The F51 duplex steel ball valve is a ball valve with major components, including the intermediate body, left and right valve bodies, ball, and stem, forged from ASTM A182 F51 or S31803 and S22253. It is suitable for high-pressure pipeline transmission systems in environments with high chloride ion content and sulfide-containing environments. The valve is made of austenitic-ferritic duplex stainless steel, corresponding to the domestic similar grade 022Cr22Ni5Mo3N, with a main composition of 21.0-23.0% Cr, 4.5-6.5% Ni, 2.5-3.5% Mo, and 0.08-0.20% N. To improve its stress corrosion and pitting corrosion resistance in chloride-rich acidic media, this steel has recently been increased in nitrogen content. Its corrosion resistance is between that of 316 and super austenitic stainless steel containing 5-6% Mo, with a pitting resistance equivalent of PREN 29-36, making it a suitable replacement for 317L and 317LN.
ASTM A182 F51 Ball Valve is made of ASTM A182 F51 (UNS S31803) that is a forging material specification for improved corrosion resistance.The ball valve body and trim are all made of ASTM A182 F51.
ASTM A182 F51 is a mixed microstructure of austenitic and ferrite. It has improved strength over ferritic and austenitic steel grades with similar corrosion resistance qualities.
ASTM A182 F51 Ball Valve Specifications
| Part Name | Body/Bonnet | Bolting | Stem | Ball | Seat | Spring |
| Material | ASTM A182 F51 | A193 B8M/A194 8M | ASTM A182 F51 | ASTM A182 F51 | RPTFE, Devlon, PEEK, etc. | Inconel 725 |
ASTM A182 F51 Ball Valve Test Pressure
| Test Type | Test Fluid | Test Pressure (bar) | |||||
| Class 150 | Class 300 | Class 600 | Class 900 | Class 1500 | Class 2500 | ||
| Shell Test | Water | 30 | 77.55 | 155.10 | 232.65 | 38.79 | 64.64 |
| High Pressure Seat Test | Water | 22 | 56.87 | 113.74 | 170.61 | 284.46 | 47.40 |
| Low Pressure Seat Test | Air | 6 | 6 | 6 | 6 | 6 | 6 |
A182 F51 Chemical Composition, %
| ASTM | UNS Designation | C | Mn | P | S | Si | Ni | Cr | Mo | Co | Ti | Other |
| A182 F 51 | S31803 | 0.030 | 2.00 | 0.030 | 0.020 | 1.00 | 4.5–6.5 | 21.0–23.0 | 2.5–3.5 ... | ... | N 0.08–0.20 |
Tensile and Hardness Requirement
| Grade | Tensile Strength, min, ksi [MPa] | Yield Strength, min, ksi [MPa]B | Elongation in 2 in. [50 mm] or 4D, min, % | Reduction of Area, min, % | Brinell Hardness Number, HBW, unless otherwise indicated |
| F51 | 90 [620]C | 65 [450] | 25 | 45 | . . . |
