Alloy Steel Pipes, Fittings & Flanges Supplier
Overview
Sagiant Piping Industries supports enquiries for chromium-molybdenum (Cr-Mo) and creep-strength-enhanced ferritic (CSEF) alloy steel pipes, tubes, fittings, flanges and forgings for boiler, superheater, main-steam, hot-reheat and refinery high-temperature service — including A335 P1/P5/P9/P11/P12/P22/P91/P92 pipe, with the matching A213 T tubes, A234 WP fittings and A182 F forgings. Each product form is a separate specification with its own chemistry, strength, heat-treatment and acceptance rules — similar grade numbers do not make them interchangeable. Engineering bar steels, plate and bolting are supplied only where offered and are identified separately. Grade availability, condition, testing and certification are confirmed with the quotation.
Cr-Mo alloy steel grades, chemistry, standards and RFQ reference data
Conventional Cr-Mo and CSEF alloy grades by product form and delivery condition. Chemistry and mechanical values are shown with a basis label; because full current licensed standards were not available, treat them as standard/producer reference values and confirm the adopted ASTM edition, grade, class/type and product form on the material certificate.
Technical Specification
| Parameter | Specification |
|---|---|
| Product Forms | Seamless pipe, seamless tube, butt weld & forged fittings, flanges, forged/bored pipe; welded alloy pipe (A691) where offered |
| Grades | A335 P1, P5, P9, P11, P12, P22, P91, P92 (pipe); A213 T-grades (tube); A234 WP-grades (fittings); A182 F-grades (forgings). Additional Cr-Mo/CSEF grades reviewed against actual supply. |
| Size Range | Pipe from 1/2" NPS; tube by OD × wall — confirmed with quotation |
| Wall / Schedule / Class | ASME B36.10 walls (Sch 40–XXS and heavier); fittings/forgings by class; flanges B16.5 / B16.47 — separate designations, not one field |
| Standards | ASTM A335 / A213 / A234 / A182 / A369; A691 (welded); A387 (plate) where offered; ASME B16.9 / B16.5 / B16.47 / B16.11 |
| Testing & Docs | Chemistry, PMI, tensile, hardness, hydro/NDE, impact where ordered, heat-treatment charts, MTC EN 10204 3.1/3.2 — coordinated per scope |
Chemical Composition — A335 Pipe (wt %)
| Grade | C | Mn | Si | P max | S max | Cr | Mo | Other controlled elements |
|---|---|---|---|---|---|---|---|---|
| P1 | 0.10–0.20 | 0.30–0.80 | 0.10–0.50 | 0.045 | 0.045 | — | 0.44–0.65 | C-½Mo (no chromium) |
| P5 | ≤0.15 | 0.30–0.60 | ≤0.50 | 0.025 | 0.025 | 4.00–6.00 | 0.45–0.65 | 5Cr-½Mo |
| P9 | ≤0.15 | 0.30–0.60 | 0.25–1.00 | 0.025 | 0.025 | 8.00–10.00 | 0.90–1.10 | 9Cr-1Mo |
| P11 | 0.05–0.15 | 0.30–0.60 | 0.50–1.00 | 0.025 | 0.025 | 1.00–1.50 | 0.44–0.65 | 1¼Cr-½Mo |
| P12 | 0.05–0.15 | 0.30–0.61 | ≤0.50 | 0.025 | 0.025 | 0.80–1.25 | 0.44–0.65 | 1Cr-½Mo |
| P22 | 0.05–0.15 | 0.30–0.60 | ≤0.50 | 0.025 | 0.025 | 1.90–2.60 | 0.87–1.13 | 2¼Cr-1Mo |
| P91 | 0.08–0.12 | 0.30–0.60 | 0.20–0.50 | 0.020 | 0.010 | 8.00–9.50 | 0.85–1.05 | V 0.18–0.25, Nb 0.06–0.10, N 0.030–0.070, Ni ≤0.40, Al ≤0.02 |
| P92 | 0.07–0.13 | 0.30–0.60 | ≤0.50 | 0.020 | 0.010 | 8.50–9.50 | 0.30–0.60 | W 1.50–2.00, V 0.15–0.25, Nb 0.04–0.09, N 0.030–0.070, B 0.001–0.006, Ni ≤0.40, Al ≤0.02 |
Standard / producer reference chemistry — not a verified complete current-edition table. Specification ranges are limits, not "typical" chemistry; heat vs product analysis, combined/ratio limits and residual footnotes need the adopted A335 edition. P91 has two types (verify the ordered type/edition). The "P" number is not a chromium percentage and is not the ASME Section IX P-Number. Final chemistry is confirmed on the heat-wise MTC.
