Technical requirements for pipeline valves
★ technical requirements for pipeline valves:
GB / t19672-2005 is revised and formulated by adopting iso14313:1999 petroleum and natural gas industry; pipeline transmission system; pipeline valves’ > valves / api6d:2002 pipeline valves’ > valves. The standard specifies the terms, structural types and parameters, ordering requirements, technical requirements, materials, inspection rules, test methods, marks and other contents of gate valves, ball valves, check valves and plug valves connected by flanges and welding. It is applicable to gate valve, ball valve, check valve and plug valve for natural gas and oil transmission pipeline with nominal pressure of PN16 ~ pn420 and nominal size of DN15 ~ DN1200.
★ the main differences between GB / t19672 and iso14313 / API6D are as follows:
(1) The standard preparation format is in accordance with the requirements of GB / T1.1-2000, which is different from the ISO / API standard.
(2) Some of the terms and definitions in the standard are adopted.
(3) The nominal pressures PN16, PN25 and PN40 are added.
(4) The contents of the order requirements are modified.
(5) The structural length of ball valves larger than DN1000 is added.
(6) The requirements for connecting bolt thread of valve shell are added.
(7) The welding and inspection requirements shall be specified according to the requirements of Chinese laws and regulations.
(8) The inspection rules of valves are specified.
★ description of main technical contents of GB / t19672:
(1) Terminology
Explain the full diameter valve, reduced diameter valve, reduced mouth valve, one-way valve, two-way valve and locking device. So as to correctly use the relevant requirements of the standard.
(2) Structure
The typical structure and connection forms of gate valve, ball valve, plug valve and check valve used in long-distance pipeline are given.
(3) Pressure temperature class
The shell material used for the valve shall comply with the provisions of gb9131, and the pressure temperature standard of gb9131 shall be applied.
(4) Structure length
The structural length of relevant pipeline valves in foreign countries is in accordance with the structural length requirements of API6D, and the standard is also in accordance with the structural length of API6D, so that the valves can be interchanged. There are requirements for the structural length of valves with one end connected by welding and the other end connected by flange.
(5) Representation of diameter
The nominal size and actual channel diameter of the valve are specified with reference to the expression of the diameter of API6D. It is convenient to distinguish: full diameter valve, reduced diameter valve and reduced mouth valve, and clearly indicate the nominal size of the valve (the same as the pipeline) and the actual channel diameter.
(6) Zui small diameter and channel shape
For the cleaning and dredging requirements of long-distance pipelines, the Zui small channel of the valve is listed with reference to API6D, and the channel section shape is specified.
(7) Structural requirements
The structures that affect the performance of long-distance pipeline valves and have requirements for operation are specified. The requirements for operating torque and operating performance of pipeline valves are specified.
(8) Material
The commonly used valve shell materials, anti-corrosion treatment measures and hardness requirements for sulfur resistance are listed. Requirements for welding and repair welding of valves.