Are hydrochloric acid pipes with a steel lining and PTFE considered pressure pipes? Is it necessary to inform me before installation?
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I’m seeking help from experts. I currently have a pipeline carrying dilute hydrochloric acid with a pressure of 0.3 MPa (concentration: 15%), and the material of this pipeline is steel lined with Teflon. Is it necessary to go to a specialized inspection agency to submit an installation notification for this type of pipeline, just like with steam pipelines that are subject to high pressure, before installing it?
Haven’t done it yet; for now it’s still PP. I’ll learn about it first
It needs to be noted that the Special Inspection Agency generally does not conduct inspections. Inspection mainly focuses on pipelines with welded connections. Steel-lined pipes are not generally inspected by specialized inspection agencies, as the lining is manufactured in a factory, the steel pipe that serves as the framework comes equipped with leakage inspection holes, and they are connected using flanges. It was stated that it’s your program, so it needs to be done. In the catalog of special equipment, code 7150 refers to composite pipes, while 71F0 refers to pipes made of non-metallic materials.
According to the definition of pressure pipelines, these are pipes with a 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 whose maximum operating temperature is equal to or higher than its standard boiling point; such pipes also have a nominal diameter of 25 mm or more. This belongs to pressure pipelines, but generally, the leakage inspection carried out by specialized inspection agencies involves non-destructive testing of the welds; the lining tube may not be inspected.
Now, only pipes with a diameter of 50 mm or more are considered pressure pipes
Not necessary; it does not belong to pressure pipelines