Marzouk Steel, based in Tunis, Tunisia, is a leading manufacturer and supplier of premium steel products, serving industries that demand durability, performance, and reliability. Among its specialized offerings are Alloy Steel P91 Pipes, engineered for high-pressure and high-temperature applications. Manufactured using advanced technology and stringent quality control, these pipes provide consistent strength, toughness, and long-term reliability. Marzouk Steel ensures that every P91 pipe meets international standards, giving engineers and fabricators confidence for critical systems in power plants, petrochemical facilities, and industrial processes where safety, efficiency, and durability are essential.
Alloy Steel P91 Pipes are chromium-molybdenum-vanadium (Cr-Mo-V) alloy steel pipes designed for superior high-temperature strength, creep resistance, and oxidation resistance. The chemical composition typically includes carbon, chromium, molybdenum, and vanadium, enhancing toughness, thermal stability, and fatigue resistance. P91 pipes exhibit excellent tensile and yield strength, high impact resistance, and durability under continuous high-pressure and high-temperature conditions. Heat treatment optimizes hardness, strength, and creep resistance, making P91 pipes ideal for demanding industrial applications such as ultra-supercritical boilers and high-pressure pipelines.
| Type | Seamless / ERW / Welded / Fabricated |
| Standard | ASTM A335 P91, SA335 P91 (with IBR Test Certificate) |
| Size | 1/2” NB to 36” NB |
| Length | Standard Double & In Cut length also. |
| Schedules | SCH 40, SCH 80, SCH 160, SCH XS, SCH XXS, All Schedules |
| Tolerance | Cold drawn pipe: +/-0.1mm
Cold rolled pipe: +/-0.05mm |
| Application | Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service |
| End | Plain End, Beveled End, Treaded |
| Craft | Cold rolled and Cold drawn |
| available in Form of | Round, Square, Rectangular, Hydraulic Etc. |
| Origin | European, Japanese, Korean, US, Russian, Indian (Strictly No Chinese Material) |
| Specialized in | Large Diameter ASTM A335 P91 Pipe |
| Additional Testing | NACE MR 0175, NACE TM0177, NACE TM0284, HIC TEST, SSC TEST, H2 SERVICE, IBR, etc. |
| Thickness | 3-12mm |
| Alloy Steel P91 | C | Cr | Mn | Mo | P | S | Si |
| 0.08-0.12 | 8.00 – 9.50 | 0.30-0.60 | 0.85 – 1.05 | 0.020 max | 0.010 max | 0.20 -0.50 |
| Tensile Strength, MPa | Yield Strength, MPa | Elongation |
| 585 min | 415 min | 20 min |
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
Marzouk Steel is a major manufacturer and a supplier of premium Alloy Steel P91 pipe in Tunis, the Tunisia. With specialization in steel solutions, we offer a variety of products including carbon steel, alloy steel, light steel and galvanized steel. Our wide bearing has pipes, pipes, flanges, pipe fittings, forged fittings, sheets and plates. We are famous for our reliable distribution and extraordinary customer service, and are committed to offering high quality steel materials that ensure durability and better performance in different industrial applications. We are committed to skill, and we are your reliable partners for all steel requirements.
| ASTM | ASME | Equivalent material | JIS G 3458 | UNS | BS | DIN | ISO | ABS | NK | LRS |
|---|---|---|---|---|---|---|---|---|---|---|
| A335 P91 | SA335 P91 | T91, K90901, X10CrMoVNb9-1, 1.4903 | K91560 |
