Steel Pipes for Boilers & Pressure Vessels

An engineering reference for buyers of boiler tube and pressure piping — water walls, superheaters and reheaters, main steam and feedwater — with the grades, creep limits, water chemistry and code certificates that keep a boiler on line for its design life.

A106 · A192 · A210
Seamless carbon-steel boiler tube
T11 / T22 / T91
A213 alloy tube · A335 P-pipe
ASME Sec. I
PG-27 wall design · B31.1 piping
To 620 °C
Superheater & main-steam duty

Code-Built Tube for the Hottest Job in the Plant

Water walls, superheaters, steam mains — one certified supply.

A boiler is a pressure vessel that lives at the edge of the material map: furnace tubes absorb radiant heat at high flux, superheater tubes carry steam at 540–620 °C where carbon steel creeps away, and main-steam piping holds 170–300 bar across a power plant’s life. Every tube is a code part — selected, tested and certified to ASME Section I / Section II and B31.1.

CREATEEL supplies the full boiler-tube and pressure-pipe package from one mill — seamless carbon steel (A192, A210, A106), chrome-moly alloy tube and pipe (A213 T-grades, A335 P-grades), stainless superheater grades and EN 10216-2 equivalents — with heat-treatment records, eddy-current testing and EN 10204 3.1 / 3.2 certification behind every heat number.

Power plant boiler and pressure piping

Boiler and pressure-piping plant: water walls, steam drums and heavy-wall mains.

Four Loads That Decide a Boiler-Tube Spec

Creep, pressure, chemistry and certification — in that order.

Four engineering loads decide every boiler-tube spec. Get any one wrong and the result is forced outage — so the rest of this page walks through how grade, wall, chemistry and documentation answer each one.

Creep

Creep & temperature

Above ~450 °C carbon steel deforms under load with time — creep. Every grade has a temperature ceiling; over-temperature events silently consume remaining life.

  • Key specifications
  • •  Carbon ceiling ~450 °C
  • •  P22 to ~575 °C
  • •  P91 to ~625 °C
Pressure

Pressure & wall

Section I’s PG-27 formula sizes wall from design pressure, OD and allowable stress at temperature — no corrosion-guess numbers, code minimums only.

  • Key specifications
  • •  t = PD/(2SE+2yP)
  • •  Allowable stress per Sec. II
  • •  Code-min wall discipline
Chemistry

Water chemistry

Dissolved oxygen pits tube internals; silica carries into steam; hardness bakes into scale. ASME feedwater limits exist to protect the tube, not just the water.

  • Key specifications
  • •  O₂ < 7 ppb
  • •  pH 8.3–10.0 (8.8–9.6 HP)
  • •  SiO₂ ≤150→1 ppm
Docs

Certification

Code parts demand full traceability: heat treatment charts, NDT of the seamless body, hydro, flattening and hardness on every lot, 3.1/3.2 MTC.

  • Key specifications
  • •  EN 10204 3.1 / 3.2
  • •  Heat-treatment charts
  • •  PMI on alloy grades

Four Duty Zones in Every Boiler

Radiant, superheat, steam mains and vessels — one supplier covers all.

From a 300 MW subcritical island to a 660 MW supercritical unit to a process-plant steam system, the same four duty zones appear — each pushing a different parameter to the front.

Four boiler duty zones

Every steam plant runs the same four tube families — this page covers all of them.

Water Walls & EconomizerFurnace radiant panels and feedwater preheat (to ~450 °C)Superheaters & ReheatersFinal steam temperature 540–620 °C, highest creep dutyMain Steam & Hot ReheatBoiler outlet to turbine — P22 / P91 heavy-wall pipingPressure Vessels & ExchangersDrums, feedwater heaters and process exchanger shells

Where each tube family fits

Click through to the detail cards below

Radiant

Water walls

Furnace radiant panels boil feedwater at high heat flux. OD 25–89 mm tube, 3–8 mm wall, membrane-bar welded into panels.

  • Key specifications
  • •  A192 / A210 Gr.A1
  • •  T11 at higher duty
  • •  OD 25–89 mm
Superheat

Superheaters & reheaters

The hottest tubes in the plant: 450–620 °C steam. Grade follows temperature — T22 through the mid sections, T91 for finals.

