Regarding pressure pipelines

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The classification of low, medium, and high-pressure pipelines is determined by the pressure of the medium inside the pipeline, and this is decided during the design phase. Different pressure levels require different considerations during pipeline construction

The \"Regulations on the Safety Supervision of Special Equipment\" issued and implemented by the State Council on June 1, 2003, further define pressure pipelines as \"tubular devices that use a certain pressure to transport gases or liquids. Such pipelines include those with a maximum working pressure of 0.1 MPa (gauge pressure) or more for gases, liquefied gases, steam, or liquid media that are flammable, explosive, toxic, or corrosive, as well as those with a maximum working temperature equal to or higher than their standard boiling point, and with a nominal diameter of 25 mm or more.\" In other words, the so-called \"pressure pipelines\" mentioned nowadays refer not only to those that are under pressure inside or outside the pipe, but also to those in which media such as \"gases, liquefied gases, and steam\" or \"liquids that may cause combustion, explosion, poisoning, or corrosion\" are transported. 　　Classification of qualification categories and levels for pressure pipeline installation: I. Long-distance pipelines fall under the GA category, with the following level classifications: 1. Long-distance pipelines that meet one of the following conditions are classified as GA1 level: (1) Pipelines that transport toxic, flammable, or combustible gas media, with a design pressure of P > 1.6 Mpa ； 　　(2) Pipelines for transporting toxic, flammable, or explosive liquid fluids, with a transmission distance of ≥200 km and a nominal pipe diameter of DN ≥300 mm ； 　　(3) Pipelines for transporting slurry media, with a transmission distance of ≥50 km and a nominal pipe diameter of DN≥150 mm. 　　2. Long-distance pipelines that meet one of the following conditions are classified as GA2 grade: (1) Pipelines that transport toxic, flammable, or explosive gas media with a design pressure of P ≤ 1.6 Mpa; (2) Pipelines that fall outside the GA1(2) category ； 　　(3) Pipelines outside the GA1(3) range. 　　II. Public pipelines are classified as GB category, with the following grade divisions: GB1 gas pipelines ； 　　GB2 thermal pipeline. 　　Industrial pipelines of category GC are classified as follows: 1. Industrial pipelines that meet one of the following conditions are classified as GC1 grade: (1) Pipelines that transport media with an extreme hazard level as specified in GB5044 \"Classification of Hazards from Occupational Exposure to Toxic Substances\" ； 　　(2) Pipelines that transport flammable gases of Class A or B, or flammable liquids of Class A, as specified in GB50160 \"Code for Fire Protection Design of Petrochemical Enterprises\" and GBJ16 \"Code for Fire Protection Design of Buildings\", and have a design pressure of P ≥ 4.0 MPa ； 　　(3) Pipelines for transporting flammable fluid media or toxic fluid media, with a design pressure of P ≥ 4.0 MPa and a design temperature of ≥ 400°C ； 　　(4) Piping for transporting fluid media with a design pressure of P ≥ 10.0 MPa. 　　2. Industrial pipelines that meet one of the following conditions are classified as GC2 grade: (1) Pipelines that transport flammable gases of categories A or B, or flammable liquids of category A, as specified in GB50160 \"Code for Fire Protection Design of Petrochemical Enterprises\" and GBJ16 \"Code for Fire Protection Design of Buildings\", and whose design pressure is P＜4.0MPa ； 　　(2) Pipelines for transporting flammable fluid media or toxic fluid media, with a design pressure of P < 4.0 MPa and a design temperature of ≥ 400°C ； 　　(3) Pipelines for transporting non-flammable fluid media and non-toxic fluid media, with a design pressure of P＜10MPa and a design temperature of ≥400℃ ； 　　(4) Piping for transporting fluid media, with a design pressure of P＜10 Mpa and a design temperature of ＜400℃. 　　3. GC2-class pipelines that meet one of the following conditions are classified as GC3-class: (1) Pipelines that transport flammable fluid media or toxic fluid media, with a design pressure of P < 1.0 MPa and a design temperature of < 400°C ； 　　(2) Pipelines for transporting non-flammable fluid media and non-toxic fluid media, with a design pressure of P < 4.0 MPa and a design temperature of < 400°C.