ASTM A234 WP9 pipe fittings are chromium and molybdenum alloyed steel pipe fittings that offer durable service in high-pressure pipe applications requiring moderate and elevated temperatures. The pipe fittings are available in seamless and welded constructions and conform to ASTM A234 and other standards like ASME B16.9, B16.28, and MSS SP standards. These are made from 9Cr-1Mo alloys which offer improved strength and anti-oxidation properties. They are available in a variety of designs including elbows, tees, reducers, caps, and stub ends, allowing efficient fluid movement and connections within pipes. They come in several sizes and thicknesses, offering many choices for use in many applications. At Metinox Overseas, you can buy premium quality ASTM A234 WP9 pipe fittings in standard or custom sizes.
Request a Quote now!Table of Contents
- Specification of ASTM A234 WP9 Pipe Fittings
- Chemical Composition of Grade WP9 Alloy Steel Butt Weld Fittings
- Mechanical Properties of ASTM A234 Alloy Steel WP9 Butt Weld Pipe Fittings
- WP9 vs WP91: 9Cr-1Mo vs 9Cr-1Mo-V — Which Grade?
- ASTM A234 WP9 Equivalent Grades
- Types of ASTM A234 WP9 Pipe Fittings
- Pressure Rating Chart of ASTM A234 WP9 Pipe Fittings
- Weight Chart of ASTM A234 WP9 Pipe Fittings
- ASTM A234 WP9 Pipe Fittings Dimension Chart
- Heat Treatment & PWHT for ASTM A234 WP9 Fittings
- Application Uses of ASTM A234 WP9 Pipe Fittings
- Price List of ASTM A234 WP9 Pipe Fittings
- Related Products
- Frequently Asked Questions
Specification of ASTM A234 WP9 Pipe Fittings
| Property | Specification Details |
|---|---|
| Specifications | ASTM A234 / ASME SA234 |
| Dimensions | ASME/ANSI B16.9 |
| Size | 1/8" NB TO 48" NB. (Seamless & 100% X-Ray Welded, Fabricated) |
| Type | Seamless / Welded / Fabricated |
| Bending Radius | R=1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom |
| Thickness | Sch 5s, Sch 10s, Sch 40s, Sch 80s, Sch 160s, Sch XXS or Custom Thickness upto 50 MM |
| Classes | Class 1 and Class 3 (per ASTM A234) |
| Manufacturing Practices | Fine grain — mandatory for WP9 |
| NDE Of Welds | Required after forming per ASTM A234 |
| Hardness | 217 HBW max |
Chemical Composition of Grade WP9 Alloy Steel Butt Weld Fittings
| Element | Min % | Max % |
|---|---|---|
| Carbon (C) | — | 0.15 |
| Manganese (Mn) | 0.30 | 0.60 |
| Silicon (Si) | 0.25 | 1.00 |
| Sulphur (S) | — | 0.030 |
| Phosphorus (P) | — | 0.030 |
| Chromium (Cr) | 8.00 | 10.00 |
| Molybdenum (Mo) | 0.90 | 1.10 |
Mechanical Properties of ASTM A234 Alloy Steel WP9 Butt Weld Pipe Fittings
| Class | Tensile range | Yield min | Elongation min | Hardness max |
|---|---|---|---|---|
| WP9 Class 1 | 415–585 MPa (60–85 ksi) | 205 MPa (30 ksi) | 30% | 217 HBW |
| WP9 Class 3 | 520–690 MPa (75–100 ksi) | 310 MPa (45 ksi) | 20% | 217 HBW |
WP9 vs WP91: 9Cr-1Mo vs 9Cr-1Mo-V — Which Grade?