  • Key specifications
  • •  A213 T11 / T22 / T91
  • •  TP347H for USC finals
  • •  Creep-limited life
Steam mains

Main steam & reheat

Heavy-wall piping from boiler outlet to turbine: 170 bar subcritical on P22, 250 bar supercritical on P91.

  • Key specifications
  • •  A335 P22 / P91
  • •  OD 21.3–609.6 mm
  • •  B31.1 designed
Vessels

Vessels & exchangers

Drums, feedwater heaters and process shells — Section VIII construction on A106 / A516 plate-pipe systems.

  • Key specifications
  • •  A106 Gr.B / Gr.C
  • •  A179 exchanger tube
  • •  Section VIII rules

Grades Through the Steam Cycle

Carbon → 1.25Cr → 2.25Cr → 9Cr — follow the temperature.

The steam cycle is a temperature ladder, and the material ladder follows it rung by rung. Carbon steel carries the feedwater and evaporator duty; 1.25Cr and 2.25Cr alloys take the mid-range; the martensitic 9Cr grades own the hottest superheaters and main-steam lines. Stainless (TP304H, TP347H) appears where steam-side oxidation control matters most.

Metal temperature through the steam cycle

The grade must follow the metal temperature, zone by zone.

Economizer<400 °CA192 / A210 A1Water wall400–450 °CT11 (1.25Cr)Primary SH450–540 °CT22 (2.25Cr)Final SH540–600 °CT91 (9Cr-V)USC outlet600–620 °CT92 / TP347HMetal temperature climbs through the steam cycle — the grade must follow,from A192 carbon steel to T91/P92 martensitic alloy.

Grade selection by duty zone

ASTM A192 / A210 / A213 / A335 · stainless finals

Duty zoneMetal tempStandard grades
Economizer< 400 °CASTM A192, A210 Gr.A1
Water walls400–450 °CA192 / A210; T11 at higher flux
Primary superheater450–540 °CASTM A213 T11, T22
Final superheater540–600 °CASTM A213 T91; TP347H for USC
Ultra-supercritical600–620 °CT92, TP347H / TP310H
Main steam 540 °C / 170 barSubcriticalA335 P22
Main steam 566 °C / 250 barSupercriticalA335 P91
Main steam 600–620 °CUltra-supercriticalP92 (+ nickel alloys at peaks)

Steel Grades for Boilers & Pressure Parts

A ladder of grades, each with its own temperature ceiling.

Boiler materials are chosen by temperature, not by strength alone. A192 and A210 are the seamless workhorses inside the boiler; A106 carries the colder pressure piping around it; the A213 T-grades and A335 P-grades step up through the chrome-moly ladder as metal temperature rises. European specifications (EN 10216-2) map onto the same ladder — P265GH, 16Mo3, 13CrMo4-5.

Grade table — the boiler ladder

ASTM A106/A192/A210/A213/A335 · EN 10216-2

GradeTypeFy / Fu (MPa)Typical service
ASTM A106 Gr.BSeamless C-steel pipe240 / 415Feedwater, cold reheat, headers ≤450 °C
ASTM A106 Gr.CSeamless C-steel pipe275 / 485Higher-pressure feedwater (<300 °C)
ASTM A192Seamless C-steel tube180 / 325High-pressure water walls & economizers
ASTM A210 Gr.A1Seamless C-steel tube255 / 415Superheater & boiler tubes to ~400 °C
ASTM A210 Gr.CSeamless C-steel tube275 / 485High-stress boiler zones
ASTM A213 T111.25Cr-0.5Mo tube205 / 415Water walls, primary SH to ~550 °C
ASTM A213 T222.25Cr-1Mo tube205 / 415Superheaters & reheaters to ~575 °C
ASTM A213 T919Cr-1Mo-V tube415 / 585Final SH / RH to ~625 °C, supercritical
ASTM A335 P222.25Cr-1Mo pipe205 / 415Main steam, subcritical 540 °C / 170 bar
ASTM A335 P919Cr-1Mo-V pipe415 / 585Main steam, supercritical 566 °C / 250 bar
EN 10216-2 P265GHC-steel pressure tube265 / 410-530European pressure duty to 400 °C
EN 10216-2 13CrMo4-51.25Cr-0.5Mo280 / 440-590EU equivalent of T11 / P11

T91 / P91 quick facts

The grade that redefined main steam

  • •  9Cr-1Mo-V martensitic, normalized + tempered
  • •  ~100 MPa creep-rupture at 600 °C / 100,000 h (P22: ~60)
  • •  Thinner walls than P22 → less thermal stress
  • •  Demands strict PWHT & hardness control
  • •  Supplied with time-temperature charts

Creep & High-Temperature Life

Grade sets the ceiling; operation decides how fast you reach it.

