Pressure pipeline

Pressure pipelines have specified pressure values: 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 defined in GB 5044‑85 \"Classification of Hazards from Occupational Exposure to Toxic Substances\", highly hazardous gaseous media, and highly hazardous liquid media whose operating temperature is above their standard boiling point；   (2) Pipelines that transport flammable gases of Class A or B, or flammable liquids of Class A (including liquefied hydrocarbons), as specified in GB 50160–1999 \"Code for Fire Protection Design of Petrochemical Enterprises\" and GB 50016–2006 \"Code for Fire Protection Design of Buildings\", and whose design pressure is P ≥ 4.0 MPa ；   (3) Pipelines that transport fluid media with a design pressure of P ≥ 10.0 MPa, or a design pressure of P ≥ 4.0 MPa and a design temperature of 400°C or higher ； 2) Pipes that are not GC3 grade as specified below, and those whose medium toxicity level, fire hazard (flammability), design pressure, and design temperature are lower than those specified for GC1 grade above, are classified as GC2 grade.   3) Pipelines that transport non-toxic, non-flammable fluid media, with a design pressure of P≤1.0MPa, and a design temperature greater than –20°C but less than 185°C, are classified as GC3 grade.

According to the \"HGT 20660-2017 Standards for Classifying the Toxicity Hazards and Explosion Risks of Chemical Media in Pressure Vessels\", methanol is characterized as a \"single **component\" (Table 5.0.2-1 NO.155).\"； Pipes that meet the definition of pressure pipes as specified in item 3 of Article 3 – namely, pipes that transport non-toxic, non-flammable fluid media, with a design pressure of P≤1.0 MPa, and a design temperature greater than –20°C but less than 185°C – are classified as GC3 grade. ”According to the regulations, it should belong to the GC3 pipeline.

Does GC1 not specify any requirements for design pressure or pipe diameter?

Methanol has a flash point of 11 degrees and is classified as a Class A B liquid, falling under GC2

Definitely. The definition of a pressure pipeline: 1. The maximum operating pressure is greater than or equal to 0.1 MPa. 2. The nominal diameter is greater than 25 mm. 3. The medium being transported is gas, steam, liquefied gas, a liquid whose maximum operating temperature is equal to or higher than its standard boiling point, or a liquid that is flammable, explosive, toxic, or corrosive.

Don’t mislead people; there are only GC1 and GC2 now.

You’re right, thank you for the reminder. I just checked Announcement No. 3 issued by the Market Supervision Bureau in 2019.