Seamless Pipe and Tube FAQs from Xintongda Special Steel

Yes — XTD quotes stainless steel and duplex seamless pipe by kilogram, metric ton, meter, or foot, depending on the buyer's purchasing practice and the applicable product standard. For project comparisons, we can include theoretical weight and packing details in the same quotation.

Volume-based pricing is available and depends on alloy grade, size range, order quantity, production route, inspection scope, and delivery schedule. Final pricing is confirmed after checking current raw material cost and stock or production availability.

MOQ varies by grade, size, production route, and stock availability. Ex-stock sizes typically support smaller quantities, while custom OD/wall combinations or specialty alloys may require a higher MOQ to cover production setup and testing costs.

Trial orders are available for material qualification, supplier approval, or sample evaluation. Availability depends on current stock, size, grade, and the minimum quantity required for the relevant production or testing process.

XTD supplies both ex-stock and made-to-order stainless steel, duplex, and nickel alloy pipe. Standard sizes in common grades are often available from stock, while non-standard sizes, special lengths, or project-specific requirements are produced to order.

Yes — XTD holds inventory in frequently ordered grades and sizes to support faster delivery on urgent requirements. Because stock levels change frequently, availability should always be confirmed against the exact grade, size, wall thickness, length, and quantity needed.

When the requested material is in stock, small quantities can generally be supplied with greater flexibility than made-to-order production. Cutting, marking, repacking, and inspection requirements may still affect the final lead time.

Lead time depends on stock availability, alloy grade, size, quantity, heat treatment, NDT, third-party inspection, and documentation requirements. Stock items ship faster; custom or high-alloy orders require additional production and inspection planning time.

Yes — for project orders, XTD can plan phased shipment or JIT delivery schedules. A workable plan accounts for production batches, final inspection, surface finishing, packing, vessel schedule, and import documentation timing.

Shipments commonly move through Ningbo-Zhoushan, Shanghai, or Wenzhou. The most suitable port is selected based on cargo size, packing method, destination, freight availability, and the agreed delivery term.

Standard export packing includes bundled pipe with protective wrapping, woven bags, end caps, wooden or plywood cases, and custom seaworthy packing for longer transit. The packing method is selected according to OD, wall thickness, surface finish, quantity, and shipping route.

Standard export packing is normally included in the quotation unless stated otherwise. Special packing needs — fumigation, wooden cases, additional inner protection, lifting frames, or custom labeling — are typically quoted as line items.

Yes — XTD coordinates with freight forwarders and provides the commercial invoice, packing list, bill of lading, certificate of origin, insurance documents where applicable, and material certificates. Import customs clearance remains the buyer's responsibility under local regulations.

Door-to-door delivery can be arranged through logistics partners for suitable destinations. Final feasibility and cost depend on the destination country, delivery address, cargo dimensions, import requirements, taxes, and local handling conditions.

XTD operates a quality system covering ISO 9001, ISO 14001, and ISO 45001, alongside product or project approvals such as PED, AD 2000, ABS, DNV, LR, BV, EAC/GOST, and NORSOK M-650 where applicable. The valid scope for any certification should be confirmed against the required grade, standard, and product size.

Yes — shipments include EN 10204 3.1 Material Test Certificates as standard when required by the purchase order. Each MTC records heat number, grade, standard, size, chemical composition, mechanical properties, heat treatment condition, and applicable test results.

An EN 10204 3.1 certificate is issued by the manufacturer's inspection representative, independent of the production department. A 3.2 certificate adds validation from the purchaser's appointed inspector or an officially recognized independent inspection body, and is typically required for critical offshore, pressure equipment, power, or high-integrity projects.

Yes — third-party inspection can cover raw material review, dimensional and visual inspection, witness testing, NDT review, hydrostatic testing, marking, packing, and document review. The inspection scope should be defined in an approved ITP before production or shipment begins.

Yes — for project orders, XTD prepares or follows an approved ITP covering production route, heat treatment, dimensional checks, NDT, destructive testing, PMI, marking, packing, document review, and any hold or witness points the customer or inspector requires.

Every heat number is tracked from incoming billet or tube blank through heat treatment, hot or cold working, finishing, inspection, and final packing. Heat numbers are marked on the product and recorded on the MTC, so any finished pipe or tube can be traced back to its original melt and test results.