Creep is time-dependent deformation under stress at temperature — the defining failure mode of boiler materials. Grade selection is really creep-life selection: P91 delivers roughly double the 100,000-hour rupture strength of P22 at 600 °C, which is why it became the default for supercritical main steam. But creep life is consumed by events, not just hours — every over-temperature excursion, every unqualified weld heat treatment, every oxide-driven temperature rise takes a bite the logbook never shows.

100,000-hour creep-rupture strength @ 600 °C

Why P91 replaced P22 on modern main-steam lines.

A106 Gr.B (carbon)~40 MPaP11 (1.25Cr-0.5Mo)~70 MPaP22 (2.25Cr-1Mo)~60 MPaP91 (9Cr-1Mo-V)~100 MPaApproximate 100,000-hour creep-rupture strength at 600 °C — why P91replaced P22 on modern main-steam lines.

Creep-life management

Design, monitor and document — in that order

FactorEffect on creep lifeCountermeasure
Over-temperature eventsShort excursions consume disproportionate lifeDesign for realistic peak, alarm on exceedance
Wall thinningHigher stress at constant pressureUT thickness monitoring at known wear points
Steam oxidationScale raises metal temperature9Cr grades / TP347H inlays for steam-side control
Weld joints (Type IV)Creep-weak zone in HAZ of ferritic weldsQualified PWHT, hardness survey per B31.1
Startup / shutdown cyclesThermal fatigue at heavy-wall sectionsControlled ramp rates, P91 wall-thickness care

Sizes: Boiler Tube to Main-Steam Header

19 mm superheater elements to 610 mm heavy-wall P91.

One order can span a millimetre-scale superheater element and a metre-scale main-steam header. Boiler tube runs small but thick-walled with tight tolerances; A335 pipe runs to 610 mm OD in heavy schedule walls. Seamless manufacturing dominates this page for a reason — the code prefers a pipe body without a weld seam at these pressures.

Outside-diameter coverage by product family

Boiler tube, exchanger tube and heavy-wall A335 pipe from one mill.

Boiler tube (seamless)19–127 mmHeat-exchanger tube15.9–76.2 mmAlloy pipe (A335)21.3–609.6 mmEN 10216-2 pipe19–610 mm0610 mm OD

Size & product matrix

Match product family to duty zone

ProductStandardTypical size range
Boiler tube (seamless)ASTM A192 / A210 / A213OD 19–127 mm, wall 2–14 mm
Heat-exchanger tubeASTM A179 / A213OD 15.9–76.2 mm
Water-wall panel tubeA192 / A210, membrane-weldedOD 25–89 mm, wall 3–8 mm
Alloy pressure pipeASTM A335 P5–P92OD 21.3–609.6 mm, heavy wall
Carbon pressure pipeASTM A106 Gr.B/CNPS 1/8–36″, Sch 10–160
EN pressure tubeEN 10216-2 P235GH–13CrMo4-5OD 19–610 mm

Water Chemistry: The Invisible Tube Protection

7 ppb oxygen, tight pH, controlled silica — or lose the creep margin.

Water chemistry is tube protection. A fraction of a millimetre of scale can push tube metal tens of degrees hotter — silently spending creep life and driving circumferential failures. ASME’s feedwater guidelines hold dissolved oxygen below 7 ppb at every drum pressure, keep pH in the 8.3–10.0 band (8.8–9.6 above 1000 psig), and tighten silica and hardness limits as pressure rises. The tube spec and the water spec are one system.

ASME feedwater chemistry limits

Oxygen, pH, silica and hardness — the four dials that protect the tube.

Dissolved O₂< 7 ppbAll drum pressurespH @ 25 °C8.3–10.0≤ 1000 psig drumspH @ 25 °C8.8–9.6> 1000 psig drumsSilica (SiO₂)≤ 150 → 1 ppmFalls with pressureTotal hardness≤ 0.3 ppmND above 1000 psigTotal iron (Fe)≤ 0.1 → 0.01Scales & depositsASME feedwater guidelines — oxygen attacks, silica carries over, hardness scales. Chemistry protects the tube.