| Property | WP9 (9Cr-1Mo) | WP91 (9Cr-1Mo-V-Nb) |
|---|---|---|
| Chemistry | 9Cr-1Mo, no V or Nb | 9Cr-1Mo + V 0.18–0.25%, Nb 0.06–0.10%, N 0.030–0.070% |
| Tensile (Class 1 / Type 1) | 415–585 MPa | 585–760 MPa |
| Yield (min) | 205 MPa (30 ksi) | 415 MPa (60 ksi) |
| Allowable stress at 600°C | Lower | ~50–70% higher |
| PWHT requirement | 730–790°C (mandatory) | 730–790°C (mandatory; strictly controlled) |
| Wall thickness vs WP9 | Baseline (WP9) | Up to ~40% thinner for same pressure |
| Fine-grain requirement | Yes — mandatory | Yes — mandatory |
| NDE of welds | Required | Required |
| Typical application | Moderate duty 9Cr service, refinery heaters | Critical HP/HT steam, ultra-supercritical boilers |
ASTM A234 WP9 Equivalent Grades
| Standard System | Grade / Designation | Notes |
|---|---|---|
| ASTM / ASME | A234 WP9 / SA234 WP9 | Buttweld pipe fittings — this spec |
| ASTM — Pipe | A335 P9 | Same 9Cr-1Mo; seamless alloy steel pipe |
| ASTM — Forged | A182 F9 | Same 9Cr-1Mo; forged fittings and flanges |
| DIN / EN Werkstoff | 1.7386 | European equivalent material number |
| EN Grade | X12CrMo9-1 | European equivalent grade designation |
| JIS | STPA26 | Japanese equivalent seamless alloy pipe |
Types of ASTM A234 WP9 Pipe Fittings
90° Elbow
45° Elbow
Equal Tee
Reducing Tee
Concentric Reducer
Eccentric Reducer
Pipe Cap
Pipe Bend
Stub End
Pressure Rating Chart of ASTM A234 WP9 Pipe Fittings
| Nominal Diameter IN / mm |
Outside Diameter IN / mm |
Nominal Wall Thickness Gauge | IN | mm |
Pipe & Reducers psi / kPa |
L.R. Elbows psi / kPa |
Mitred Elbows (L.R.) psi / kPa |
Tees psi / kPa |
Laterals psi / kPa |
|---|---|---|---|---|---|---|---|
| 4 / 100 | 4.500 / 114 | 14 | 0.078 | 2.0 | 505 / 3480 | 450 / 3105 | 380 / 2620 | 250 / 1725 | 155 / 1070 |
| 5S | 0.083 | 2.1 | 535 / 3690 | 485 / 3345 | 405 / 2790 | 265 / 1825 | 165 / 1140 | ||
| 12 | 0.109 | 2.8 | 710 / 4895 | 640 / 4415 | 535 / 3690 | 355 / 2450 | 220 / 1515 | ||
| 10S | 0.120 | 3.0 | 790 / 5445 | 710 / 4895 | 595 / 4105 | 390 / 2690 | 245 / 1690 | ||
| 11 | 0.125 | 3.2 | 825 / 5690 | 740 / 5100 | 620 / 4275 | 410 / 2825 | 255 / 1760 | ||
| 5 / 125 | 5.563 / 141 | 14 | 0.078 | 2.0 | 405 / 2790 | 365 / 2515 | 305 / 2105 | 200 / 1380 | 125 / 860 |
| 5S | 0.109 | 2.8 | 570 / 3930 | 515 / 3550 | 425 / 2930 | 285 / 1965 | 175 / 1205 | ||
| 11 | 0.125 | 3.2 | 660 / 4550 | 595 / 4105 | 490 / 3380 | 325 / 2240 | 200 / 1380 | ||
