Some differing opinions on SH/T 3059

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1. The pressure pipeline code TSG D0001 specifies how to classify pipelines, but SH/T3059 still classifies pipelines according to its own rules; this seems redundant and may even undermine the uniformity of pipeline standards in China. 2. The determination of design pressure and design temperature is primarily the responsibility of the system designer; specifying it in the standards for selecting pipeline components seems like overstepping one’s role. 3. The design life of the pipeline should be 15 years, to be confirmed by the relevant project owner. 4. The selection of materials under corrosive environmental conditions is a rather complex issue; it requires not only theoretical support but also data on their use or testing provided by manufacturers and factories. The selection requirements specified in standards are applicable in most cases, yet they do not cover all scenarios, and they cannot serve as a basis for standardizing the methods used to select materials. This chapter should serve as an informational appendix. 5. Elbow joints with a miter angle greater than 45° should not be used for hazardous media, flammable media, etc. For example, in the case of large-diameter pipelines such as torch pipelines, cannot inclined elbows with an angle greater than 45° be used? Is there a better option? Is it really necessary to order regular long-radius elbows at a high price? 6. Regulations on the maximum allowable diameter of openings in the flange. If the opening in a flange cover is as large as the nominal diameter of the corresponding pipe, it is equivalent to a flat flange – is it then not allowed to be used? 7. Tees should be used when the design pressure is 2.0 Mpa or higher and the design temperature exceeds 250°C. Those familiar with design should know that there are some size combinations for which it is not possible to use tees entirely. In my opinion, industry standards can be higher than **the standard, but they should also be more aligned with actual design practices. Some of the SH standards do not conform to mainstream design practices; therefore, there should be fewer restrictions (such as the limitations on the use of highly hazardous materials specified in SH/T3161), so as to give designers more autonomy. This will help improve the skills of front-line designers and enhance the overall level of design in our country. Furthermore, **there should be unified regulations; standards should strive to align with a common system, rather than each party acting on its own and creating artificial chaos. Efforts should be made to systematize and standardize China’s chemical pipeline standard system.**