The P-Number system is established by ASME to classify materials based on their weldability. It is primarily used for WPS/PQR documentation and material compatibility analysis.
Our welding capabilities cover the material groups listed in the table below:
| Material Type | ASME P-Group | Representative Materials & Standards | Common Applications & Characteristics |
| Carbon Steel | P-1 | SA-516 Gr.70, SA-106 Gr.B, SA-36, SA-105 | Commonly used in pressure vessels and piping; cost-effective and easy to fabricate |
| Low Alloy Steel | P-2, P-5, P-10, P-11 | SA-182 F5/F9, SA-213 T22, SA-335 P11/P22, SA-517 | Suitable for high-temperature and high-pressure systems, such as boilers and thermal oil systems |
| Austenitic Stainless Steel | P-8 | 304 / 316 / 321 / 347 / 309 / 310 (SA-240, SA-182) | Excellent corrosion resistance; widely used for general industrial applications |
| Duplex Stainless Steel | P-10h | S31803 / S32205 / S32750 (SA-240, SA-789) | High strength and excellent corrosion resistance; commonly used in seawater and chloride environments |
| Pure Nickel | P-10i | Nickel 200 / 201 (SB-162) | Excellent resistance to acids and alkalis; ideal for highly corrosive environments (also known as Monel®) |
| Nickel Alloys: Ni-Cu | P-10j | Alloy 400 (SB-127, SB-564) | Resistant to chloride stress corrosion cracking; suitable for marine environments (also known as Monel®) |
| Nickel Alloys: Ni-Cr | P-10j | Alloy 600 / 601 (SB-168) | Excellent oxidation resistance at high temperatures; often used in furnaces and high-temp tubing (Inconel®) |
| Nickel Alloys: Ni-Mo | P-10k | Alloy B / B-2 (SB-333, SB-335) | Exceptional resistance to hydrochloric acid and other aggressive media (e.g., Hastelloy® B series) |
| Nickel Alloys: Ni-Cr-Mo | P-10k | Alloy C-276 / C-2000 (SB-575) | Superior resistance to a wide range of corrosive chemicals; ideal for chemical and pharmaceutical systems (Hastelloy® C series) |
| Nickel Alloys: Fe-Ni-Cr | P-10j | Alloy 800 / 825 (SB-407) | High resistance to heat and corrosion; excellent thermal stability (Incoloy® series) |
| Copper & Copper Alloys | P-31 | C12200 (red copper), C70600 (Cu-Ni), C44300 (naval brass, Cu-Zn 70/30), C71500 (Cu-Ni 70/30), C68700 (aluminum brass) | Commonly used in general-purpose heat exchangers |
| Titanium | No defined P-Group | Grade 1–2 (SB-265, SB-338, SB-348) | Excellent resistance to seawater and salt environments; high corrosion resistance but limited heat resistance |