Standard issues regarding pipe size specifications
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Out of pure curiosity, GB/T17395 classifies the nominal outer diameters of steel pipes into three series, and the commonly used sizes in the chemical industry such as 57, 76, 89, and 108 are also distributed across these three different series; P. We basically use Series II as specified in HG/T20553; is GB/T17395 widely used in domestic chemical projects? Which industry makes use of GB/T17395 the most?
Judging from the poster’s question, it seems they are facing issues with standard selection in the design or procurement of chemical pipelines I have been involved in some projects, and to share my personal experience: the classification system defined by GB/T17395 is intended primarily to cover a wider range of pipe diameters. It is widely used in fields such as oil and gas transmission pipelines, boilers, and heat exchangers, especially for large-diameter steel pipes. In chemical engineering projects, the II series of HG/T20553 is indeed preferred, as this standard fits more closely with the specifications of seamless steel pipes commonly used in the chemical industry (such as 57, 76, 89, 108), and it is also easier to select the necessary fittings such as flanges and pipe fittings. If the poster is working on a domestic project, it’s worth checking whether there are any specified standards for the project itself (for example, if the design documents state that GB/T17395 must be followed). If no such standards exist, it’s usually simpler to follow HG/T20553. Additionally, the tolerances and wall thicknesses may vary among different series specified in GB/T17395; it is advisable to check the actual supply conditions when making a selection, to avoid difficulties in obtaining the tubes later on. It is recommended to follow the design specifications and material lists of specific projects, as there are indeed differences in practices across different industries.
The sections above explain quite clearly the application scenarios of HG/T17395 and GB/T17395. I would like to add some information from my own experience: From the projects I have worked on, in the petrochemical industry (such as within Sinopec), some older projects do specify the use of Series I or III of GB/T17395, especially for high-temperature and high-pressure pipelines, as this allows for the selection of thinner or thicker wall thicknesses, thereby improving the efficiency of using alloy steel pipes. Overall, however, HGⅡ series remains the mainstream for conventional domestic chemical engineering projects, as the compatibility of its components is indeed high. Additionally, some design firms require the comparison of two standards during the initial design phase. If you encounter such a situation, it is recommended to consult sample materials for pipes or flanges to check the hole sizes and bolt specifications, in order to avoid installation problems on site later on. Of course, the specific details should still be based on the project design documents, as the requirements of different owners can vary greatly.
Understood, thank you very much for your reply:handshake