Can a circulating water pipeline be classified as a pressure pipeline?
Thread Content
This post was last edited by su*ubin on 2009-5-24 09:32. It is the designer’s fault that those components in the design documents that should be classified as pressure pipes are not marked as such. But can components that fall outside the category of pressure pipes still be marked as such? Judges have discretion; do designers also have it? I think this pipeline is very important, such as for the cooling water of critical pumps. I would also like to raise the standards and include it in the category of pressure pipelines – is that possible? A device with so many pipelines, each of which has its own function – which one is unimportant? If it’s unimportant, then it can be omitted. The circulating water pipeline is an important utility; any problem with it could lead to a shutdown of the equipment. Although the risk in such cases is low, it still could cause dangers such as overheating or overpressure of the equipment. I think it makes sense to include it as well. Such issues might be dismissed by those working in large design institutes; I don’t care about that – I just follow the specifications strictly. However, such problems arise for design firms affiliated with factories or for designers who are closely tied to actual production processes, because there are many such issues in practice. The less strict and less important things tend to receive little attention during procurement and construction, which often leads to problems.
There’s no need. For the cooling water of important pumps, two systems are generally used: one that utilizes circulating water and another that uses fresh water. Moreover, the pipe diameters are very small and the pressures are low; isn’t it excessive to classify them as pressure pipelines? Even for the main circulating water pipelines, as long as they are constructed and inspected in accordance with the requirements, there are no problems. Moreover, some factories may have loop pipelines available for use.
Agree with the view from the 2nd floor. Whether it is classified as a pressure pipeline or not is a different matter from its importance.
According to the definition of pressure pipelines, circulating water pipelines should not be considered as such. If you consider this pipeline to be important, you can request that its construction and inspection be carried out in accordance with the standards for pressure pipelines; once classified as a pressure pipeline, the facility will have to undergo inspections every year, which is also not in line with the regulations
Regardless of whether it is important or not, according to the definition of pressure pipelines, circulating water pipes do not fall under the category of pressure pipelines, and they are non-toxic and harmless. . . .
Pressure pipelines refer to tubular devices that use a certain pressure to transport gases or liquids. They are defined as pipelines for gas, liquefied gas, steam, or liquid media that are flammable, explosive, toxic, corrosive, and have a maximum operating temperature equal to or higher than their standard boiling point, with a maximum working pressure of 0.1 MPa (gauge pressure), and a nominal diameter of more than 25 mm. The above is taken from the \"Regulations on the Safety Supervision of Special Equipment (State Decree No. 373)\”; circulating water is a liquid, so it is not included
According to the current definition of pressure pipelines, circulating water pipelines do not fall under the category of pressure pipelines
The definition of pressure pipelines does not take into account the importance of the pipes within the system, which is a drawback; of course, it is not possible to create a definition that encompasses all aspects of the pipes’ importance. These shortcomings must be addressed through the specific design decisions made by the designer, such as selecting the appropriate process, pipe materials, wall thickness, conducting pressure tests, and implementing various protective measures for the pipes.
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 equipment that uses 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, used for transporting gases, liquefied gases, steam, or liquid media that are flammable, explosive, toxic, or corrosive, and whose maximum working temperature is equal to or higher than their standard boiling point; furthermore, these pipelines must have a nominal diameter of 25 mm or more.\" In other words, the so-called \"pressure pipelines\" mentioned today 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 levels: 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 substances, 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) Pipes 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 whose design pressure is 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) Pipes that transport fluid media and have 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 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 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 < 10 MPa and a design temperature of ≥ 400°C ； (4) Pipelines 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. Circulating water pipes do not belong to pressure pipes
Water pipes with a pressure of over 10 MPa should not be considered pressure pipes, but they are very dangerous