| O.D.(mm) x Thickness(mm) | O.D(mm) x Thickness(mm) | O.D(mm) x Thickness(mm) |
|---|---|---|
| 38.1 x 3.2 | 57.0 x 4.9 | 76.2 x 4.0 |
| 38.1 x 4.0 | 57.0 x 6.3 | 76.2 x 5.0 |
| 38.1 x 6.3 | 57.0 x 7.9 | 76.2 x 6.3 |
| 42.4 x 3.2 | 60.3 x 3.2 | 82.5 x 4.5 |
| 42.4 x 4.0 | 60.3 x 3.6 | 88.9 x 3.2 |
| 44.5 x 3.2 | 60.3 x 5.0 | 88.9 x 3.6 |
| 44.5 x 6.3 | 63.5 x 3.2 | 88.9 x 4.0 |
| 48.3 x 3.2 | 63.5 x 3.6 | 101.6 x 3.6 |
| 48.3 x 3.6 | 63.5 x 4.0 | 101.6 x 4.5 |
| 50.8 x 4.5 | 63.5 x 6.3 | 101.6 x 6.3 |
| 51.0 x 3.2 | 63.5 x 7.9 | 114.3 x 3.6 |
| 51.0 x 3.6 | 70.0 x 3.2 | 114.3 x 5.0 |
| 51.0 x 6.3 | 70.0 x 3.6 | 139.7 x 4.0 |
| 57.0 x 3.2 | 70.0 x 6.3 | 139.7 x 5.0 |
| 57.0 x 3.6 | 76.2 x 3.6 | 139.7 x 6.3 |
| Size NPS | Pipe O.D. | Wall Thickness | Pipe I.D. | Weight per Foot | Standard to XXHY | Schedule Pipe # | Section Modulus | Gallon Capacity Per Linear Foot |
| 1/2 | 0.84 | 0.109 | 0.622 | 0.85 | STD | 40 | .0407 | .0158 |
| 0.147 | 0.546 | 1.09 | XHY | 80 | .0478 | .0122 | ||
| 0.188 | 0.464 | 1.31 | 160 | .0528 | .0088 | |||
| 0.294 | 0.252 | 1.72 | XXHY | .0577 | .0026 | |||
| 3/4 | 1.05 | 0.113 | 0.824 | 1.13 | STD | 40 | .0705 | .0277 |
| 0.154 | 0.742 | 1.48 | XHY | 80 | .0853 | .0225 | ||
| 0.219 | 0.612 | 1.95 | 160 | .1006 | .0153 | |||
| 0.308 | 0.434 | 2.44 | XXHY | .1103 | .0077 | |||
| 1 | 1.315 | 0.133 | 1.049 | 1.68 | STD | 40 | .1328 | .0449 |
| 0.179 | 0.957 | 2.17 | XHY | 80 | .1606 | .0374 | ||
| 0.250 | 0.815 | 2.85 | 160 | .1904 | .0271 | |||
| 0.358 | 0.599 | 3.66 | XXHY | .2136 | .0146 | |||
| 1 1/4 | 1.66 | 0.140 | 1.380 | 2.27 | STD | 40 | .2346 | .0777 |
| 0.191 | 1.278 | 3.00 | XHY | 80 | .2913 | .0666 | ||
| 0.250 | 1.160 | 3.77 | 160 | .3421 | .0549 | |||
| 0.382 | 0.896 | 5.22 | .4110 | .0328 | ||||
| 1 1/2 | 1.90 | 0.145 | 1.610 | 2.72 | STD | 40 | .3262 | .1058 |
| 0.200 | 1.500 | 3.63 | XHY | 80 | .4118 | .0918 | ||
| 0.281 | 1.338 | 4.86 | 160 | .5079 | .0730 | |||
| 0.400 | 1.100 | 6.41 | .5977 | .0494 | ||||
| 2 | 2.375 | 0.109 | 2.157 | 2.64 | 10 | .4205 | .1898 | |
| 0.154 | 2.067 | 3.66 | STD | 40 | .5606 | .1743 | ||
| 0.218 | 1.939 | 5.03 | XHY | 80 | .7309 | .1534 | ||
| 0.250 | 1.875 | 5.68 | .8045 | .1434 | ||||
| 0.281 | 1.813 | 6.29 | .8666 | .1344 | ||||
| 0.344 | 1.687 | 7.47 | 160 | .9806 | .1161 | |||
| 0.436 | 1.503 | 9.04 | XXHY | 1.1043 | .0922 | |||
| 2 1/2 | 2.875 | 0.120 | 2.635 | 3.53 | 10 | .6870 | .2833 | |
| 0.203 | 2.469 | 5.80 | STD. | 40 | 1.0640 | .2487 | ||
| 0.216 | 2.443 | 6.14 | 1.1169 | .2435 | ||||
| 0.250 | 2.375 | 7.02 | 1.2468 | .2301 | ||||
| 0.276 | 2.323 | 7.67 | XHY | 80 | 1.3386 | .2202 | ||
| 0.375 | 2.125 | 10.02 | 160 | 1.6371 | .1842 | |||
| 0.552 | 1.771 | 13.71 | XXXHY | 1.9971 | .1280 | |||
| 3 | 3.50 | 0.120 | 3.260 | 4.34 | 1.0411 | .4336 | ||
| 0.156 | 3.188 | 5.58 | 1.3122 | .4147 | ||||
| 0.172 | 3.156 | 6.12 | 1.4265 | .4064 | ||||
| 0.188 | 3.124 | 6.66 | 1.5342 | .3984 | ||||
| 0.216 | 3.068 | 7.58 | STD. | 40 | 1.7241 | .3840 | ||
| 0.250 | 3.000 | 8.69 | 1.9372 | .3672 | ||||
| 0.281 | 2.938 | 9.67 | 2.1207 | .3521 | ||||
| 0.300 | 2.900 | 10.26 | XHY | 80 | 2.2253 | .3431 | ||
| 0.438 | 2.624 | 14.34 | 160 | 2.8774 | .2811 | |||
| 0.600 | 2.300 | 18.6 | XXHY | 3.4243 | .2158 | |||
| 3 1/2 | 4.0 | 0.120 | 3.760 | 4.98 | 10 | 1.3776 | .5768 | |
| 0.226 | 3.548 | 9.12 | STD. | 140 | 2.3939 | .5136 | ||
| 0.250 | 3.500 | 10.02 | 2.6001 | .4998 | ||||
| 0.281 | 3.438 | 11.17 | 2.8562 | .4821 | ||||
