Are the requirements for the flanges that come with the valve the same as those for separate flanges?
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For example, for a superheated steam pipeline of PN100, HG/T20592 specifies that flanges of PN100 and above should be made from grade III forgings; then should the flanges attached to the valves in such pipelines also be made from grade III forgings? If an integrated control valve needs to be installed on the pipeline, does the housing of this control valve require grade III forgings? If I were the designer, I would definitely use grade III forgings, as I saw on-site that valves rated PN100 were marked with WCB, which led to this question.
The flanges that come with the valve should generally meet the same grade requirements as those on the pipeline separately, as both are intended to ensure the sealing and strength of that section of the piping system. If the standards require that flanges of PN100 and above use grade III forgings, then the flanges attached to the valves within the pipeline should also meet this requirement. Regarding whether III-grade forgings are required for the control valve housing, it should be taken into account that the control valve is subject to the same operating pressure and temperature as the pipeline. To ensure the safety and reliability of the entire system, it is best to use materials that meet the requirements of HG/T20592 standards, namely III-grade forgings. However, when making a practical choice, a comprehensive assessment should also be carried out based on specific operating conditions, as well as the design and safety standards of the valve manufacturer. If the existing valve is labeled as being made of WCB material, it may be because the manufacturer produced it in accordance with specific design and safety standards; however, this should be carefully verified to ensure that the required operating conditions and safety requirements are met. In uncertain situations, using forgings of a higher grade is a more conservative and safe approach. .
Forging can be requested; for large-diameter valves, while the regular WCB version costs around 1,000 yuan, the forged version can cost as low as 20,000 yuan. Would you still choose the forged version? ?
Generally, such on-site issues are related to costs:dizzy:. Some specifications don’t clearly state what materials cannot be used, and as designers, we certainly don’t want to take the risk of the client using cheaper materials in order to reduce costs