| 10S | 0.134 | 3.4 | 710 / 4895 | 640 / 4415 | 530 / 3655 | 350 / 2415 | 215 / 1480 | ||
| 6 / 150 | 6.625 / 168 | 14 | 0.078 | 2.0 | 340 / 2345 | 305 / 2105 | 260 / 1795 | 168 / 1160 | 105 / 725 |
| 5S | 0.109 | 2.8 | 475 / 3275 | 430 / 2965 | 365 / 2515 | 235 / 1620 | 145 / 1000 | ||
| 11 | 0.125 | 3.2 | 550 / 3790 | 495 / 3415 | 420 / 2895 | 275 / 1895 | 170 / 1170 | ||
| 10S | 0.134 | 3.4 | 590 / 4070 | 530 / 3655 | 450 / 3105 | 295 / 2035 | 180 / 1240 | ||
| 8 / 200 | 8.625 / 219 | 14 | 0.078 | 2.0 | 260 / 1795 | 230 / 1585 | 200 / 1380 | 125 / 860 | 80 / 550 |
| 5S | 0.109 | 2.8 | 365 / 2515 | 325 / 2240 | 280 / 1930 | 180 / 1240 | 110 / 760 | ||
| 11 | 0.125 | 3.2 | 420 / 2895 | 375 / 2585 | 320 / 2205 | 210 / 1450 | 130 / 895 | ||
| 10S | 0.134 | 3.4 | 450 / 3105 | 405 / 2790 | 345 / 2380 | 225 / 1550 | 140 / 965 | ||
| 10 / 250 | 10.750 / 273 | 12 | 0.109 | 2.8 | 290 / 2000 | 260 / 1795 | 225 / 1550 | 140 / 965 | 90 / 620 |
| 11 | 0.125 | 3.2 | 335 / 2310 | 300 / 2070 | 260 / 1795 | 160 / 1105 | 105 / 725 | ||
| 5S | 0.134 | 3.4 | 360 / 2480 | 320 / 2205 | 275 / 1895 | 170 / 1170 | 110 / 760 | ||
| 10S | 0.165 | 4.2 | 445 / 3070 | 400 / 2760 | 340 / 2345 | 215 / 1480 | 135 / 930 | ||
| 12 / 300 | 12.750 / 324 | 12 | 0.109 | 2.8 | 245 / 1690 | 220 / 1515 | 190 / 1310 | 115 / 795 | 75 / 515 |
| 11 | 0.125 | 3.2 | 280 / 1930 | 250 / 1725 | 220 / 1515 | 130 / 895 | 85 / 585 | ||
| 5S | 0.156 | 4.0 | 350 / 2413 | 315 / 2170 | 275 / 1895 | 165 / 1140 | 110 / 760 | ||
| 10S | 0.180 | 4.6 | 405 / 2790 | 365 / 2515 | 315 / 2345 | 195 / 1345 | 125 / 860 |
Weight Chart of ASTM A234 WP9 Pipe Fittings
| DN | Sch 10S: Con Reducer | Sch 10S: Ecc Reducer | Sch 10S: Reducing Tee | Sch 40S: Con Reducer | Sch 40S: Ecc Reducer | Sch 40S: Reducing Tee | Sch 80S: Con Reducer | Sch 80S: Ecc Reducer | Sch 80S: Reducing Tee |
|---|---|---|---|---|---|---|---|---|---|
| 40x25 | 0.19 | 0.19 | 0.60 | 0.26 | 0.26 | 0.76 | 0.34 | 0.34 | 0.90 |
| 50x25 | 0.28 | 0.28 | 0.73 | 0.40 | 0.40 | 1.10 | 0.54 | 0.54 | 1.37 |
| 50x40 | 0.31 | 0.31 | 0.76 | 0.45 | 0.45 | 1.15 | 0.59 | 0.59 | 1.43 |
| 80x50 | 0.55 | 0.55 | 1.56 | 1.00 | 1.00 | 2.91 | 1.79 | 1.79 | 3.91 |
| 100x50 | 0.78 | 0.78 | 2.94 | 1.50 | 1.50 | 4.48 | 1.95 | 1.95 | 6.55 |
| 100x80 | 0.87 | 0.87 | 3.04 | 1.74 | 1.74 | 4.64 | 2.33 | 2.33 | 6.79 |
| 150x80 | 1.82 | 1.82 | 6.86 | 3.95 | 3.95 | 9.68 | 5.51 | 5.51 | 11.57 |
