First of all,WP5,WP9,WP11,WP22 are steel grades from standard ASTM A234,《SPECIFICATION FOR PIPING FITTINGS OF WROUGHT CARBON STEEL AND ALLOY STEEL FOR MODERATE AND HIGH-TEMPERATURE SERVICE》,alloy pipe fittings of ASTM A234 WP1/ WP5 / WP9 / WP11,WP22 etc.(ASTM A234 WP5 Pipe Fitting)
ASTM A234,carbon steel material commonly used in WPB and WPC,alloy materials commonly used WP5/WP9/ WP11/WP12/WP22/WP91 etc.,these materials regardless of the chemical composition,mechanical properties and tensile properties are different.The specific values are as follows:
Chemical Composition
| Grade and | Composition, % | |||||||
| Marking SymbolA | Carbon | Manganese | Phosphorus, | Sulfur, | Silicon | Chromium | Molybdenum | |
| WP1 | 0.28 max | 0.30–0.90 | 0.045 | 0.045 | 0.10–0.50 | . . . | 0.44–0.65 | |
| WP12 CL1, | 0.05–0.20 | 0.30–0.80 | 0.045 | 0.045 | 0.60 max | 0.80–1.25 | 0.44–0.65 | |
| WP12 CL2 | ||||||||
| WP11 CL1 | 0.05–0.15 | 0.30–0.60 | 0.030 | 0.030 | 0.50–1.00 | 1.00–1.50 | 0.44–0.65 | |
| WP11 CL2, | 0.05–0.20 | 0.30–0.80 | 0.040 | 0.040 | 0.50–1.00 | 1.00–1.50 | 0.44–0.65 | |
| WP11 CL3 | ||||||||
| WP22 CL1, | 0.05–0.15 | 0.30–0.60 | 0.040 | 0.040 | 0.50 max | 1.90–2.60 | 0.87–1.13 | |
| WP22 CL3 | ||||||||
| WP5 CL1, | 0.15 max | 0.30–0.60 | 0.040 | 0.030 | 0.50 max | 4.0–6.0 | 0.44–0.65 | |
| WP5 CL3 | ||||||||
| WP9 CL1, | 0.15 max | 0.30–0.60 | 0.030 | 0.030 | 1.00 max | 8.0–10.0 | 0.90–1.10 | |
| WP9 CL3 | ||||||||
TABLE 2 Tensile Requirements
Which WP5 is a kind of material,divided WP5CL1 and WP5CL3 are low alloy steel materials,for WP5 and WP9 grade steel pipe fittings,the highest hardness is 217HB.
WP9 is an alloy steel,corresponding to the domestic material 1Cr9Mo,used for some more special pipe manufacturing,WP9 steel grade should be made of fine grain steel.(ASTM A234 WP9 Pipe Fitting)
WP11 is the most common alloy material in piping industry.People used the 15Crmo material instead of WP11,recent years,there are correct WP11 raw materials in the market for pipes and fittings production.(ASTM A234 WP11 Pipe Fitting)
WP22 corresponding pipe is A355 P22,mostly corresponding to the national standard 12Cr2Mo.
