annealed and quenched so it bends and seats into a compression fitting. It's specified for warm chlorides, seawater, brine, and sour (H₂S) service, where 316 stainless pits or stress-corrosion cracks and standard Duplex 2205 is under-alloyed.
Is Crestflo 2507 tubing seamless or welded?
Both. Seamless 2507 tube is cold-drawn with no weld seam and is the default for higher-pressure, cyclic, or critical seawater and sour service. Welded-and-drawn tube is formed from strip, seam-welded, and cold-drawn, and is cost-effective for general instrument work. For duplex tube, both constructions fall under one product-form specification, ASTM A789. The weld and the following solution anneal and quench restore the ferrite-austenite balance across the seam, and both forms take a compression fitting the same way.
What standards does Super Duplex 2507 instrumentation tubing meet?
Seamless and welded 2507 tube both follow ASTM A789 (ASME SA-789); the companion pipe specification A790 is out of Crestflo's tube scope. Allowable working pressure is calculated per ASME B31.3, offshore work follows NORSOK M630/M650, sour-service material is offered to NACE MR0175 / ISO 15156 with hardness ≤ 32 HRC, and material certification follows EN 10204 (3.1 standard, 3.2 on request). Crestflo manufactures under an ISO 9001 / 14001 / 45001 and PED certified system.
What sizes and wall thicknesses are available in 2507 tube?
The common instrument range runs fractional 1/8″ to 1″ and metric 6 to 12 mm, in walls from about 0.028″ to 0.083″, to the tolerances of ASTM A789. Smaller 1/16″ (3 mm) small-bore tube and larger diameters up to 2″ (50 mm) are available to order. Because 2507's allowable stress is well above austenitic stainless, a given pressure can often be carried on a thinner wall. Values are per the applicable standard and customizable to requirement.
What is the working pressure of 2507 tubing?
There's no single rating. Allowable pressure is calculated from the tube OD, wall thickness, and the alloy's allowable stress at temperature per ASME B31.3, so it's stated per size and wall, not as one figure for the grade. 2507's high strength, roughly twice the allowable stress of 316 near room temperature, lets a thinner wall carry the same pressure, up to the grade's 600 °F (316 °C) ceiling. Give us the OD, wall, temperature, and medium and we return the calculated pressure.
Why is 2507 tube high strength, and what does that get me?
Super Duplex 2507 has a minimum 0.2% yield around 80 ksi (550 MPa), roughly double annealed 316/316L, a property of its balanced duplex microstructure. On a tube that means a thinner wall can carry the same pressure, so a 2507 run weighs less and uses less metal than a 316 run of the same rating. That matters most on weight-critical umbilicals, hydraulic control lines, and compact offshore and subsea bundles.
What is the maximum service temperature of 2507 tubing?
Continuous service is generally limited to about 600 °F (316 °C). Above that range, sigma-phase and 475 °C embrittlement degrade the grade's toughness and corrosion resistance, so 2507 is not a high-temperature grade. For hot service, step up to an austenitic nickel alloy such as Inconel 625 or Hastelloy C-276, which hold strength and corrosion resistance well above 2507's ceiling.
Why specify 2507 tube over Duplex 2205 or 316?
2507 is the step up from 316 and 2205 when the chloride duty gets severe. With a PREN above 42 it resists pitting and crevice corrosion well beyond 316L (≈24) and standard Duplex 2205 (≈35), and its duplex structure resists chloride stress-corrosion cracking far better than austenitic 316. Its yield is about twice that of 316, so walls can be thinner. For milder chloride service, 2205 may be enough at lower cost; see 2205 vs 2507 to compare. Where the line runs hot or turns to strong reducing acid, a nickel alloy is the call.
Is the tube supplied annealed for bending and fitting make-up?
Yes. 2507 tube ships in the solution-annealed and quenched condition, which gives it the ductility to bend around a radius and cone cleanly under a ferrule, and which also sets the ferrite-austenite phase balance near the target 50/50. That same condition is the one NACE MR0175 / ISO 15156 works from for sour service, with hardness held to ≤ 32 HRC. You can specify the condition or hardness to your own standard on the RFQ.
Is a ferrite check done on 2507 tube?
Yes. On a duplex the ferrite-austenite phase balance is load-bearing for both toughness and corrosion resistance, so every lot is checked, by metallographic point count or magnetic measurement, to confirm the microstructure sits in the specified band rather than running ferrite-heavy or carrying intermetallic phase from an off-anneal. It's reported alongside the PMI and the chemistry on the material certificate.
Is 2507 tubing suitable for sour (NACE MR0175) service?
Yes. Super Duplex 2507 (UNS S32750) is offered to NACE MR0175 / ISO 15156 for sour (H₂S-containing) service, with hardness controlled to the ≤ 32 HRC ceiling the standard sets. Crestflo supplies the tube with full traceability; confirm the hardness and the environmental limits, H₂S partial pressure, temperature, and chloride content, in the standard against your application and note the requirement on the RFQ.
What finishes and cleaning are available for 2507 tube?
2507 tube ships mill/bright-annealed or pickled as standard. Passivation, electropolishing (EP), and oxygen/UHP cleaning with capped-and-bagged packaging are available for high-purity gas, analytical, and oxygen service. On a chloride line a clean, smooth, passivated surface also removes the crevices and embedded iron where pitting starts. Electropolish surface-roughness targets can be specified on the RFQ to your own standard.
Can I get the tube and matching fittings from one source?
Yes. Crestflo supplies 2507 tube together with dimensionally matched compression tube fittings and ferrules tested to ASTM F1387, so the ferrule set seats correctly on the exact tube OD and wall you ordered. It's one drop-in system rather than a mix of two suppliers' tolerances, and the whole joint carries the same corrosion resistance and strength.
Does 2507 tube come in straight lengths or coils?
Both. Straight lengths suit racked, rigidly supported runs; continuous coils suit long analyzer and sample lines, chemical-injection cores, and hydraulic and umbilical bundles where a joint-free run reduces leak paths. 2507's high strength lets a coiled core run thinner-walled, trimming bundle weight. Both forms ship solution-annealed and quenched; specify length or coil length on the RFQ.
What testing and certification come with the tube?
Each tube passes a hydrostatic or nondestructive (eddy-current) electric test per ASTM A789, plus a ferrite / phase-balance check and dimensional inspection of OD, wall, and straightness. PMI confirms the alloy, and every length carries a heat/lot number with an EN 10204 MTC 3.1 certificate (3.2 on request). NDT is in-house; destructive testing goes to ISO/IEC 17025-accredited labs, and third-party inspection is available on request.
Is Crestflo 2507 tubing made in the USA?
Crestflo manufactures for the US market. Standard product is of Indian origin, with US or European melt available on request and full material traceability. Tube is engineered for a US drop-in fit and ships in 6-8 weeks. Specify any TAA/DFARS or melt-origin requirement on the RFQ.
What is the lead time and minimum order for 2507 tube?
Standard items ship from ready stock; specials are made to order, with a 6-8 week US-serving delivery. Small minimum order quantities apply, and private-label and made-to-print runs are available.
Related Pages
- Super Duplex 2507 alloy grade & corrosion data
- Super Duplex 2507 tube fittings · Super Duplex 2507 instrumentation valves
- Tubing pillar · Seamless tubing · Welded tubing · Alloy tubing
- Duplex 2205 · 2205 vs 2507
- ASTM A789 · ASME B31.3 · NACE MR0175 · EN 10204 MTC
- Offshore & subsea instrumentation · petrochemical & chemical