Failure prevention matrix

ASME / ABMA feedwater guidance

ThreatMechanismControl
Dissolved oxygenPitting of tube internals, especially economizer inletDeaerator + scavenger; < 7 ppb at all drum pressures
Scale / hardnessInsulating deposit → local over-temperatureSoftening / RO; hardness ≤0.3 ppm, ND in high-pressure
SilicaVolatile carry-over into steam, turbine depositsBlowdown + limits that tighten from 150 to 1 ppm
Iron / copper oxidesTransport corrosion products deposit on hot wallsCondensate treatment; Fe ≤0.1→0.01 ppm
Caustic / acid gougingConcentration cells under depositspH control 8.3–10.0 (8.8–9.6 >1000 psig)

Manufacture: Structure Is the Specification

Seamless bodies, heat-treated to the code’s assumptions, tested to prove it.

Boiler tube is a heat-treatment product. Hot-finished or cold-drawn seamless bodies are annealed or normalized-and-tempered to set the grain structure the code allowable stresses assume — and for T91/P91 the tempered-martensite structure is the creep strength, so the time-temperature chart is part of the certificate. Cold drawing gives the tight OD/wall tolerances superheater elements need; every length then faces hydro, flattening, flare, hardness and eddy-current or UT testing before it ships.

Manufacture & test stack

Heat treatment sets structure; testing proves it

Process / testPurposeStandard
Hot-finished seamlessEconomical larger sizes, uniform structureA106 / A335 / EN 10216-2
Cold-drawn seamlessTight tolerance tube for elementsA192 / A210 / A213 / A179
Anneal / normalize + temperSets grain structure & allowable stressPer grade; charts on file
Hydrostatic testLeak integrity of every lengthASTM / ASME per spec
Flattening & flareDuctility & soundness of the tube bodyA192 / A210 / A213 requirements
Eddy-current / UTVolumetric NDT of the seamless bodyASTM E213 / E309 / A450
Hardness (esp. P91)Confirms correct heat treatmentA335 & B31.1 practice

Why P91 paperwork matters

The heat-treatment record is part of the material

  • •  Normalize ~1040–1080 °C + temper ~760 °C
  • •  Hardness band confirms transformation
  • •  Wrong PWHT = creep life lost before startup
  • •  We ship time-temperature charts with every lot

Welding & Post-Weld Heat Treatment

The joint must be as code-clean as the tube — especially in P91.

Boiler joints are code joints. Shop and field welding follows ASME Section IX procedures; boiler external piping follows B31.1. Carbon grades weld with E7018-class fillers; T22/P22 need matching 2.25Cr filler and PWHT; P91 is the discipline test — controlled heat input, matched 9Cr filler, mandatory post-weld heat treatment and a hardness survey to prove the joint kept its creep strength. Dissimilar joints (P91 to TP347H) get nickel filler and their own procedure.

Welding & PWHT by grade

ASME IX procedures · B31.1 fabrication

GradeFiller approachPWHT & checks
A106 / A192 / A210E7018 / ER70S-6 classPWHT per thickness; visual + hydro
T11 / P11 (1.25Cr)Matching 1.25Cr fillerPWHT typically required; hardness check
T22 / P22 (2.25Cr)Matching 2.25Cr fillerPWHT mandatory; RT/UT of joints
T91 / P91 (9Cr-V)Matching 9Cr (e.g. ER90S-B9)PWHT mandatory + hardness survey
P91 ↔ TP347HNickel filler (ENiCrFe-3)Disimilar-metal procedure, UT monitored

Type IV creep warning

The HAZ is the weak link in ferritic welds

  • •  Fine-grained HAZ creeps faster than parent metal
  • •  Service-aged P91 welds need life assessment
  • •  Hardness survey = cheapest life check
  • •  Repairs demand re-qualification, not improvisation

Design Codes & Standard Stacks

Section I for the boiler, B31.1 for the piping, EN 10216-2 for Europe.

Boiler work is code work. ASME Section I owns the boiler proper and its external piping, Section II supplies the allowable stresses behind every wall calculation, Section VIII covers the vessels, and B31.1 takes over once steam leaves the boiler envelope. European projects run the same logic on EN 10216-2 materials under the Pressure Equipment Directive. Every line of the MTC traces back into one of these books.

