Introduction To Technical Conditions And Standards For Pipeline Valves

GB/T 19672-2005 was modified and formulated based on ISO14313:1999 "Petroleum and Natural Gas Industry Pipeline Transportation System Pipeline Valves"/API 6D:2002 "Lined Valve". The standard specifies the terms, structural types and parameters, ordering requirements, technical requirements, materials, inspection rules, test methods, markings, etc. of flange-connected and welded gate valves, ball valves, check valves and plug valves. It is applicable to gate valves, ball valves, check valves and plug valves for natural gas and oil pipelines with nominal pressures of PN16~PN420 and nominal sizes of DN15~DN1200. The main differences between GB/T 19672 and ISO 14313/API 6D are as follows: (1) The standard writing format is in accordance with the requirements of GB/T 1.1-2000, which is different from the ISO/API standard. (2) Some of the terms and definitions in the international standard are adopted. (3) Nominal pressures PN16, PN25, and PN40 have been added. (4) The ordering requirements have been modified. (5) The structural length dimensions of ball valves larger than DN1000 have been added. (6) The requirements for the thread of the valve body connection bolts have been added. (7) The welding and inspection requirements are specified in accordance with the laws and regulations of my country. (8) The inspection rules for valves are specified. Explanation of the main technical contents of GB/T 19672: (1) Terminology Explanations are given for full-bore valves, reduced-bore valves, reduced-mouth valves, one-way valves, two-way valves, and locking devices. This allows for accurate use of the relevant requirements of the standard. (2) Structures The typical structural forms and connection forms of gate valves, ball valves, plug valves, and check valves used in long-distance pipelines are given. (3) Pressure-temperature ratings The body materials used in the valves comply with the provisions of GB 9131, and the standard applies the pressure-temperature benchmark of GB 9131. (4) Structural length The structural length of foreign pipeline valves is in accordance with the structural length requirements of API 6D, and the standard also follows the structural length of API 6D to facilitate valve interchangeability. There are requirements for the structural length of valves with one end welded and the other end flanged. (5) Diameter indication Referring to the diameter indication of API 6D, the indication method for the nominal size of the valve and the actual channel diameter is specified. To facilitate the distinction: full-diameter valve, reduced-diameter valve, and reduced-mouth valve, the nominal size of the valve (the same as the pipeline) and the actual channel diameter are clearly indicated. (6) Minimum diameter and channel shape In view of the requirements for cleaning and dredging of long-distance pipelines, the minimum channel of the valve is listed in reference to API 6D, and the channel cross-sectional shape is specified. (7) Structural requirements The structure that affects the performance of long-distance pipeline valves and has requirements for operation and use is specified. The operating torque and operating performance requirements of pipeline valves are specified. (8) Materials The commonly used valve shell material varieties, anti-corrosion treatment measures for sulfur resistance requirements, and hardness requirements are listed. Requirements for welding and repair welding of valves. (9) Test: API 6D specifies the inspection contents, test requirements, pressure holding time and test methods for various valves. The standard is under the jurisdiction of the National Technical Committee for Valve Standardization (SAC/TC188). It came into effect on August 1, 2005.