Cryogenic piping refers to systems that are used in a wide range of industrial applications that require extremely low temperatures, generally around -300°F (150°C) or lower. Due to such low temperatures, cryogenic pipes face unique corrosion and deterioration challenges.
Cyrogenic piping is also referred to as cold piping.
Implement specifications such as ASME SA-333M, GB/T18984. The seamless steel tubes are applied for low temperature pressure vessel pipeline and low temperature heat exchanger pipeline.
| Usage | Specification | Steel Grade |
| Seamless and Welding Nominal Pipe used for Low Temperature | ASME SA -333M | Gr.3, Gr.6, Gr.8 and so on |
| Seamless Steel Pipe used for Low Temperature Pipeline | GB/T18984 | 16MnDG, 06Ni3MoDG, 06Ni9MoDG and so on |
ASTM A333 (ASME S/A-333) Pipe grades permit low temperature service.
Mechanical requiremnts of ASTM A333 alloy pipe
| Grade | Tensile Strength (MPa） | Yield Point (MPa) | Elongation (%) | |
|---|---|---|---|---|
| Y | X | |||
| Grade 3 | ≥450 | ≥240 | ≥30 | ≥20 |
| Grade 6 | ≥415 | ≥240 | ≥30 | ≥16.5 |
| Grade 8 | ≥690 | ≥515 | ≥22 | |
Chemical Composition (%) of ASTM A333 steel pipe
| Grade | Chemical Composition (%) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | Cr | Ni | Cu | Mo | V | Al | |
| Grade 3 | ≤0.19 | 0.18-0.37 | 0.31-0.64 | ≤0.025 | ≤0.025 | 3.18-3.82 | |||||
| Grade 6 | ≤0.30 | ≥0.10 | 0.29-1.06 | ≤0.025 | ≤0.025 | ||||||
| Grade 8 | ≤0.13 | 0.13-0.32 | ≤0.90 | ≤0.025 | ≤0.025 | 8.40-9.60 | |||||
Products can be ordered in accordance with the client’s requirements.
GB/T18984-2003 standard suitable for -49 to -148 0 F cryogenic pressure vessel piping, and low-temperature heat exchanger tubes seamless steel pipe.
Chemical Compositions(%)
| Grade | C | Si | Mn | P(max) | S | Ni | Mo | V |
| 16MnDG | 0.12-0.20 | 0.20-0.55 | 1.20-1.60 | 0.025 | 0.025 | - | - | - |
| 10MnDG | <=0.13 | 0.17-0.37 | <=1.35 | 0.025 | 0.025 | - | - | <=0.07 |
| 09DG | <=0.12 | 0.17-0.37 | <=0.95 | 0.025 | 0.025 | - | - | <=0.07 |
| 09Mn2VDG | <=0.12 | 0.17-0.37 | <=1.85 | 0.025 | 0.025 | - | - | <=0.12 |
| 06Ni3MoDG | <=0.08 | 0.17-0.37 | <=0.85 | 0.025 | 0.025 | 2.5-3.7 | 0.15-0.30 | <=0.05 |
Longitudinal mechanical properties of the steel pipes
| Grade | Tensile strength | Lower yield strength（Rcl/Mpa） | Elongation | |
| Rm/Mpa | W.T.<=16mm | W.T.>16mm | A/% | |
| 16MnDG | 490-665 | >=325 | >=315 | >=30 |
| 10MnDG | >=400 | >=240 | >=35 | |
| 09DG | >=385 | >=210 | >=35 | |
| 09Mn2VDG | >=450 | >=300 | >=30 | |
| 06Ni3MoDG | >=455 | >=250 | >=30 | |
(Not more than 25 mm) outside diameter and wall thickness of the steel pipe shall conform to GB/T 17395-1998 Table 1 provisions. According to the requirements of the demand side, the supply and demand sides consultation, produce the provisions specifications steel pipe.
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