Common code stacks

Pick the component first, the code second

Code / standardScope
ASME BPVC Section IPower boilers — tube design (PG-27) & boiler external piping
ASME BPVC Section IIMaterial allowable stresses (SA-series)
ASME BPVC Section VIIIPressure vessels — drums, exchangers
ASME B31.1Power piping beyond the boiler proper
ASTM A106 / A192 / A210Seamless carbon-steel pipe & boiler tube
ASTM A213 / A335Alloy boiler tube (T-) & pipe (P-)
EN 10216-2European pressure tube & pipe
PED 2014/68/EUEuropean pressure equipment directive (Cat. II/III)
EN 10204 3.1 / 3.2Certification of code material

Standards flow

Product → design → protect → verify

PRODUCT•  ASTM A106 / A192•  A210 / A213 T-grades•  A335 P-gradesDESIGN•  ASME BPVC Sec. I•  PG-27 wall formula•  ASME B31.1 pipingPROTECT•  Water chemistry (ASME)•  Internal steam oxidation•  Insulation & laggingVERIFY•  Hydro + flattening•  ET / UT seamless body•  3.1 / 3.2 MTC + PMI

A Six-Step Specification Guide

From duty zone to certificate — the spec the mill needs.

1

Define the duty zone

Economizer, water wall, superheater, reheat, main steam or vessel — with realistic peak metal temperature.

2

Pick the grade ladder

A192/A210 to ~450 °C; T11/T22 mid-range; T91/P91 above 540 °C; TP347H where oxidation rules.

3

Calculate code wall

Section I PG-27: t = PD/(2SE+2yP) with Section II allowable stress at design temperature.

4

Set heat treatment

Annealed or normalized + tempered per grade; P91 demands documented time-temperature charts.

5

Plan chemistry & NDT

ASME feedwater limits protect the tube; hydro, flattening, hardness, ET/UT and PMI prove it.

6

Close the certification

EN 10204 3.1 (3.2 on request), heat-number traceability, PMI on alloys, PED where applicable.

Cr–Mo Grades: Chemistry and Temperature Ceilings

Chromium buys oxidation resistance and creep strength; molybdenum buys high-temperature strength per unit of cost. The Cr–Mo ladder below is the backbone of boiler material selection — each rung raises the metal temperature a tube can carry.

GradeNominal chemistryIndicative metal-temp ceilingWhere it lives
SA-192 / SA-210 A-1C–Mn carbon steel≈ 425 °CGenerating bank, waterwall circuits
T11 / P111.25 Cr – 0.5 Mo≈ 540 °CSuperheater mid-stages, refinery headers
T22 / P222.25 Cr – 1 Mo≈ 565 °CSuperheaters, reheaters, high-pressure headers
T91 / P919 Cr – 1 Mo – V, Nb≈ 620 °CHigh-temperature superheaters, main-steam lines

Note: The ceilings are indicative metal-temperature limits for design discussion — ASME Section II holds the stress tables that actually size the wall. The step from T22 to T91 roughly doubles creep strength, letting the same duty run either thinner wall or hotter steam.

Quality Assurance: What We Test, and Why

Every line on the MTC ties back to a clause in the spec.

Inspection

Dimensional & wall

OD & wall per grade tolerances (A450 / A530); straightness & length

  • Key specifications
  • •  ASTM A450 / A530
Inspection

Chemical analysis

Heat & product analysis: C, Mn, Cr, Mo, V per grade

  • Key specifications
  • •  ASTM A751
Inspection

Tensile & yield

Room-temperature tensile per grade (T91: 415/585 MPa)

  • Key specifications
  • •  ASTM A370 / EN ISO 6892-1
Inspection

Hardness

Brinell / Rockwell bands — the P91 heat-treatment proof

  • Key specifications
  • •  ASTM A370 / A335 practice
Inspection

Hydrostatic test

Every length pressure-tested for leaks

  • Key specifications
  • •  Per grade / ASME practice
Inspection

Flattening & flare

Ductility and soundness of the tube body

  • Key specifications
  • •  A192 / A210 / A213
Inspection

NDT of body

Eddy-current or UT volumetric examination of seamless body

  • Key specifications
  • •  ASTM E213 / E309 / A450
Inspection

MTC & marking

Heat number, grade, heat-treat lot, EN 10204 3.1 (3.2 opt.)

