Delivering High Quality Stainless Steel and Alloy Piping Products — Pipes, Tubes, Fittings, Flanges and more for Global Industries.
sales@savoypipinginc.com
Delivering High Quality Stainless Steel and Alloy Piping Products — Pipes, Tubes, Fittings, Flanges and more for Global Industries.
sales@savoypipinginc.com
| Choose | When | Watch-outs |
|---|---|---|
| P9 | High-Cr chrome-moly heater / process | Not CSEF like P91 |
| P5 | Lower Cr sulfidation package | Different allowable stresses |
| P91 | CSEF creep-critical steam | Strict welding/PWHT |
ASTM A335 / ASME SA335 P9 seamless NPS: ____ Sch/wall: ____ Qty: ____ HT: N&T IBR: Y/N MTC: 3.1/3.2 Destination: ____
Email sales@savoypipinginc.com with destination and any IBR / NACE / TPI notes.
Savoy Piping Inc. supplies ASTM A335 P9 / ASME SA335 Grade P9 seamless chrome moly pipe — the 9Cr-1Mo grade used when heater and process piping needs stronger high-temperature corrosion and sulfidation resistance than 5Cr material can reliably give.
P9 is not a “generic alloy pipe.” It is a deliberate chemistry choice: higher chromium for scale and sulfur resistance, with molybdenum for elevated-temperature strength. Procurement teams typically pair it with matching fittings and flanges (WP9 / F9) and ask for clear heat treatment and hardness records before release.
Where P9 fits: severe refinery heater circuits, high-temperature transfer lines, and process piping exposed to sulfur-bearing streams at elevated metal temperatures. If the duty is milder, P5 may be enough. If the system is a power-plant steam header rather than a refinery heater, designers more often specify P11, P22, or creep-strength grades P91 / P92.
We offer P9 hot-finished and cold-drawn seamless pipe to ASTM A335 / ASME SA335, with EN 10204 3.1 / 3.2 certificates, optional IBR documentation, and third-party inspection (SGS, TUV, Lloyd’s, etc.) when projects require it.
Also see: Alloy steel seamless hub · Chrome moly hub · Alloy buttweld.
| A335 P9 Alloy Steel Seamless Pipes Specification | ASTM A335 / ASME SA335 |
| A335 P9 Alloy Steel Seamless Pipes Grades | ASTM A335 / ASME SA335 Grade P9 (9Cr-1Mo) |
| A335 P9 Alloy Steel Seamless Pipes Type | Seamless - Hot Rolled / Cold Drawn |
| A335 P9 Alloy Steel Seamless Pipes Outer Diameter Size | A335 - 3/8" NB to 30" NB (Nominal Bore Size) |
| A335 P9 Alloy Steel Seamless Pipes Wall Thickness | Schedule 20 to Schedule XXS (Heavier On Request) Up to 250 mm Thickness |
| A335 P9 Alloy Steel Seamless Pipes Length | 5 to 7 Meters, 09 to 13 Meters, Single Random Length, Double Random Length And Customize Size. |
| A335 P9 Alloy Steel Seamless Pipes Ends | Plain Ends / Beveled Ends / Coupling |
| A335 P9 Alloy Steel Seamless Pipes Delivery Conditions | As Rolled, Cold Drawn, Normalizing Rolled, Thermomechanical Rolled / Formed, Normalizing Formed, Normalized and Tempered / Quenched and Tempered - BR / N / Q /T |
| A335 P9 Alloy Steel Seamless Pipes Coating | Epoxy Coating / Colour Paint Coating / 3LPE Coating. |
| A335 P9 Alloy Steel Seamless Pipes Other Testing | Tensile Test, Transverse Tension Tests, Flattening Test, Metal Structure and Etching Tests, Photomicrographs, Hardness Tests, etc. |
| A335 P9 Alloy Steel Seamless Pipes Dimension | All Pipes Is Manufactured and Inspected / Tested to the Relevant Standards including ASTM, ASME, API. |
| A335 P9 Alloy Steel Seamless Pipes Value Added Services | Draw / Expansion / Machining / Sand Blasting / Shot Blasting / Galavanizing / Heat Treatment |
| A335 P9 Alloy Steel Seamless Pipes Packaging | Loose / Bundle / Wooden Pallet / Wooden box-a / Plastic Cloth Wraps / Plastic End Caps / Beveled Protector |
| A335 P9 Alloy Steel Seamless Pipes Shipment & Transportation | By Road - Truck / Train, By Sea - Break-bulk Conventional Vessel / FCL (Full Container Load) / LCL (Less Container Load) / 20 Feet Container / 40 Feet Container / 4 Feet Container / High Cube Container / Open Top Container, By Air - Freighter Civil Passenger and Cargo Planes |
| A335 P9 Alloy Steel Seamless Pipes Material Test Certificate | Manufacturer Test Certificate As Per EN10204 3.1, 3.2 / Laboratory Test Certificate From NABL Approved Lab. / Under Third Party Inspection Agency Like SGS, TUV, DNV, LLOYDS, ABS ETC |
ASTM A335 / ASME SA335 Grade P9 is seamless ferritic alloy-steel pipe for high-temperature service, commonly described as 9Cr-1Mo. Higher chromium content improves resistance to oxidation and high-temperature sulfidation compared with P5, while molybdenum supports strength at temperature.