| 0.318 | 3.364 | 12.52 | XHY | 80 | 3.1400 | .4617 | ||
| 0.636 | 2..728 | 22.87 | XXHY | 4.8795 | .3085 | |||
| 4 | 4.5 | 0.120 | 4.260 | 5.62 | 10 | 1.7612 | .7404 | |
| 0.156 | 4.188 | 7.24 | 2.2354 | .7156 | ||||
| 0.188 | 4.124 | 8.67 | 2.6296 | .6942 | ||||
| 0.203 | 4.094 | 9.32 | 2.8173 | .6838 | ||||
| 0.219 | 4.062 | 10.02 | 3.0184 | .6725 | ||||
| 0.237 | 4.026 | 10.80 | STD. | 40 | 3.2145 | .6613 | ||
| 0.250 | 4.000 | 11.36 | 3.3611 | .6528 | ||||
| 0.281 | 3.938 | 12.67 | 60 | 3.7021 | .6326 | |||
| 0.312 | 3.876 | 13.97 | 4.0273 | .6126 | ||||
| 0.337 | 3.826 | 15.00 | XHY | 80 | 4.2713 | .5972 | ||
| 0.438 | 3.624 | 19.02 | 120 | 5.1790 | .5361 | |||
| 0.531 | 3.438 | 22.53 | 160 | 5.8997 | .4822 | |||
| 0.674 | 3.152 | 27.57 | XXHY | 6.7927 | .4054 | |||
| 5 | 5.563 | 0.188 | 5.187 | 10.80 | 4.1161 | 1.0979 | ||
| 0.219 | 5.125 | 12.51 | 4.7279 | 1.0716 | ||||
| 0.258 | 5.047 | 14.63 | STD. | 40 | 5.4500 | 1.0391 | ||
| 0.281 | 5.001 | 15.87 | 5.8644 | 1.0204 | ||||
| 0.312 | 4.939 | 17.51 | 6.4074 | .99647 | ||||
| 0.344 | 4.875 | 19.19 | 6.9358 | .9696 | ||||
| 0.375 | 4.813 | 20.80 | XHY | 80 | 7.4300 | .9449 | ||
| 0.500 | 4.563 | 27.06 | 120 | 9.2534 | .8495 | |||
| 0.625 | 4.313 | 32.99 | 160 | 10.7976 | .7590 | |||
| 0.750 | 4.063 | 38.59 | XXHY | 12.0954 | .6734 | |||
| 6 | 6.625 | 0.109 | 6.407 | 7.59 | 5 | 3.5769 | 1.6748 | |
| 0.134 | 6.357 | 9.30 | 10 | 4.3475 | 1.6488 | |||
| 0.156 | 6.313 | 10.79 | 5.0107 | 1.6260 | ||||
| 0.188 | 6.249 | 12.94 | 5.9351 | 1.5937 | ||||
| 0.203 | 6.219 | 13.94 | 6.3804 | 1.5780 | ||||
| 0.219 | 6.187 | 15.00 | 6.8261 | 1.5620 | ||||
| 0.250 | 6.125 | 17.04 | 7.6905 | 1.5306 | ||||
| 0.280 | 6.065 | 18.99 | STD. | 40 | 8.4958 | 1.5008 | ||
| 0.312 | 6.001 | 21.06 | 9.3416 | 1.4688 | ||||
| 0.344 | 5.937 | 23.10 | 10.111 | 1.4391 | ||||
| 0.375 | 5.875 | 25.05 | 10.893 | 1.4082 | ||||
| 0.432 | 5.761 | 28.60 | XHY | 80 | 12.224 | 1.3541 | ||
| 0.500 | 5.625 | 32.74 | 13.711 | 1.2909 | ||||
| 0.562 | 5.501 | 36.43 | 120 | 14.9806 | 1.2346 | |||
| 0.625 | 5.375 | 40.09 | 16.1821 | 1.1787 | ||||
| 0.719 | 5.187 | 45.39 | 160 | 17.8243 | 1.0977 | |||
| 0.864 | 4.897 | 53.21 | XXHY | 20.025 | .9784 | |||
| 1.000 | 4.625 | 60.13 | 21.7719 | .8727 | ||||
| 1.125 | 4.375 | 66.14 | 23.1237 | .7809 |
Alloy Steel P91 Pipes are widely used in industries that require high strength, temperature resistance, and long-term reliability. They are commonly applied in ultra-supercritical boilers, heat exchangers, high-pressure steam pipelines, and power generation equipment. P91 pipes are designed to withstand extreme temperature and pressure conditions while maintaining structural integrity and performance. Engineers and fabricators trust P91 pipes for critical applications in power plants, petrochemical industries, and industrial systems where durability, efficiency, and safety are essential. Their combination of toughness, thermal stability, and creep resistance ensures long-term, reliable operation in high-performance environments.
Marzouk Steel is a leading manufacturer, supplier and exporter of high-quality Carbon Steel, Alloy Steel, Mild Steel and Galvanized Steel products. Our extensive product range includes Pipes, Tubes, Flanges, Pipe Fittings, Forged Fittings, Sheets and Plates, catering to various industries in Tunis, Tunisia.
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