XTD manufactures seamless tube across eight alloy families, from austenitic stainless through nickel-based grades, all supplied to ASTM and ASME specifications with third-party certification. Each grade answers a defined corrosion, temperature or pressure problem, so the choice narrows fast once the service condition is known. Hot extrusion followed by cold drawing gives a weld-free wall that holds pressure without a seam to fail. Wall thickness, outer diameter and length are cut to the order, and every heat ships with mill test documentation. For pressure containment rather than tube service, the seamless pipe range carries the same grades in schedule dimensions.
How to choose a tube grade
Grade selection works from the most aggressive service condition down to documentation, and the corrosive environment carries the most weight in that decision.
The corrosive medium sets the alloy family, since chloride concentration and sour service under NACE MR0175 decide whether stainless, duplex or a nickel alloy will survive.
Operating temperature narrows it further, because elevated-temperature strength and oxidation resistance separate the austenitic grades from the nickel-based ones.
Pressure ties wall thickness and yield strength to the design condition. Standard and certification confirm the pick once the metallurgy is settled.
Higher chloride exposure pushes the choice toward a higher PREN value, and pitting risk climbs in warm seawater. The PREN corrosion calculator returns that figure for a given chemistry, and documented industry applications show how each grade behaves in real service.
Stainless steel seamless tube
The stainless steel seamless tube family covers general and elevated-temperature corrosion service, and it remains the broadest range XTD produces. It suits process lines, thermal equipment and structural duty at moderate corrosion levels.
Grade 304 and low-carbon 304L handle general oxidizing media, with 304L resisting weld-zone sensitization on thicker sections. Types 316 and 316L add 2 to 3 % molybdenum for stronger chloride pitting resistance. Stabilized grades 316Ti, 321 and 347 hold up under sustained heat without carbide precipitation at grain boundaries. For tougher duty, 310S resists furnace-temperature oxidation, 904L manages dilute sulfuric acid, and 254 SMO withstands warm chloride attack in seawater-cooled equipment.
Duplex steel seamless tube
Duplex steel seamless tube pairs high mechanical strength with chloride resistance at a lower nickel cost than austenitic grades. Its balanced ferrite-austenite microstructure roughly doubles yield strength, so wall sections run thinner for the same design pressure.
Grade S31803 delivers the original balanced duplex chemistry for oil, gas and chemical process duty. S32205 tightens the composition range, raising PREN and giving steadier pitting resistance in chloride-bearing streams.
Super duplex seamless tube
Super duplex seamless tube targets severe chloride and seawater service, where a high PREN keeps pitting and crevice corrosion in check. These grades hold strength in warm brines that break down standard duplex.
Grade S32750 combines 25 % chromium with high molybdenum and nitrogen for a PREN above 40. S32760 adds tungsten and copper for extra resistance in reducing acids and warm chlorides. Hyper-duplex S32707 pushes both strength and pitting resistance further for the harshest offshore and topside conditions.
Nickel alloy seamless tube
Nickel alloy seamless tube serves as the parent range for nickel-based grades, spanning pure nickel through specialized corrosion alloys. High nickel content lifts resistance to reducing acids, caustics and stress corrosion cracking beyond stainless limits.
Nickel 200 and low-carbon Nickel 201 resist hot caustic soda and dry halogen gases. Alloy 20, UNS N08020, handles sulfuric acid across a wide concentration band where standard stainless steel fails. High-temperature N08120 sustains oxidation and carburization resistance in furnace and process-heater service. The nickel alloy seamless tube range details each of these grades.
Inconel seamless tube
Inconel seamless tube delivers high-temperature strength with oxidation and carburization resistance. These nickel-chromium grades keep their properties where austenitic stainless steel weakens.
Alloy 600 resists chloride stress corrosion cracking and dry chlorine at elevated temperatures. Alloy 601 adds aluminum for a tighter, more adherent oxide scale under cyclic heat. Alloy 617 brings creep-rupture strength for gas-turbine and high-temperature process work. Alloy 625 pairs high strength with broad aqueous corrosion resistance, and age-hardenable 718 reaches high yield strength for demanding mechanical loads. The Inconel seamless tube range carries the full grade list.
Incoloy seamless tube
Incoloy seamless tube bridges high-temperature performance and aqueous corrosion resistance, a fit for heat exchangers and process piping under sustained thermal stress. The iron-nickel-chromium base gives useful strength at temperature without the full cost of a nickel-based alloy.
Grades 800, 800H and 800HT differ by carbon content and grain-size control, with 800H and 800HT qualified for creep service above 600°C. Alloy 825 resists sulfuric and phosphoric acids plus chloride stress corrosion cracking. Alloy 925 adds age-hardening for higher strength in sour-well completions.
Hastelloy seamless tube
Hastelloy seamless tube handles reducing acids and severe chemical service better than stainless and standard nickel grades. Its nickel-molybdenum and nickel-chromium-molybdenum chemistries resist localized and general corrosion in hot streams.
The B-series alloys B-2 and B-3 resist hydrochloric acid across all concentrations up to the boiling point. C-series grades C-4, C-22, C-276, and C-2000 tolerate mixed oxidizing and reducing media, with C-276 the long-standing benchmark for flue-gas desulfurization and aggressive chemical duty.
Monel seamless tube
Monel seamless tube suits seawater and hydrofluoric-acid service, where its nickel-copper chemistry resists fast-flowing brine and reducing acids while holding strength across a wide temperature band.
Alloy 400 resists seawater, hydrofluoric acid and neutral salts with strong ductility and good weldability. Age-hardenable K-500 adds precipitation-strengthened hardness for pump shafts, propeller sleeves and fasteners while keeping the corrosion profile of 400. The Monel seamless tube range holds both grades.
Tube types (thermal equipment)
XTD supplies seamless tube in the formats thermal equipment demands, produced without a weld seam, so there is no longitudinal join to fail under pressure or thermal cycling.
A heat exchanger tube transfers heat between two process fluids across the tube wall. Condenser tube handles cooling-water and vapor-side service in surface condensers.
A boiler tube carries steam and water under combined pressure and heat.
U-tube bends into a U profile, letting the bundle absorb thermal expansion without fixed-end stress.
Each format is available as a heat exchanger tube, condenser tube, boiler tube, and U-tube (U-bent).
ASTM / ASME standards
XTD produces to the recognised tube standard families across stainless, duplex, and nickel alloys. The ASTM standards for tube reference sets out the full grade-to-standard pairings.
Stainless steel
For stainless steel, ASTM A213 covers seamless austenitic boiler, superheater, and heat-exchanger tubes, while ASTM A269 covers general-service seamless tubes.
Duplex and super duplex
For duplex and super duplex, ASTM A789 covers seamless duplex tube and ASTM A790 covers seamless duplex pipe.
Nickel alloys
For nickel alloys, the ASTM B-series specifications cover nickel and nickel-alloy tubes.
Certifications & approvals
XTD backs its tube with third-party approvals and full documentation, including DNV, Lloyd's Register, ABS and NORSOK M-650 qualification. Each shipment carries a mill test certificate to EN 10204 3.1 or 3.2, recording chemistry, mechanical properties and heat number for full traceability. The current certifications & approvals are listed for reference.
Tools & references
Three tools speed up the specification stage before an enquiry.
The pipe & tube weight calculator estimates section weight for a given diameter and wall, which sets shipping and support loads early.
The burst-pressure calculator checks burst pressure against wall thickness for a working margin.
The pipe wall thickness calculator sizes the minimum wall to ASME B31.3 from design pressure, diameter, and allowable stress.
The pipe size chart confirms NPS and schedule dimensions against the drawing.
