What is Boiler tube?
A boiler tube is a seamless pressure tube whose steel is specified for creep and oxidation at temperature and whose manufacture is controlled and witnessed for the boiler codes. Carbon grades — P235GH and P265GH (EN 10216-2), A192 and A210 A1/C (ASTM) — serve to about 400–450 °C in water-tube and fire-tube boilers, economisers, boiler banks and heat exchangers; the molybdenum and chromium-molybdenum grades — 16Mo3 (A335 P1), 13CrMo4-5 (P11 / T11), 10CrMo9-10 (P22 / T22) — take superheaters, reheaters and steam lines to 500–580 °C, and X10CrMoVNb9-1 (P91) beyond. The tube is hot-rolled or cold-drawn seamless, normalised (or normalised and tempered for the alloys), pickled or descaled, then 100 % hydrostatically tested and eddy-current or ultrasonically inspected, with the wall tolerance held to ±10 % (tighter for heat-exchanger tube) so that the boiler designer\'s minimum wall is met everywhere. Sizes follow the boiler trade: Ø 25.4–76.1 mm × 2–5 mm for tube bundles and fire tubes, Ø 88.9–168.3 mm × 4–12 mm for headers, downcomers and steam piping, in 6–12 m random or fixed lengths, plain ends. Every heat is certified EN 10204 3.1 with chemistry, tensile at room temperature, hydrotest and NDT; boiler codes (EN 12952/12953, ASME I, PED) require 3.2 witnessing by a notified body or the customer\'s inspector for pressure parts, which we arrange with TÜV, BV or Lloyd\'s at the mill. We hold the common P235GH sizes at Dilovası and source alloy and 3.2 lots from EU mills and approved Asian producers.
Seamless pipe — stocked sizes (kg/m)
Common OD × wall combinations; boiler-tube sizes Ø 25–76 mm and heavier walls are quoted per enquiry with ASME B36.10 / EN 10220 weights.
| NPS | OD (mm) | Wall (mm) | kg/m |
|---|---|---|---|
| ½" | 21.3 | 2 | 0.95 |
| ½" | 21.3 | 7.1 | 2.49 |
| ¾" | 26.9 | 2.3 | 1.4 |
| ¾" | 26.9 | 6.3 | 3.2 |
| 1" | 33.7 | 2.6 | 1.99 |
| 1" | 33.7 | 7.1 | 4.66 |
| 1¼" | 42.4 | 3.2 | 3.09 |
| 1½" | 48.3 | 3.2 | 3.56 |
| 1½" | 48.3 | 9.53 | 9.11 |
| 2" | 60.3 | 3.6 | 5.03 |
| 2" | 60.3 | 9.53 | 11.93 |
| 2½" | 76.1 | 3.6 | 6.44 |
| 3" | 88.9 | 4 | 8.38 |
| 4" | 114.3 | 4.5 | 12.19 |
| 5" | 139.7 | 5 | 16.61 |
| 12" | 323.9 | 8 | 62.32 |
| 355.6 | 8 | 68.58 | |
| 457 | 9.53 | 105.16 | |
| 610 | 9.53 | 141.12 |
EN 10216-1/2 (P235TR2, P235GH) and ASTM A106 Gr. B; other schedules on mill order.
Grades, standards and tolerances
| Grade / standard | Yield (MPa) | Note |
|---|---|---|
| P235GH (1.0345) — EN 10216-2 | 235 | carbon; boilers to ≈ 400 °C; = A192 / A210 A1 |
| P265GH (1.0425) | 265 | carbon, higher strength; = A210 C |
| 16Mo3 (1.5415) | 275 | 0.3 % Mo; superheaters to ≈ 500 °C; = A335 P1 |
| 13CrMo4-5 (1.7335) | 290 | 1 Cr 0.5 Mo; to ≈ 540 °C; = A335 P11 / A213 T11 |
| 10CrMo9-10 (1.7380) | 280 | 2.25 Cr 1 Mo; to ≈ 580 °C; = P22 / T22 |
| X10CrMoVNb9-1 (1.4903) | 450 | 9 Cr; to 620 °C; = P91 / T91, to order |
Yield at 20 °C; boiler design uses the elevated-temperature yield (Rp0.2/T) and creep values tabulated in EN 10216-2 / ASME II-D.