Like other A335 grades, P9 pipe must be suitable for bending, flanging, and fusion welding. Welding and PWHT practice matter: chromium-molybdenum steels need controlled preheat, interpass, and post-weld heat treatment to keep hardness and toughness in a safe window for high-temperature service.
Buyers often compare P9 with P5 (lower Cr, still common in heaters) and with modern 9Cr creep grades P91 / P92. Those CSEF grades are optimized for supercritical steam creep strength; classic P9 remains a process/refinery chrome moly choice rather than a USC main-steam substitute.
Use P9 when process corrosion (especially sulfidation) drives material selection and 9% chromium is justified. Use P5 for many standard heater duties where 5Cr is adequate. Use P91/P92 when the design is driven by creep strength in high-pressure steam systems, not by classic refinery heater sulfidation. Matching tube product for heat-exchange service is typically ASTM A213 T9.
Heat-analysis composition limits for seamless pipe ordered as Grade P9 (UNS S50400). Values below are mass percent; confirm against the ASTM A335 / ASME SA-335 edition on the purchase order.
| Element | Composition, % |
|---|---|
| Carbon, max | 0.15 |
| Manganese | 0.30–0.60 |
| Phosphorus, max | 0.025 |
| Sulfur, max | 0.025 |
| Silicon | 0.25–1.00 |
| Chromium | 8.00–10.00 |
| Molybdenum | 0.90–1.10 |
| Seamless | |
| P-9 | |
| Tensile Strength, min., psi | |
| ksi | 60 |
| MPa | 415 |
| Yield Strength, min., psi | |
| ksi | 30 |
| MPa | 205 |
| Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test | ||
| For material heat treated in a batch-type furnace, tests shall be made on 5% of the pipe from each treated lot. for small lots, at least one pipe shall be tested. | ||
| For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5% of the lot, but in no case less than 2 pipe. | ||
| Notes for Hardness Test: | P91 shall not have a hardness not exceeding 250 HB/265 HV [25HRC]. | |
| Notes for Bend Test: | For pipe whose diameter exceeds NPS 25 and whose diameter to wall thickness ratio is 7.0 or less shall be subjected to the bend test instead of the flattening test. | |
| Other pipe whose diameter equals or exceeds NPS 10 may be given the bend test in place of the flattening test subject to the approval of the purchaser. | ||
| The bend test specimens shall be bent at room temperature through 180 without cracking on the outside of the bent portion. | ||
| The inside diameter of the bend shall be 1 inch [25 mm]. | ||
| Hydrostatic test | Each length of pipe shall be Hydro tested, at option of manufacture, nondestructive electric testing can be used. | |
| P5, P9, P11, and P22 | |||
| Grade | Heat Treatment Type | Normalizing Temperature Range F [C] | Subcritical Annealing or Tempering Temperature Range F [C] |
| P9 | Full or Isothermal Anneal | ||
| Normalize and Temper | ***** | 1250 [675] |
| NPS [DN] Designator | Tolerance, % from Specified | |||
| Over | Under | |||
| 1/8 to 2 1/2 [6 to 65] incl., all t/D ratios | 20.0% | 12.5% | ||
| Above 2 1/2 [65], t/D or = 5% | 22.5% | 12.5% | ||
| Above 2 1/2 [65], t/D 5% | 15.0% | 12.5% | ||
| (t = Specified Wall Thickness; D = Specified Outside Diameter) | ||||
| Calculated Minimum Elongation Values | |||||