| 150x100 | 1.96 | 1.96 | 7.10 | 4.07 | 4.07 | 11.94 | 5.96 | 5.96 | 11.97 |
| 200x100 | 3.01 | 3.01 | 13.46 | 6.55 | 6.55 | 17.98 | 9.23 | 9.23 | 24.18 |
| 200x150 | 3.19 | 3.19 | 14.08 | 6.74 | 6.74 | 18.82 | 10.12 | 10.12 | 25.31 |
ASTM A234 WP9 Pipe Fittings Dimension Chart
| DN | Sch 10S: 90° Elbow | Sch 10S: 45° Elbow | Sch 10S: Equal Tee | Sch 40S: 90° Elbow | Sch 40S: 45° Elbow | Sch 40S: Equal Tee | Sch 80S: 90° Elbow | Sch 80S: 45° Elbow | Sch 80S: Equal Tee |
|---|---|---|---|---|---|---|---|---|---|
| 8 | 0.02 | 0.01 | 0.03 | 0.03 | 0.02 | 0.06 | 0.04 | 0.03 | 0.07 |
| 10 | 0.03 | 0.02 | 0.05 | 0.03 | 0.02 | 0.03 | 0.06 | 0.04 | 0.09 |
| 15 | 0.06 | 0.03 | 0.09 | 0.08 | 0.04 | 0.10 | 0.10 | 0.05 | 0.14 |
| 20 | 0.07 | 0.03 | 0.13 | 0.08 | 0.04 | 0.17 | 0.11 | 0.05 | 0.20 |
| 25 | 0.14 | 0.08 | 0.28 | 0.15 | 0.11 | 0.29 | 0.22 | 0.14 | 0.38 |
| 32 | 0.23 | 0.11 | 0.49 | 0.26 | 0.17 | 0.59 | 0.40 | 0.23 | 0.68 |
| 40 | 0.30 | 0.17 | 0.68 | 0.40 | 0.23 | 0.86 | 0.51 | 0.29 | 1.02 |
| 50 | 0.50 | 0.25 | 0.85 | 0.70 | 0.40 | 1.28 | 0.91 | 0.59 | 1.59 |
| 65 | 0.85 | 0.48 | 1.41 | 1.40 | 0.77 | 2.19 | 1.81 | 0.99 | 3.13 |
| 80 | 1.25 | 0.63 | 1.77 | 2.20 | 1.08 | 3.31 | 2.97 | 1.50 | 4.45 |
| 90 | 1.70 | 0.75 | 2.67 | 2.83 | 1.42 | 4.08 | 4.00 | 2.00 | 5.44 |
| 100 | 2.10 | 1.08 | 3.46 | 4.47 | 2.09 | 5.27 | 6.18 | 2.81 | 7.71 |
| 150 | 5.45 | 2.72 | 8.07 | 10.89 | 5.44 | 10.99 | 16.32 | 8.16 | 13.61 |
| 200 | 10.20 | 5.33 | 15.65 | 21.54 | 10.77 | 20.91 | 33.11 | 16.56 | 28.12 |
| 250 | 18.15 | 9.75 | 26.46 | 38.56 | 19.27 | 35.38 | 51.71 | 25.86 | 49.90 |
| 300 | 25.80 | 13.62 | 39.46 | 59.42 | 29.71 | 62.14 | 79.38 | 39.69 | 83.91 |
Heat Treatment & PWHT for ASTM A234 WP9 Fittings
WP9 (9Cr-1Mo) is an air-hardening ferritic Cr-Mo steel that needs preheat and post-weld heat treatment (PWHT). Before welding heat to 200-260C (400-500F) and keep interpass temperature. Carbides are dissolved and creep resistance is returned by PWHT between 730 and 790C (1350 and 1450F). PWHT temperatures below 730°C are not enough and above 790°C may lead to re-austenitisation. The WP9 fittings are supplied in normalised and tempered condition and the temper temperature is not less than 730°C. Employ the 9Cr-1Mo chemistry filler metals (such as E505 / ER80S-B8). For the purposes of compliance with the PWHT certificate, as well as welding procedure documentation, Metinox Overseas can provide such documents upon request.