Positive Material Identification (PMI) is available anytime, typically using handheld XRF to verify key alloying elements such as Cr, Ni, Mo, and Cu. Elements like carbon and nitrogen require laboratory analysis rather than handheld PMI, so the required method should be specified in advance.

Available NDT methods include eddy current testing, ultrasonic testing, hydrostatic testing, and visual/dimensional inspection, selected according to product standard, size range, wall thickness, and purchase order requirements. Additional testing can be reviewed for special project specifications.

Hydrostatic testing, or an approved alternative NDT method, is performed according to the applicable ASTM/ASME, EN, or project standard. Test pressure, holding time, and acceptance criteria should be confirmed in the purchase order or ITP.

Yes — intergranular corrosion testing for austenitic stainless steel can follow ASTM A262 when required, while duplex and super duplex grades may use ASTM A923 or ASTM G48 depending on project specifications and service conditions.

Charpy V-notch impact testing is available for applicable grades, sizes, and standards used in low-temperature or cryogenic service. Test temperature, specimen orientation, acceptance value, and standard should be specified in the technical requirement.

Yes — hardness, tensile, flattening/flaring, bend, and other mechanical tests can be arranged per the product standard or customer specification. For sour service or other critical applications, hardness limits should be clearly defined in the order.

Yes — our technical team reviews operating temperature, pressure, fluid composition, chloride level, pH, sour service risk, erosion, welding requirements, and applicable standards to recommend suitable stainless steel, duplex, super duplex, or nickel alloy options.

XTD supplies seamless pipe and tube to common ASTM, ASME, EN, and project standards, including ASTM A312, A213, A269, A789, and A790, plus nickel alloy standards such as ASTM B444, B161, B163, B167, and B668 where applicable. Final compliance depends on grade, size, and specific order requirements.

Yes — dual certification is possible when the heat chemistry and mechanical properties satisfy both grades under the relevant product standard. Common examples include 304/304L and 316/316L; high-carbon grades such as 321H or 347H require separate confirmation.

Ferrite balance is controlled through chemistry, solution annealing, and rapid cooling. Verification can use metallographic point-count methods such as ASTM E562 or calibrated ferrite measurement, while ASTM A923 checks for harmful intermetallic phases in duplex stainless steels.

For suitable grades, XTD can review NACE MR0175 / ISO 15156 requirements and provide supporting tests or documentation. Compliance depends on the exact grade, hardness, heat treatment, and microstructure relative to the customer's actual service environment — it should never be assumed from grade name alone.

PREN (Pitting Resistance Equivalent Number) is commonly calculated as %Cr + 3.3 × %Mo + 16 × %N, with tungsten included in some formulas. It is a useful screening tool for chloride pitting resistance, though final material selection should also weigh temperature, pH, crevice conditions, welding, and actual service media.

Yes — XTD provides datasheets, chemical composition ranges, mechanical property requirements, standard references, dimensional data, and MTCs. For critical service, project-specific specifications and test requirements should be confirmed before order placement.

Yes — our team supports material comparison, grade selection, standard matching, size conversion, and pressure-related discussions, along with documentation review. Final engineering design and fitness-for-service decisions should still be verified by the project owner or a qualified engineering authority.

Standard tolerances follow the applicable product standard — ASTM/ASME or EN requirements for OD, wall thickness, length, straightness, and ovality. Tighter tolerances can be reviewed for heat exchanger tubes, instrumentation tubing, or customer drawings.

Yes — beyond standard ASME schedule sizes, XTD reviews customized OD, wall thickness, length, and drawing-based requirements. Feasibility depends on grade, billet size, tooling, heat treatment, production route, tolerance, and minimum order quantity.

Common finishes include solution annealed and pickled, pickled and passivated, bright annealed for suitable tube products, and mechanical polishing. Electropolishing or special Ra requirements can be reviewed for applicable tubing projects with clearly specified inner/outer surface requirements.

Yes — cut-to-length, beveling, end protection, color coding, stencil marking, barcode labels, and customer-specific marking can all be arranged. Marking content should match the purchase order, MTC, and project traceability requirements.

Yes — XTD supplies stainless steel, duplex, and nickel alloy tubes for heat exchanger, boiler, condenser, and related applications. U-bend tubes, special lengths, tighter tolerances, and additional testing can be discussed against project drawings and standards.