| Elongation in 2 in. or 50 mm, min % | |||||
| Wall Thickness | P5, P9, P11, P22 | P91 | |||
| in. | mm | Longitudinal | Transverse | Longitudinal | |
| 5/16 (0.312) | 8 | 30 | 20 | 20 | |
| 9/32 (0.281) | 7.2 | 28 | 19 | 19 | |
| 1/4 (0.250) | 6.4 | 27 | 18 | 18 | |
| 7/32 (0.219) | 5.6 | 26 | 17 | ||
| 3/16 (0.188) | 4.8 | 24 | 16 | ||
| 5/32 (0.156) | 4 | 22 | 15 | ||
| 7/8 (0.125) | 3.2 | 21 | 14 | ||
| 3/32 (0.094) | 2.4 | 20 | 13 | ||
| 1/18 (0.062) | 1.6 | 18 | 12 | ||
Outside Diameter at any point shall not vary from standard specified more than:
| NPS [DN] Designator | Over | Under | ||
| in. | mm | in. | mm | |
| 1/8 to 1 1/2 [6 to 40], incl. | 1/64 (0.015) | 0.40 | 1/64 (0.015) | 0.40 |
| Over 1 1/2 to 4 [40 to 100], incl. | 1/32 (0.031) | 0.79 | 1/32 (0.031) | 0.79 |
| Over 4 to 8 [100 to 200], incl. | 1/16 (0.062) | 1.59 | 1/32 (0.031) | 0.79 |
| Over 8 to 12 [200 to 300], incl. | 3/32 (0.093) | 2.38 | 1/32 (0.031) | 0.79 |
| Over 12 [300] | +/- 1% of the specified outside diameter | |||
(On Tags attached to each Bundle in case of Bundled Pipe) Markings will adhere to prescribed specifications in A 999/A999M and be: Rolled, Stamped, or Stenciled (Mfrs. Option)
| In addition, markings will include: | ||
| Length of pipe | ||
| Marking to indicante the test method(s) | |||
| Hydrostatic | Nondestructive | Marking | |
| YES | NO | Test Pressure | |
| NO | YES | NDE | |
| NO | NO | NH | |
| YES | YES | Test Pressure/NDE | |
Orders for material under this specification should include the following, as required, to describe the desired material adequately:
| Quantity | Feet, meters, or number of lengths |
| Name of material | Seamless Alloy Steel Pipe |
| Grade | P5, P9, P11, P22, P91 |
| Manufacturer | Hot-finished or cold-drawn |
| Size using one of the following: | |
| NPS and Schedule Number | |
| Outside Diameter and Nominal Wall Thickness | |
| Outside Diameter and Minimum Wall Thickness | |
| Inside Diameter and Nominal Wall Thickness | |
| Inside Diameter and Minimum Wall Thickness | |
| Length | Specific or Random |
| End Finish | |
ASTM A335 P9 (9Cr-1Mo) seamless pipe is used in high-temperature refinery and petrochemical piping where higher chromium is needed for oxidation and sulfidation resistance, including severe heater and transfer-line service.
P5 (5Cr-0.5Mo) is widely used for many heater and hot process lines. P9 (9Cr-1Mo) is selected when corrosion/sulfidation risk is higher and the design calls for more chromium. Confirm with the project corrosion engineer or piping class; do not substitute grades only on price.
No. Both are roughly 9% chromium alloys, but P91 is a vanadium-niobium modified creep-strength-enhanced ferritic steel for supercritical power piping. Classic P9 is the traditional 9Cr-1Mo process grade. Chemistry, heat treatment, welding, and allowable stresses differ.
Yes. Savoy Piping Inc. supplies ASTM A335 / ASME SA335 P9 seamless pipe with EN 10204 3.1 or 3.2 MTCs, and can arrange IBR Form III-C and third-party inspection when specified.
We supply this product for domestic and export projects with MTC (EN 10204 3.1 standard; 3.2 / TPI on request). Include destination, Incoterms and inspection needs on the RFQ.