Are steam pipes considered pressure pipes?

Take a close look at the definition of pressure pipelines; steam pipelines with a diameter of ≥DN50 are all considered pressure pipelines

According to the definition of pressure pipelines in the catalog of special equipment, the media transported include gases, liquefied gases, steam, and liquids that are flammable, explosive, toxic, corrosive, or have a maximum operating temperature equal to or higher than their standard boiling point. Steam exists independently of gases. It is not suitable for conditions where the size is less than 150 mm and the maximum operating pressure is less than 1.6 Mpa. Any pipeline with a nominal diameter of 50 mm or more and a pressure of 0.1 Mpa or more should be classified as a pressure pipeline.

According to the \"Announcement by the General Administration of Quality Supervision, Inspection and Quarantine on the Revision of the ‘Catalogue of Special Equipment’ (No. 114, 2014)\", the definition of pressure pipelines has been revised as follows: Pressure pipelines refer to tubular devices that use a certain pressure to transport gases or liquids. They are defined as those with a maximum operating pressure of 0.1 MPa (gauge pressure) or more, carrying gases, liquefied gases, steam, or liquids that are flammable, explosive, toxic, corrosive, and have a maximum operating temperature equal to or higher than their standard boiling point, and with a nominal diameter of 50 mm or more. 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. Among them, the safety supervision and management of oil and gas pipelines shall also be carried out in accordance with laws and regulations such as the Work Safety Law and the Oil and Gas Pipeline Protection Law. The first one is: pipes with a maximum operating pressure of 0.1 MPa (gauge pressure) or higher, in which the medium is gas, liquefied gas, steam, or a liquid that is flammable, explosive, toxic, corrosive, and has a maximum operating temperature equal to or higher than its standard boiling point; such pipes also have a nominal diameter of 50 mm or more. One of these conditions is met by pressure pipelines. As you mentioned: pressure of 1.0 Mpa, steam transmission – this is clearly a pressure pipeline.

The reply from Baoji Chaosheng Titanium Industry is correct. 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. Among them, the safety supervision and management of oil and gas pipelines shall also be carried out in accordance with laws and regulations such as the Work Safety Law and the Oil and Gas Pipeline Protection Law. At the Beijing pressure pipeline training course this year (May 2018), the instructor mentioned a new regulation in the petroleum industry according to which steam pipelines with a nominal diameter of less than 150 mm and a maximum operating pressure of less than 1.6 MPa (gauge pressure) are considered pressure pipelines. I searched for a long time but couldn’t find it; I’m not sure if it’s an internal rule. Please have the pressure pipeline designers in the oil industry provide relevant regulations so that we can all feel reassured.

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. This falls into two categories: pipelines of the equipment itself, as well as those with a nominal diameter of less than 150 mm and a maximum operating pressure of less than 1.6 MPa (gauge pressure), used for transporting non-toxic, non-flammable, and non-corrosive gases; here, such gases mainly refer to instrument air, compressed air, or non-toxic inert gases ； But steam is clearly not a gas, because steam is water in vaporized form, and that obviously occurs at a temperature higher than the boiling point of water.

Notice from the General Office of the Quality Inspection Administration on Issues Related to the Safety Supervision of Pressure Pipelines and Cylinders (Quality Inspection Office Special [2015] No. 675). Date of issuance: June 24, 2015. To the Quality and Technical Supervision Bureaus (Market Regulation and Supervision Departments) of all provinces, autonomous regions, and municipalities directly under the Central Government: In order to implement the requirements for functional transformation and decentralization of powers, and to further improve the safety supervision of pressure pipelines and cylinders, and in light of the newly revised “Catalogue of Special Equipment” (hereinafter referred to as the “Catalogue”) and the “Technical Regulations for Safety Supervision of Cylinders” (TSG R0006-2014, hereinafter referred to as the “Cylinder Regulations”), the following opinions regarding issues related to the safety supervision of pressure pipelines and cylinders are hereby notified: I. Issues related to the safety supervision of pressure pipelines. (1) Regarding the range of media used in pressure pipelines as listed in the new Catalogue. The toxic, non-flammable, and non-corrosive gases referred to in the definition of pressure pipelines in the new Catalogue – namely, pipelines with a nominal diameter of less than 150 mm and a maximum operating pressure of less than 1.6 MPa (gauge pressure) that transport such gases – do not include liquefied gases, steam, and oxygen.

Steam is not applicable to DN150, 1.6MPa; this one. This mainly refers to things like air and nitrogen