XTD manufactures seamless pipe across nine alloy families, spanning austenitic stainless, duplex, super duplex, and high-nickel grades. Each family answers a specific combination of corrosive medium, service temperature, and pressure tolerance. Every grade is shipped against a defined ASTM or ASME specification with full mill certification. Buyers must specify the product by the required grade, standard, and dimension to receive accurate material traced from heat number to the finished length. Small-bore and instrumentation requirements move to the seamless tube range rather than pipe.
How to choose a pipe grade
Grade selection runs in a fixed order. Corrosive medium carries the most weight, service temperature follows, pressure comes next, and the governing standard settles the final choice.
The corrosive medium sets the starting point, because chloride concentration and acidity decide whether an austenitic grade survives or a duplex grade becomes mandatory.
A higher chloride load demands a higher PREN value, so pitting resistance outranks every other property in the selection order.
Service temperature governs the second cut, since creep strength and oxidation resistance separate standard grades from high-nickel grades above 550 °C (1020 °F).
The pressure rating drives the third decision, matching the wall schedule against hoop and burst stress at the design temperature.
The governing standard and certification close the process, including NACE MR0175 qualification wherever sour service exposes the pipe to hydrogen sulfide.
The PREN corrosion calculator compares grades against a measured chloride load before purchase, and the industry applications reference confirms each choice against real service in oil, gas, marine, and chemical processing.
Stainless steel seamless pipe
Stainless steel serves general and elevated-temperature corrosion requirements, and it forms the broadest family in the XTD range. Process lines, heat exchangers, and structural piping under moderate chloride exposure all prefer the following grades.
The range opens with 304, 304L, and 304H for standard and high-temperature service, then extends through 309, 310, 310S, and 253MA for oxidation resistance in furnace and flue duty. The molybdenum grades 316, 316L, and 316Ti raise pitting resistance, while 321 and 347 resist sensitization through titanium and niobium stabilization. For seawater and acid handling, 904L and 254 SMO carry the family into severe chloride territory. Refer to the stainless steel seamless pipe page for complete dimensional data.
Duplex steel seamless pipe
Duplex steel pairs high strength with strong chloride resistance at a lower nickel cost than austenitic grades. The two-phase microstructure roughly doubles yield strength, which lets designers reduce wall thickness and overall weight.
XTD stocks two duplex grades that carry most of the workload: S31803 and S32205. S31803 holds the base 22-chromium composition. S32205 has increased nitrogen and chromium, which pushes the minimum PREN higher and welds cleaner in thick sections. Both handle pressure vessels, seawater piping, and chemical storage tanks, and each duplex steel seamless pipe grade ships with a full specification set on request.
Super duplex seamless pipe
Super duplex handles severe chloride and seawater exposure at the point where standard duplex reaches its pitting limit. These grades typically approach or exceed PREN 40, which resists crevice attack across warm marine and offshore service.
The super duplex seamless pipe grades range covers S32750, S32760, and S32550, and each grade balances chromium, molybdenum, and nitrogen for extreme corrosion resistance. XTD also stocks hyper-duplex S32707, which pushes PREN and strength past conventional super duplex for the most aggressive seawater duty.
Nickel alloy seamless pipe
Nickel alloy pipe answers the harshest chemical, high-temperature, and reducing environments in the catalogue. This family includes Inconel, Incoloy, Hastelloy, and Monel, and it also carries commercially pure nickel and specialized acid-resistant grades.
Nickel 200 and Nickel 201 handle caustic and chloride service, Alloy 20 resists sulfuric acid, and N08120 holds strength at high temperature. Each grade defeats a specific corrosion mechanism that standard stainless steel cannot survive. The nickel alloy seamless pipe page organizes every sub-family under one specification set.
Inconel seamless pipe
Inconel delivers high-temperature strength and oxidation resistance for gas turbines, furnaces, and reactor components. The nickel-chromium base retains mechanical properties at temperatures where stainless grades soften.