Which grade for which temperature
| Service | Metal temperature | EN grade | ASTM equivalent | Note |
|---|---|---|---|---|
| Fire-tube (shell) boiler tubes | ≤ 350 °C | P235GH | A192 / A210 A1 | Ø 51–76 × 3.2–4 typical |
| Water-tube boiler bank, economiser | ≤ 400 °C | P235GH / P265GH | A210 A1 / C | |
| Low-temperature superheater | 400–480 °C | 16Mo3 | A335 P1 / A209 T1 | |
| Superheater, reheater | 480–540 °C | 13CrMo4-5 | P11 / T11 | |
| High-temperature superheater, main steam | 540–580 °C | 10CrMo9-10 | P22 / T22 | |
| Supercritical / USC | 580–620 °C | X10CrMoVNb9-1 | P91 / T91 | to order; special welding |
| Heat exchangers, condensers (water side) | ≤ 300 °C | P235TR2 / P235GH | A179 / A192 | tight wall tolerance |
Design to EN 12952-3 / ASME I with the code allowable stress; the grade is fixed by the boiler designer, not the supplier.
Testing and documentation
| Test / document | Requirement | Standard |
|---|---|---|
| Chemical analysis (heat) | every heat | EN 10216-2 Table 1 / ASTM |
| Tensile at 20 °C | per lot | EN ISO 6892-1 |
| Elevated-temperature yield | on request (3.2) | EN ISO 6892-2 |
| Flattening / flaring / ring test | per lot | EN ISO 8492 / 8493 |
| Hydrostatic test | 100 % of tubes | EN 10216-2 §11.8 / A450 |
| Eddy-current or UT | 100 % (option 1 / 2) | EN ISO 10893 |
| Wall thickness | 100 % on cold-drawn tube | EN ISO 10893-12 |
| Certificate | 3.1 standard; 3.2 for code pressure parts | EN 10204 |
| PED / AD 2000 / ASME | material certification per code | notified body |
Boiler makers should state the code (EN 12952 / 12953, PED category, ASME I) on the enquiry so the right test scope is ordered at the mill.
Lengths and stock
P235GH seamless in Ø 25.4–76.1 × 2.6–4 mm and Ø 88.9–168.3 × 4–8 mm is held at Dilovası for despatch in 1–2 weeks; P265GH, 16Mo3, 13CrMo4-5, 10CrMo9-10, A192 / A210 inch sizes and all 3.2-witnessed lots are mill orders of 4–8 weeks. Lengths 6 m fixed or 5–12 m random; plain ends.
Cutting, bending, expanding and welding
Cut with a cold saw and deburr; boiler tubes are bent on mandrel or induction benders (P235GH cold to 2 × OD, alloys hot or with post-bend heat treatment per code), expanded into drums and headers with roller expanders (tube ends soft-annealed on request), and welded with matching consumables — carbon grades without preheat, 16Mo3 with 100–150 °C, Cr-Mo grades with preheat and post-weld heat treatment. Welding procedures and welder qualifications follow the boiler code.
Where it is used
- Fire-tube and water-tube steam boilers, boiler banks
- Economisers, air heaters and feedwater heaters
- Superheaters and reheaters (alloy grades)
- Heat exchangers, condensers and shell-and-tube units
- Steam lines, headers and downcomers
- Thermal-oil and hot-water boilers
Boiler tube vs seamless pipe vs ERW
Ordinary seamless pipe (P235TR / A106 B) is for pressure at ambient and moderate temperature; boiler tube adds the elevated-temperature grades, 100 % testing and code certification. ERW pipe is never used for boiler pressure parts. The plate for the drums and shells is on the P235GH and P265GH pages.