Grade Directory — Product Forms, UNS & Related Designations
| Grade family | Pipe / Tube / Fitting / Forging | UNS (pipe) | Related EN (comparison only) | Character & typical service |
|---|---|---|---|---|
| P1 | A335 P1 / A209 T1* / A234 WP1 / A182 F1 | K11522 | — | C-½Mo for moderate-temperature pressure parts (*C-Mo tube is A209, not A213). |
| P11 | A335 P11 / A213 T11 / A234 WP11 / A182 F11 | K11597 | 1.7335 (13CrMo4-5) | 1¼Cr-½Mo for boiler, superheater and moderate high-temperature parts. F11 has classes 1/2/3. |
| P12 | A335 P12 / A213 T12 / A234 WP12 / A182 F12 | K11562 | 1.7335 (13CrMo4-5)* | 1Cr-½Mo for elevated-temperature piping and headers. |
| P22 | A335 P22 / A213 T22 / A234 WP22 / A182 F22 | K21590 | 1.7380 (10CrMo9-10) | 2¼Cr-1Mo — the workhorse for steam lines, hydrocracker and high-pressure power service. |
| P5 | A335 P5 / A213 T5 / A234 WP5 / A182 F5 | K41545 | 1.7362 (X12CrMo5) | 5Cr-½Mo for refinery hot lines with sulphur-bearing crude. |
| P9 | A335 P9 / A213 T9 / A234 WP9 / A182 F9 | K90941 | 1.7386 (X11CrMo9-1) | 9Cr-1Mo for high-temperature oxidation and sulphidic corrosion service. |
| P91 | A335 P91 / A213 T91 / A234 WP91 / A182 F91 | K90901 | 1.4903 (X10CrMoVNb9-1) | CSEF 9Cr-1Mo-V for supercritical boilers and high-temperature steam. Verify type & edition. |
| P92 | A335 P92 / A213 T92 / A234 WP92 / A182 F92 | K92460 | 1.4901 (X10CrWMoVNb9-2) | Tungsten-modified CSEF grade for ultra-supercritical power-plant steam lines. |
EN numbers are related designations for comparison, not exact replacements — silicon, carbon, treatment, strength, class and toughness differ; substitution needs documented approval. Product forms have independent requirements (do not assume a WP or F name for every P grade). Verify each UNS against an authoritative designation reference before relying on it. Additional grades (P2, P23, P24, P36, P911, P122; tubes T23/T24) are reviewed against actual supply.
Mechanical Properties (ambient, specified minima)
| Grade (A335 pipe) | Tensile min MPa (ksi) | Yield min MPa (ksi) | Elongation | Hardness (HBW) |
|---|---|---|---|---|
| P1 | 380 (55) | 205 (30) | per specimen | — |
| P5 | 415 (60) | 205 (30) | per specimen | ≤179 |
| P9 | 415 (60) | 205 (30) | per specimen | ≤217 |
| P11 | 415 (60) | 205 (30) | per specimen | ≤163 (verify) |
| P12 | 415 (60) | 220 (32) | per specimen | ≤163 (verify) |
| P22 | 415 (60) | 205 (30) | per specimen | ≤163 (verify) |
| P91 | 585 (85) | 415 (60) | per specimen | 190–250 |
| P92 | 620 (90) | 440 (64) | per specimen | ≤250 (verify lower bound) |
Values are ambient specification minima for A335 pipe — not "annealed/solution-annealed" (inappropriate for these ferritic/martensitic grades) and not one universal figure across forms. P12 yield is 220 MPa, not the P11/P22 value; P91 hardness is a 190–250 HBW range, not a maximum alone (a max can conceal over-tempered/soft material). Tube (A213), fitting (A234) and forging (A182) minima and hardness are per their own product standard — do not apply pipe values. Elongation depends on specimen, gauge length, orientation and section. Ambient strength is not creep-rupture capability.
