Pressure Piping Classification and Procurement Requirements
Pressure piping belongs to special equipment and is classified by medium, pressure, temperature, and hazard level. Piping of different classes has clearly differentiated requirements in material selection, standard selection, inspection and testing, document archiving, and acceptance control. Many procurement personnel confuse the class boundaries of GC1, GC2, GC3, and other piping classes, simply using pressure values as the basis for selection, which causes problems such as low-class materials being used in high-risk working conditions, missing documents, and failure to pass supervisory inspection. Based on TSG 31 and GB/T 20801 specifications, this article explains the logic of pressure piping classification and the elements for class determination, sorts out the procurement technical requirements, document requirements, factory inspection, and incoming control points for pipes, fittings, flanges, and fasteners according to different classes, clarifies common procurement misunderstandings, and establishes a classified and compliant procurement control system to ensure the compliant commissioning of pressure piping as special equipment.