1999 "Pipeline Valves for Oil and Gas Industry Pipeline Conveyor Systems" / API 6D: 2002 "Pipeline Valves". Standard specifies the flange connection and welding connection gate valve, ball valve, check valve and plug valve terms, structure type and parameters, ordering requirements, technical requirements, materials, inspection rules, test methods, signs and so on. Applicable to the nominal pressure of PN16 ~ PN420, nominal size DN15 ~ DN1200 natural gas and oil pipeline with gate valve, ball valve, check valve and plug valve. The main differences between GB / T 19672 and ISO 14313 / API 6D are as follows: (1) The standard compilation format is different from the ISO / API standard according to the requirements of GB / T 1.1-2000. (2) Some of the terms and definitions in international standards are used. (3) Increase the nominal pressure PN16, PN25, PN40. (4) modified the content of the ordering requirements. (5) an increase of more than DN1000 ball valve structure length size. (6) Increased valve housing connection bolt thread requirements. (7) According to China's laws and regulations require welding and inspection requirements. (8) provides the inspection rules of the valve. GB / T 19672 Description of the main technical content: (1) the terms on the full-diameter valve, reducing valve, shrink valve, one-way valve, two-way valve, locking device to explain. In order to accurately use the standard requirements. (2) The structure gives the typical structure and connection of gate valve, ball valve, plug valve and check valve used in long-distance pipeline. (3) pressure - temperature grade valve shell material used in line with the provisions of GB 9131, the standard is the application of GB 9131 pressure-temperature reference. (4) The length of the structure The length of the foreign pipeline valves are connected to the structural length of the API 6D requirements, the standard API 6D according to the structural length of the valve in order to exchange. For one end of the welded connection, the other end of the flange connection valve structure length requirements. (5) Representation of Paths Referring to the representation of the path of API 6D, the nominal dimensions of the valve and the actual path diameter are specified. To facilitate the distinction: full-diameter valve, reducing valve, shrink-valve, clearly shows the valve nominal size (with the same pipe) and the actual channel diameter. (6) Minimum diameter and channel shape For long-distance pipeline cleaning and unblocking requirements, please refer to API 6D lists the minimum channel of the valve, and the channel cross-section shape is regulated. (7) The structural requirements for the long-distance pipeline valve on the performance and operation of the use of the requirements of the provisions of the structure. The provisions of the pipeline valve operating torque and operational performance requirements. (8) Materials List of commonly used valve shell material varieties, anti-corrosion requirements of anti-corrosion measures, hardness requirements. Valve welding and welding requirements. (9) Test Refer to API 6D for the inspection contents of all kinds of valves, test requirements, dwell time and test methods. Standard by the National Valve Standardization Technical Committee (SAC / TC188) centralized. August 1, 2005 began.