Heat Treatment & Microstructure
| Family | Typical delivery condition & notes |
|---|---|
| P1 (C-½Mo) | Annealed or normalized & tempered per the ordered product — confirm the permitted set in the adopted standard. |
| P5 / P9 / P11 / P12 / P22 | Normalized & tempered (or annealed/isothermal-annealed where allowed). Tempering temperature and cooling are grade- and section-dependent. |
| P91 / P92 (CSEF) | Normalized (austenitized) & tempered to a controlled tempered-martensite structure. Austenitizing/tempering windows, cooling and Ni+Mn limits are tightly controlled; hardness alone is not sufficient evidence of correct microstructure. |
Delivery heat treatment is separate from fabrication PWHT. The manufacturer's supplied condition is not the entire standard's permitted set. Treatment after forming, and repair heat treatment, apply where relevant — verify per grade, product and edition.
Physical Properties (representative)
| Property | Approximate value | Basis |
|---|---|---|
| Density | ≈ 7,850 kg/m³ (7.85 g/cm³) | general estimating assumption — varies slightly by grade |
| Young's modulus (ambient) | ≈ 200–210 GPa | room temperature reference |
| Magnetic response | Ferromagnetic | — |
| Thermal conductivity / expansion / heat capacity vs temperature | Grade- and temperature-dependent — obtain a grade-specific producer dataset | withheld: not verified per grade |
Representative reference values, not acceptance limits. For elevated-temperature design, use modulus, mean/instantaneous thermal expansion and conductivity versus temperature from a verified grade-specific source rather than a single density figure or one "maximum operating temperature". Do not interpolate across grades without a valid model.
Standards & Product Forms
| Product | Material / product specification | Separate dimensional / other basis |
|---|---|---|
| Seamless pressure pipe | ASTM A335 (P grades) | ASME B36.10; construction code & tolerances separately |
| Seamless boiler/superheater tube | A213 (T grades); A209 (T1 C-Mo) | OD × wall, min/nominal wall, length, tube tests |
| Forged/bored pipe | A369 (FP grades) | Processing, dimensions, acceptance per grade |
| Welded alloy pressure pipe | A691 (grade + class) — not A335 | Source plate spec/grade, heat treatment, radiography, pressure test |
| Butt-weld fittings | A234 (WP grades, with class where applicable) | ASME B16.9; B16.25 weld ends |
| Forged fittings & flanges | A182 (F grades; F11 Cl. 1/2/3) | B16.5 / B16.47 flanges; B16.11 forged fittings |
| Pressure-vessel plate | A387 (Gr. 5/9/11/12/22/91, with class) where offered | Thickness, treatment, examination, tolerance |
| Companion bolting | A193 B7 / B7M / B16; A320 L7 / L7M; A194 nuts (7 / 7M; Grade 4 legacy) | Diameter-dependent strength, hardness, impact, coating |
Material, dimensional, design-code and testing standards serve different purposes. Welded alloy pipe is A691, never A335. ASTM "A" and ASME "SA" are not an automatic dual-certification claim. A194 Grade 4 is a legacy nut designation — confirm a currently accepted grade and obtain approval for any legacy substitution.
Pipe Schedules, Tube Sizes & Flange Classes
| Concept | Correct treatment |
|---|---|
| Schedule | A wall-thickness designation, not a pressure rating. Required wall comes from design conditions and code calculation. |
| STD / XS / XXS | Wall designations, not universal synonyms for Sch 40 / 80 / 160. XXS is not a universal synonym for Sch 160. |
| NPS / DN | Nominal designations — not the measured ID. ID = OD − 2 × wall; published masses are theoretical. |
| B16.5 flanges | Generally NPS ½–24, Classes 150–2500 (Class 2500 through NPS 12). It is not a 36-inch flange standard. |
| B16.47 flanges | Large-diameter NPS 26–60, Series A/B — confirm class/series in the ordered edition. |
| B16.11 forged fittings | Threaded: Class 2000 / 3000 / 6000; socket-weld: Class 3000 / 6000 / 9000 (with size restrictions). |
For full dimensional data see the Pipe Schedule Chart. Tube is ordered by OD × wall, not NPS/schedule. Weight estimate: Mass (kg/m) ≈ 0.02466 × wall × (OD − wall) at 7,850 kg/m³ (nominal, mm).