600, 601, 617, 625, and 718 are common Inconel pipe grades. Alloy 600 resists oxidizing atmospheres to about 1093 °C (2000 °F) and Alloy 601 to about 1200 °C (2200 °F); 625 adds molybdenum and niobium for fatigue and corrosion strength, and precipitation-hardened 718 reaches the highest tensile values in the group. The Inconel seamless pipe page carries the full grade specification set.
Incoloy seamless pipe
Incoloy combines high-temperature capability with aqueous corrosion resistance, which bridges stainless economy and full nickel-alloy performance. Heat exchangers, acid plants, and thermally cycled process piping all rely on the Incoloy seamless pipe page.
Incoloy grades include 800, 800H, 800HT, 825, and 925. Grades 800H and 800HT carry controlled carbon for creep strength above 600 °C (1110 °F), 825 resists sulfuric and phosphoric acid, and precipitation-hardened 925 adds strength for downhole service.
Hastelloy seamless pipe
Hastelloy seamless pipe withstands reducing acids and severe chemical service that attack most competing alloys. The molybdenum content resists both pitting and uniform corrosion across hydrochloric and sulfuric media.
The range includes B-2, B-3, C-4, C-22, C-276, and C-2000. The B-series resists hydrochloric acid at any concentration, and the C-series handles mixed oxidizing and reducing acids throughout chemical processing. The Hastelloy seamless pipe page carries the full grade specification set.
Monel seamless pipe
Monel resists seawater and hydrofluoric acid at concentrations where copper-nickel alloys fail. The high nickel-copper content stops chloride pitting and stress corrosion across marine and refinery duty.
Two of the most commonly specified grades are Monel 400 and K-500. Monel 400 serves general seawater and acid service, and precipitation-hardened Monel K-500 adds strength for pump shafts and valve components. The Monel seamless pipe page carries the full specification set.
High-nickel and super-austenitic pipe
High-nickel and super-austenitic pipe covers the most severe chloride and acid duty in the range. These grades sit above standard stainless at the point where pitting and crevice corrosion would otherwise force a full nickel alloy.
The family gathers XTD's highest-alloy grades for seawater, flue-gas desulfurization, and strong-acid handling. Each grade matches a verified corrosion limit rather than a generic claim. The high-nickel and super-austenitic pipe page lists the current grades.
Pipe types and formats
XTD produces seamless pipe exclusively, and three specialized formats sit alongside the standard grade range. Each format answers a distinct mechanical or surface requirement.
Heavy wall-thickness pipe supplies high-pressure and structural lines that need extra material for hoop strength.
High-pressure pipe meets tighter tolerance and testing regimes for critical service.
Polished pipe delivers a controlled surface finish for hygienic and architectural use.
ASTM / ASME standards
Seamless pipe follows separate specification families by alloy group. The ASTM standards for pipe page provides grade-specific detail.
Austenitic stainless steel
ASTM A312 covers seamless and welded austenitic stainless steel pipe.
Duplex and super duplex
ASTM A790 covers seamless and welded ferritic-austenitic duplex pipe.
Nickel alloy
The ASTM B-series governs nickel and nickel-alloy seamless pipe across the Inconel, Incoloy, Hastelloy, and Monel families.
Certifications and approvals
XTD holds third-party approvals from DNV, Lloyd's Register, and ABS, and manufactures to NORSOK M-650 qualification for the offshore sector. Every shipment carries a mill test certificate to EN 10204 3.1 or 3.2, which traces each length from heat number to finished pipe.
Buyers who need the full list of certifications and approvals can check the current scope before placing an order.
Tools and references
Three tools support sizing and costing before an order proceeds.
The pipe and tube weight calculator estimates line weight from grade, diameter, and wall thickness for freight and material budgets.
The burst-pressure calculator checks burst pressure against the wall schedule.
The pipe size chart confirms NPS, diameter, and schedule dimensions across the range.