Application Uses of ASTM A234 WP9 Pipe Fittings
- Oil & Gas Industry
- Petrochemical Industry
- Power Generation Industry
- Thermal Power Plants
- Chemical Processing Industry
- Refineries
- Boiler Systems
- Heat Exchanger Systems
- Fertilizer Industry
- Pharmaceutical Industry
- Marine & Offshore Industry
- Energy & Utilities Sector
Price List of ASTM A234 WP9 Pipe Fittings
| SR. NO. | DESCRIPTION | NOS | PRICE PER PIECE IN US($) |
|---|---|---|---|
| 1 | CONC. RED. SIZE: 3"X 2" SCH. 80 Alloy Steel A234 WP9 / 2 | EA | $9.01 |
| 2 | ECC. RED. SIZE: 3"X 1.5" SCH. 80 Alloy Steel A234 WP9 / 2 | EA | $13.97 |
| 3 | ELBOW BW, Alloy Steel A234 WP9, 90 D. LR, SIZE: 2" SCH. 80 | EA | $6.44 |
| 4 | ELBOW BW, Alloy Steel A234 WP9, 90 D. LR, SIZE: 3" SCH. 40 | EA | $8.91 |
| 5 | ELBOW BW, Alloy Steel A234 WP9, 90 D. LR, SIZE: 4" SCH. 40 | EA | $20.81 |
| 6 | ELBOW BW, Alloy Steel A234 WP9, 90 D. LR, SIZE: 3" SCH. 80 | EA | $17.86 |
| 7 | CONC. RED. SIZE: 3"X 2" SCH. 40 Alloy Steel A234 WP9 / 2 | EA | $8.93 |
| 8 | ECC. RED. SIZE: 3"X 2" SCH. 80 Alloy Steel A234 WP9 / 2 | EA | $13.89 |
| 9 | CONC. RED. SIZE: 3"X 1.5" SCH. 80 Alloy Steel A234 WP9 / 2 | EA | $11.89 |
| 10 | ELBOW BW, Alloy Steel A234 WP9, 90 D. LR, SIZE: 4" SCH. 80 | EA | $30.71 |
| 11 | ELBOW BW, Alloy Steel A234 WP9, 90 D. LR, SIZE: 6" SCH. 80 | EA | $80.29 |
Frequently Asked Questions
ASTM A234 WP9 pipe fittings are chromium-molybdenum alloy steel fittings used in high-temperature and pressure piping systems.
WP9 is equivalent to ASTM A335 P9 alloy steel, with similar 9Cr-1Mo composition and properties.
WP9 contains higher chromium (around 9%) than WP5 (4–6%), offering better heat resistance and corrosion resistance.
Yes, WP9 fittings are designed for high-pressure and high-temperature service conditions.
Yes, WP9 fittings provide good oxidation and corrosion resistance due to their high chromium content.
Yes. ASTM A234 mandates that Grade WP9 shall be manufactured to fine grain practice. Fine grain improves toughness and creep resistance at elevated temperature and is a unique requirement for WP9 within the A234 alloy grade family.
Preheat to 200–260°C before welding. PWHT at 730–790°C (1350–1450°F) is mandatory to restore mechanical properties and creep resistance. Do not exceed 790°C; partial re-austenitisation may occur. Metinox Overseas supplies PWHT certificates on request.
Yes. ASTM A234 Section 6 requires NDE of welds in WP9 fittings after forming. This is a mandatory quality requirement that must be stated on the purchase order and confirmed on the material certificate.
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