Service, Temperature & Corrosion
| Topic | Guidance |
|---|---|
| Temperature & creep | Design metal temperature, code allowable stress (with edition), exposure life, creep and oxidation limits govern — not a single "maximum". P91/P92 do not have one universal service temperature; base metal and welded components differ. |
| CSEF welds (P91/P92) | Type IV creep damage in the HAZ, sensitivity to heat treatment, dissimilar-metal joints and inspection/repair planning need specific engineering — not a generic recipe. |
| High-temperature hydrogen (HTHA) | Requires a material/pressure/temperature assessment per API 941 (Nelson curves). "Cr-Mo" or P22 alone does not establish fitness. |
| Corrosion mechanisms | Distinguish oxidation, steam-side oxidation/exfoliation, sulfidation, aqueous corrosion, CUI and acid corrosion. Chromium content alone does not predict every mechanism. |
| Low-temperature | These are high-temperature grades — not automatically low-temperature qualified. Transition behaviour and code impact rules apply if cold service is intended. |
Welding & Fabrication
| Item | Guidance |
|---|---|
| Procedure & consumables | Qualified WPS/PQR and personnel; matching low-alloy consumables with low-hydrogen handling. CSEF grades need tight control of chemistry, heat input and consumable selection. |
| Preheat / interpass | Grade-, thickness- and restraint-dependent, from the applicable code and qualified procedure. Cr-Mo and especially CSEF grades typically need preheat and interpass control — a blanket "no preheat" is incorrect. |
| PWHT | Required and specified by code, grade, thickness, joint and service — with especially careful treatment for CSEF steels. Not a universal recipe and not universally waived. Record thermocouple placement, soak and cooling. |
| ASME IX | Qualifies procedures/personnel; it does not replace the construction code's design, examination, preheat/PWHT, toughness or acceptance requirements. |
| Forming / machining | Hot/cold forming may require subsequent heat treatment; control hardness, machining condition and contamination. |
Applications, Industries & Grade Guidance
| Application | Grades commonly considered | Selection information to state |
|---|---|---|
| Boiler / superheater / reheater tube | T11, T12, T22, T23/T24, T91, T92 | Temperature, allowable stress, oxidation, weldability — tube spec (A213/A209), not pipe |
| Main steam / hot reheat piping | P22, P91, P92 | Creep life, code allowables, CSEF weld control, wall/thickness |
| Refinery hot lines (sulphur / H₂) | P5, P9, P11, P22 | Sulfidation, HTHA per API 941, corrosion allowance, design temperature |
| Headers, manifolds, forgings | F11 (Cl. 1/2/3), F22, F91 | Class, section thickness, heat treatment, NDE |
| Pressure-vessel components | A387 Gr. 11/22/91 plate (where offered) | Class, thickness, toughness, design code |
Candidate specification families for enquiry — not substitutions or material-selection approvals. Exact selection is project-specific and set by the design code, not by a grade label.
Available Forms, Sizes & Dimensions
Supplied as seamless pipe and tube, butt weld and forged fittings, flanges and forgings; welded alloy pipe and plate where offered. Share grade, class/type, NPS/OD, schedule or wall, and standard for confirmation. For full dimensional data see the Pipe Schedule Chart.
| Form | Size Range | Wall / Thickness / Class | Standard |
|---|---|---|---|
| Seamless pipe | 1/2" – 24" NPS | Sch 40–XXS & heavier | ASTM A335 |
| Seamless tube | 6 – 101.6 mm OD | 1 – 12 mm wall | ASTM A213 / A209 |
| BW fittings | 1/2" – 36" | Sch / grade-class | ASME B16.9 / A234 |
| Forged fittings | 1/8" – 4" | Class 2000–9000 (threaded / SW) | ASME B16.11 / A182 |
| Flanges | 1/2" – 24" (B16.5); 26"+ (B16.47) | Class 150–2500 (per series) | ASME B16.5 / B16.47 / A182 |
Dimensional coverage is standard-based; the confirmed supply range is stated with the quotation. Schedule, wall designation, fitting class and flange class are separate concepts. B16.5 covers ½–24"; larger flanges use B16.47 Series A/B.
Frequently Asked Questions
What is the difference between A335 P, A213 T, A234 WP and A182 F grades?
They are the same alloy family in different product forms — pipe, tube, butt-weld fitting and forging respectively — each governed by its own specification with independent chemistry, strength, heat-treatment and acceptance requirements. A similar number does not make them interchangeable.
How do P91 and P92 differ?