  • Key specifications
  • •  EN 10204 / PED 2014/68/EU

Standards & Certification Map

A complete boiler-tube specification is a stack of standards — from the material spec through design code, heat treatment, welding qualification and documentation. The five columns below are the ones our mill & engineering team reach for first; project-specific clauses (USC, PED category, TPI witness) are added on top.

Standard stack

Boiler tube

  • ASTM A192 / SA-192 — High-pressure seamless C-steel tube
  • ASTM A210 Gr.A1 / C — Medium-carbon seamless tube
  • ASTM A213 T11 / T22 / T91 — Alloy boiler & superheater tube
  • ASTM A178 — ERW C-steel boiler tube
  • ASTM A179 / A556 — Exchanger & feedwater-heater tube
Standard stack

Pressure pipe

  • ASTM A106 Gr.B / C — Seamless carbon pressure pipe
  • ASTM A335 P11 / P22 / P91 / P92 — Ferritic alloy pipe
  • ASTM A691 — Fusion-welded pressure pipe
  • EN 10216-2 — P235GH / P265GH / 16Mo3 / 13CrMo4-5
Standard stack

Design codes

  • ASME BPVC Sec. I — Power boilers, PG-27 wall design
  • ASME BPVC Sec. II — Allowable stresses (SA-series)
  • ASME BPVC Sec. VIII — Pressure vessels
  • ASME B31.1 — Power piping
  • PED 2014/68/EU — European pressure equipment
Standard stack

Heat treatment & welding

  • ASME Sec. IX — Welding procedure qualification
  • Grade PWHT rules — Normalize + temper; P91 charts
  • ASTM A988 / hardness — PWHT verification practice
  • EN ISO 15614 — European weld qualification
Standard stack

Testing & docs

  • ASTM A450 / A530 — General tube / pipe test requirements
  • ASTM E213 / E309 — UT / ET of seamless bodies
  • ASTM A370 / A751 — Mechanical & chemical test methods
  • EN 10204 3.1 / 3.2 — Mill test certificate
  • ISO 9001 — Quality system

Frequently Asked Questions

The questions we hear most often from boiler engineers, EPC procurement teams and plant owners.

What is the real temperature ceiling for carbon-steel boiler tube?

Around 450 °C continuous (short peaks to ~480 °C cost design life). Above that, creep becomes the governing mode — step up to T11/T22, then T91/P91 as metal temperature rises. The grade, not the pressure, usually sets the limit.

When should I specify T91 instead of T22?

Above ~540–575 °C metal temperature, or wherever thinner walls reduce thermal stress: T91 carries roughly double the 100,000-hour creep-rupture strength of T22 at 600 °C. It demands documented normalize-and-temper treatment and a hardness survey to deliver that strength.

How is boiler-tube wall thickness calculated?

ASME Section I PG-27: t = PD/(2SE+2yP) using the Section II allowable stress at design temperature. This is a code-minimum calculation — no ad-hoc corrosion allowances — and the design temperature must reflect realistic peaks, not nameplate steam conditions.

Why do you ship heat-treatment charts with P91?

P91’s creep strength comes from its tempered-martensite structure, which only a correct normalize (~1040–1080 °C) and temper (~760 °C) cycle produces. The time-temperature record plus hardness band is the proof the material can carry its allowable stress.

What water chemistry does my tube supplier expect me to run?

ASME feedwater guidance: dissolved oxygen < 7 ppb at all drum pressures, pH 8.3–10.0 (8.8–9.6 above 1000 psig), silica limits tightening from 150 ppm to 1 ppm as pressure rises, and no detectable hardness in high-pressure drums. Chemistry protects the tube’s creep margin.

What documentation comes with a boiler-tube delivery?

EN 10204 3.1 certificate as standard (3.2 with TPI on request), full heat-number and heat-treatment-lot traceability, hydrostatic and NDT (ET/UT) records, hardness reports on alloy grades, PMI on request, and PED certification for European code work.

What is the difference between T and P designations?

Same chemistry, different product form: “T” grades (e.g. T91 per SA-213) cover tube — the smaller hot-finished or cold-drawn form inside the boiler — while “P” grades (e.g. P91 per SA-335) cover pipe for headers and main-steam lines. A T91/P91 pair in one specification is one alloy in two geometries.