Price
Boiler tube is priced per ton or per metre by grade, size, wall and certificate level — carbon P235GH close to seamless pipe plus the testing premium, alloys well above — and follows the seamless pipe list; the bands below are indicative FOB Istanbul for the carbon and alloy ranges. 3.2 witnessing and PED certification are quoted per lot.
Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.
Export and packing
Boiler tubes ship in strapped bundles of 0.5–2 t with plastic end caps and PE wrap, on timber bearers, every tube stencilled with grade, standard, heat and size as the codes require; 18–20 t per 20', 24 t per 40' HC, 12 m tubes on flat-rack from Derince. HS 7304.31 / 7304.39 (carbon), 7304.51 / 7304.59 (alloy).
| Term | Detail |
|---|---|
| MOQ | 1 t per size (mixed sizes accepted) |
| Incoterms | FOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau |
| Lead time | Common P235GH sizes 1–2 weeks; alloy grades and 3.2 lots 4–8 weeks |
| Packing | Bundles with end caps, strapped on timber, PE-wrapped; heat and grade stencilled |
| Container / truck | 20' ≈ 18–20 t; 40' HC ≈ 24 t; 12 m tubes on flat-rack |
| Documents | Invoice, packing list, EN 10204 3.1 (3.2 on request), PED material certificate, certificate of origin |
| Payment | 30% advance, balance against B/L copy; L/C at sight above 100 t |
Certificates
Every heat carries EN 10204 3.1 with chemistry, tensile, flattening / flaring, hydrostatic and NDT results to EN 10216-2 or the ASTM standard; for code pressure parts we arrange 3.2 certificates witnessed by TÜV, BV or Lloyd\'s, PED 2014/68/EU material certification and elevated-temperature tests, and supply the mill\'s ISO 9001 / PED / AD 2000-W0 approvals.
How to order
Specify the grade and standard (e.g. P235GH EN 10216-2 TC1/TC2, A210 A1), OD × wall, length, quantity in metres or pieces, the boiler code and PED category, certificate (3.1 / 3.2 and the inspector), NDT option and delivery; a mill quotation follows within two working days.
Standards
- EN 10216-2 — seamless steel tubes for pressure purposes, elevated temperature
- ASTM A192 / A210 (carbon boiler), A335 (alloy pipe), A213 (alloy tubes)
- EN 12952 / EN 12953 water-tube and shell boilers; ASME Section I
- EN 10204 3.1 / 3.2; PED 2014/68/EU; AD 2000-W4
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: P235GH · P265GH · 16Mo3
Frequently asked questions
What is a boiler tube?
A seamless pressure tube in a grade specified for elevated temperature (P235GH, P265GH, 16Mo3, 13CrMo4-5 …), made to EN 10216-2 or ASTM A192 / A210 / A335, 100 % hydro- and NDT-tested and certified for boiler codes.
What is the difference between P235GH and P265GH tube?
P265GH has 265 MPa yield against 235 — about 13 % more allowable stress, so thinner walls or higher pressure for the same size; both are carbon grades for service to about 400 °C.
Which tube for a superheater?
16Mo3 to about 500 °C, 13CrMo4-5 (P11) to 540 °C, 10CrMo9-10 (P22) to 580 °C — fixed by the boiler designer per EN 12952 / ASME I.
Do you supply 3.2 certified boiler tube?
Yes — witnessed by TÜV, BV or Lloyd's at the mill, with PED material certification; state the code and inspector on the enquiry.
What is the ASTM equivalent of P235GH tube?
ASTM A192 (seamless carbon boiler tube for high pressure) and A210 Grade A1 are the closest; A210 C corresponds to P265GH.
What sizes are in stock?
P235GH Ø 25.4–76.1 × 2.6–4 mm and Ø 88.9–168.3 × 4–8 mm at Dilovası; other grades and sizes 4–8 weeks from the mill.