Design, manufacturing standards, and inspection for pipelines at on-site natural gas pressure regulation stations

Requirements 1. Design and manufacturing standards: (1) The pipeline design shall be based on the \"Safety Code for Boilers and Pressure Vessels (TB/T 11-2005)\", the **standard \"Technical Regulations for Boiler Pipeline Engineering (JC/T 22-95)\」, and the **standard \"Design Regulations for Underground Steel Gas Pipelines (DB11/265-2014)\」. (2) The pipes are made of high-strength cold-formed welded structural steel; qualified-grade welding flux is used for the pipe joints, and they comply with **relevant welding technical standards. (3) The antioxidants for pipeline materials should employ cathodic protection or metal protection; when plastic wrapping is used, plastic antioxidants must be applied. (4) The installation of pipelines must comply with the requirements of the \"Technical Specifications for the Installation of Underground Steel Gas Pipelines\", and account for the deformation of pipeline sections during installation. 2. Inspection requirements: (1) There should be dedicated personnel to conduct inspections before and after pipeline construction, and the records obtained shall serve as the standards for ensuring construction quality. (2) After the installation of the air pipes in the factory is completed, a safety inspection of the pipes should be carried out to ensure that their installation quality meets the required standards. (3) For the inspection of the inner wall roughness of pipes, it is necessary to ensure that the inner wall surface is smooth and even, with the inspection tolerances being within the range specified by the GB/T 7678.1-1999 standard. (4) The pipeline welding areas must be thoroughly cleaned, and the welding surfaces should be polished. It is also necessary to check whether the fill quality, integrity, and adhesion of the welds meet the standard requirements. (5) When designing the pipeline network of a pressure regulation station, parameters such as the gas pressure that the network must withstand during pressure regulation and the length of the pipelines should be taken into account to ensure that the network can meet the requirements for normal operation. -