The identification issue of process pressure pipelines
Thread Content
Our company is currently developing a small-scale equipment system, which includes a pipeline that is approximately 5 meters long, with a DN50 size and a pressure rating of PN25MPa. The fluid flowing through this pipeline is deionized water at room temperature, and it is used for high-pressure cleaning. We are facing an urgent issue: there is disagreement among the engineering firms regarding the nature of this pipeline. It is not clear whether it constitutes a pressure pipeline, and if it does, then its design and manufacturing processes will become much more complicated. When we looked up definitions related to pressure pipelines, we were unable to find any definition for pipelines carrying such high-pressure, harmless media. Could any expert help us determine what type of pipeline this is and what the basis for that determination is? Thank you very much
The material of this pipeline is 304 stainless steel
There’s a book titled “National Training Materials for Pressure Pipeline Design Approvers” on the forum; I’ll go and take a look at it
I’ve been searching for a long time for the training materials for pressure pipeline design approvers nationwide, but I couldn’t find them. However, I did come across a safety regulation regarding pressure pipelines issued by the State Council; the definition of pressure pipelines given in that regulation does not apply to our pipelines either
Safety technical specifications for special equipment – Category GC, Grade GC1(3): Pipes that transport fluid media and have a design pressure of 10.0 MPa or more, or a design pressure of 4.0 MPa or more with a design temperature of 400 degrees or more. Therefore, the pipeline you are referring to for cleaning is a pressure pipeline, classified as G1(3)
GC category, GC1 grade (3): Piping that transports fluid media and has a design pressure of 10.0 MPa or more, or a design pressure of 4.0 MPa or more with a design temperature of 400 degrees or more. Is this sentence to be understood as follows: For fluid media with a design pressure greater than 10 MPa, regardless of the temperature of the medium, they all fall into category G1. For fluid media with a design pressure between 4 MPa and 10 MPa, they must also meet the condition that the medium temperature is above 400 degrees in order to be classified as G1?
The medium is deionized water; as long as the operating temperature is below 100 degrees of the standard boiling point, it is not a pressure pipeline regardless of the pressure. This post was last edited by huagong63 on 2009-3-31 13:38.]
I’m really confused now. What LZ said is the same as what I understand, but it’s in line with the way I interpreted it in my previous reply – that’s how the person in charge of acceptance at the engineering company thinks. I’m extremely frustrated; I can’t convince them
Water or water-like media, as long as the operating temperature does not exceed the standard boiling point, are not considered pressure pipelines regardless of the pressure level. For specific details, refer to the definition of special equipment in the \"Regulations on the Safety Supervision of Special Equipment\"
Yeah, I got it. I’ll go explain it later. Thanks to everyone for their help
According to the Provisions on the Safety Supervision of Special Equipment, a pressure pipeline is defined as follows: A pressure pipeline is a tubular device that uses certain pressure to transport gases or liquids. It refers to pipelines in which the maximum operating pressure is greater than or equal to 0.1 MPa (gauge pressure), and which are used for transporting gas, liquefied gas, steam, or liquid media that are flammable, explosive, toxic, corrosive, with a maximum operating temperature greater than or equal to their standard boiling point; such pipelines also have a nominal diameter of more than 25 mm. Therefore, deionized water does not belong to pressure pipelines, no matter what the pressure is.
The broad definition of pressure pipelines should be determined in accordance with the 2003 version of the \"Regulations on the Safety Supervision of Special Equipment\"; the definition provided for fluids excludes such pipes, hence they are not considered pressure pipelines.
My understanding is the same as that of floors 7 and 9.
The 1996 Regulations on the Safety, Installation, and Inspection of Pressure Piping stipulate that they are not considered pressure piping