Both are creep-strength-enhanced ferritic (CSEF) 9Cr grades, but P92 is tungsten-modified with different V/Nb/N/B controls and higher strength. Their alloy design and fabrication controls differ — one is not an automatic substitute for the other.
Is a P91 hardness below a maximum sufficient?
No. P91 has a specified hardness range (about 190–250 HBW); a maximum alone can conceal over-tempered or soft material. The specified range, correct heat treatment and tempered-martensite microstructure all matter — product hardness is not automatically weld/HAZ acceptance.
Is PWHT always required for Cr-Mo welds?
It is set by the construction code, grade, thickness, joint and qualified procedure — with especially careful control for CSEF (P91/P92) steels. It is neither a universal recipe nor universally waived.
Product Range
The alloy steel range can be supplied with related pipes, tubes, butt weld fittings, forged fittings, flanges and forgings where required by the BOQ, with welded pipe and plate where offered.
Applications
For dimensional references, see the Pipe Schedule & Fittings Guide. For related supply, review Pipes & Tubes, Butt Weld Fittings, Forged Fittings and Flanges. For carbon-steel bolting and general pipe, see Carbon Steel.
Types of Products
| Type | Description |
|---|---|
| Pipes & Tubes | Seamless A335 pipe and A213/A209 tube |
| Fittings | A234 WP butt weld and A182 F forged fittings |
| Flanges | A182 F forged flanges and machined items |
| Plate / Bar / Forgings | A387 plate and forgings, subject to grade and project availability |
Available Forms
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Frequently Asked Questions
What is the difference between A335 P, A213 T, A234 WP and A182 F grades?
They are the same Cr-Mo alloy family in different product forms — seamless pipe (A335 P), seamless tube (A213 T), butt-weld fitting (A234 WP) and forging (A182 F). Each is a separate specification with its own chemistry, strength, heat-treatment and acceptance requirements; a matching number does not make them interchangeable.
How do P11 and P22 differ?
P11 is 1¼Cr-½Mo and P22 is 2¼Cr-1Mo — P22 has higher chromium and molybdenum for greater oxidation resistance and elevated-temperature strength. Compare verified chemistry and the design-code allowable stress for the actual service; neither has a single universal temperature limit.
How do P91 and P92 differ?
Both are creep-strength-enhanced ferritic (CSEF) 9Cr grades. P92 is tungsten-modified with different V/Nb/N/B controls and higher strength. Their alloy design and fabrication controls differ, so one is not an automatic substitute for the other.
What do forging/fitting classes and Grade 91 types mean?
Forged-fitting classes (e.g. B16.11 threaded 2000/3000/6000, socket-weld 3000/6000/9000) and A182 forging classes describe pressure/strength ratings for those components, and Grade 91 has material types with different chemistry. These are separate from flange pressure classes (B16.5/B16.47) — do not mix them.
Is a P91 hardness below a maximum sufficient?
No. P91 has a specified hardness range (about 190–250 HBW). A maximum alone can conceal over-tempered or soft material. The specified range, correct normalizing-and-tempering and the resulting tempered-martensite microstructure all matter; product hardness is not automatically weld/HAZ acceptance.
Are ASTM and EN alloy grades equivalent?
Treat EN/DIN numbers as related designations for comparison, not exact replacements. Chemistry, heat treatment, size-dependent strength, class and toughness can differ. Substitution requires a documented comparison and purchaser or design approval.
Is PWHT always required for Cr-Mo welds?
It is set by the construction code, grade, thickness, joint and qualified procedure — with especially careful control for CSEF (P91/P92) steels. It is neither a universal recipe nor universally waived, and delivery heat treatment is separate from fabrication PWHT.
Is Schedule 80 a pressure rating?
No. It is a wall-thickness designation associated with pipe size. Required wall and allowable pressure come from the material, temperature, dimensions, tolerances, corrosion allowance and the governing design-code calculation.
Can PMI confirm the complete grade?
Not on its own. PMI identifies alloying elements but has method and element limits (for example carbon and nitrogen), so it cannot fully certify a CSEF grade by itself. Rely on the material test certificate and the specified chemistry, mechanical and heat-treatment tests.
What should an alloy-steel RFQ include?
State the standard and edition, product form, grade with class/type, manufacturing route, delivery condition, dimensions, quantity, service (temperature/pressure/medium), supplementary tests, inspection document and destination. Availability and inspection scope are confirmed with the quotation.
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