What hardness should T91 / P91 arrive at?

The normal specification window is roughly 180–250 HB, verified per heat-treatment lot. Too soft means the normalise-and-temper was off; too hard invites cracking at the welds. That is why our P91 ships with heat-treatment charts — see the quality-assurance section above.

When do I specify SA-516 plate instead of boiler-tube grades?

SA-516 (typically Gr.70) is pressure-vessel plate for drums, shell courses and formed headers — flat or shaped plate is the product form. Boiler tubes (A192/A210/A213) and pipe (A106/A335) are seamless hollow sections for the tube banks and piping. Section VIII owns the drum; Section I owns the tubes. Choose plate grades for the pressure envelope, tube grades for the heat-transfer circuits.

Do boiler tubes need impact (Charpy) testing?

Carbon and low-alloy boiler tube per A192/A210/A213 is normally supplied without Charpy unless the design minimum metal temperature demands it. Low-temperature or high-cycle duty calls out supplementary impact requirements per the spec, and alloy grades for cold-start or cyclic units often add CVN at a specified temperature to control brittle-fracture risk.

What is the difference between EN 10204 3.1 and 3.2 certification?

3.1 is the manufacturer’s declaration that the documented test results came from the supplied material; 3.2 adds a third-party (TPI) endorsement of those results for critical or regulated code work. European projects under the PED typically request 3.1 as standard and 3.2 where the notified body requires independent verification.

When should I step up from carbon-steel tube to alloy?

Stay on A192/A210 (carbon) below about 450 °C metal; above that, creep governs and you step to 1.25Cr (T11/P11), then 2.25Cr (T22/P22) as temperature climbs toward 575 °C, and to 9Cr (T91/P91) for superheaters and main-steam lines running 590–620 °C. The grade choice tracks the duty-zone temperature, not the pressure.

Why Buyers Choose CREATEEL for Boiler Tube

Grade + heat treatment + code + certification, delivered from one mill.

Mill-direct, full ladder

One contract covers A192 / A210 / A106 carbon steel, A213 T-grades, A335 P-grades and EN 10216-2 — the whole temperature ladder from one mill.

Heat-treatment discipline

Annealed and normalized-and-tempered lots with time-temperature charts on file — P91 ships with the records its creep strength depends on.

Code-ready certification

ASME Sec. I / II / VIII and B31.1 referenced on every datasheet; EN 10204 3.1 / 3.2 and PED certification for European code work.

Tested like it matters

Hydro on every length, flattening and flare, hardness bands, ET/UT of the seamless body and PMI on alloys — before shipment, not after failure.

Chemistry-aware advice

We spec against real service: ASME feedwater limits, steam-oxidation grades and over-temperature margins — not just a catalog number.

Traceable documentation

Heat-number traceability end to end, hardness and NDT records, and third-party witness available for critical heats.

Related CREATEEL Products

Every boiler project is backed by the mill’s wider steel-pipe catalogue.

Boiler Tube

Boiler Tube

Seamless boiler tube to ASTM A192 / A210 / A213 — water-wall, superheater and economizer duty.

View product details →
Seamless Pressure Pipe

Seamless Pressure Pipe

Seamless pressure pipe to ASTM A106 Gr.B and A335 — main steam, feedwater and process headers.

View product details →
Alloy Seamless Pipe

Alloy Seamless Pipe

Creep-resistant Cr-Mo grades — T11 / T22 / T91 tube and P5 / P11 / P22 / P91 pipe.

View product details →
Seamless Steel Pipe

Seamless Steel Pipe

The full seamless range — hot-finished and cold-drawn, EN 10204 3.1 / 3.2 certified.

View product details →
ERW Steel Pipe

ERW Steel Pipe

½″–24″ HFW — balance-of-plant water, air and auxiliary services.

View product details →
Butt-Weld Pipe Elbows

Butt-Weld Pipe Elbows

Butt-weld elbows and fittings to ASME B16.9 for hydronic, fire-water and power-piping circuits.

View product details →

Ready to Specify Boiler Tube?

Send us the duty zones, steam conditions and code — we will come back with a mill-direct quote, the grade-ladder proposal and the heat-treatment / certification scope behind every heat number.

📧 [email protected] | 📱 +86 15602135951 | 💬 WhatsApp Available