Scope of pressure pipelines

This question is indeed worth careful consideration. I understand that your concern is this: if the pipe diameter is less than DN50 and, per regulations, it falls outside the scope of regulation, does that mean that even the functions related to discharge and waste removal can be eliminated? However, I think it’s important to distinguish between “regulatory scope” and “engineering necessity.” Following the guidelines, such pipes with small diameters may indeed not fall under mandatory regulatory requirements; however, if they are used for discharging or removing waste in a process context, they often still need to be installed in engineering terms, even in the absence of regulatory mandates. For example, low-point drainage is primarily used to remove accumulated water or impurities within the pipelines promptly, in order to avoid water hammer or corrosion. From the perspectives of safety and operational efficiency, it is still recommended to retain this system ； High-point emission is intended for exhaust during driving or parking, or to prevent air blockage; it is also a practical necessity ； It is recommended to refer to GB 50041 or relevant pipeline design codes to see if there are any general regulations regarding discharge and waste treatment facilities; do not decide to eliminate such provisions based solely on the table of contents. Of course, it ultimately depends on the medium, pressure, and actual operating conditions of your pipeline. If you’re not sure, it’s best to check with colleagues in design or safety management again; don’t skip that step in the piping to avoid potential problems.

Pipes smaller than DN50 are not subject to inspection

No. According to the latest revised Regulations on the Safety Supervision of Special Equipment in 2024, DN50 pipes will no longer be considered pressure pipes, but high-point discharge and low-point drainage pipes may still require compliance with other safety and regulatory requirements. Although high-point discharge and low-point drainage pipes with a nominal diameter of less than DN50 are no longer classified as pressure pipes under the new standards, and thus do not require strict safety oversight measures such as regular inspections and mandatory certification akin to those applied to pressure pipes, they still need to meet other relevant safety and environmental requirements. For example, they may need to meet specific engineering standards, design specifications, or industry standards to ensure their safety and reliability during use. Furthermore, if these pipelines carry toxic, flammable, explosive, or corrosive media, certain safety and management measures may be required even if their nominal diameter is less than DN50. Therefore, even though these pipelines are no longer subject to the regulations governing pressure pipelines, this does not mean that their safety and compliance issues can be completely ignored. In practice, appropriate measures should be taken after comprehensive consideration of the specific circumstances and relevant regulatory requirements.

Shouldn’t the production requirements be met first? How can zero emissions and no waste discharge meet production requirements?