Pressure pipeline

It mainly depends on the medium and pipe diameter; if these meet the requirements, it is considered a pressure pipeline

That’s not the case. The definition of a pressure pipeline refers to pipelines in general, and it doesn’t specify that they have to be metal pipelines; other non-metallic pipelines can also be considered pressure pipelines as long as they meet the relevant conditions

**In the list of 8,000 items in the Special Equipment Catalogue attached to the Announcement by the General Administration of Quality Supervision, Inspection and Quarantine issued on October 30, 2014, titled \"Announcement by the General Administration of Quality Supervision, Inspection and Quarantine on the Revision of the Special Equipment Catalogue (No. 114, 2014)\\", this definition has been changed as follows: A pressure pipeline refers to a tubular device that uses a certain pressure to transport gases or liquids. It is defined as a pipeline whose maximum operating pressure is greater than or equal to 0.1 MPa (gauge pressure), whose medium is gas, liquefied gas, steam, or a liquid that is flammable, explosive, toxic, corrosive, and whose maximum operating temperature is greater than or equal to its standard boiling point, and whose nominal diameter is greater than or equal to 50 mm. Except for pipes with a nominal diameter of less than 150 mm and a maximum operating pressure of less than 1.6 MPa (gauge pressure), as well as the pipes that form part of the equipment used for transporting non-toxic, non-flammable, and non-corrosive gases. Please read carefully – the definition of pressure pipelines has little to do with the material used! :)

It is necessary to define whether it refers to pressure pipelines in a broad sense or regulated pressure pipelines

The maximum operating pressure is greater than or equal to 0.1 MPa (gauge pressure)

If changing the material could allow one to evade regulation, then the flaw would be enormous: lol