Seeking advice on issues with valve internals
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For a certain petrochemical valve, the design requirement specifies trim material of 13Cr/STL. However, STL is not indicated on the on-site nameplate nor in the quality certification documents. Is this considered a problem? I earnestly request advice from experts
Model Z41Y/H, where Y/H denotes STL/13Cr.
Yes, this is considered a problem. The material of the valve’s internal components should comply with the design requirements; if the design specifies 13Cr/STL, then STL should be indicated on the on-site nameplate and in the quality certification documents, otherwise there may be a problem of the material not meeting the specified standards. The supplier should be contacted for verification. .
I see it represents cemented carbide, but it’s not necessarily STL, right? ?
Y indeed stands for cemented carbide, but such conventional gate valves are generally designated as STL by default; the manufacturer’s model number is Z41Y/H, which is also a model number established in accordance with technical specifications. If it is necessary to verify the material composition of the products provided by the manufacturer, the components and hardness of the valve sealing surface can be analyzed to determine whether they meet the standard requirements.
Yes, Y usually represents cemented carbide, and does not necessarily refer specifically to STL (steel). If STL is specifically mentioned in the design requirements, it should be clearly indicated. If only Y is indicated without specifying the material type, this may lead to misunderstandings or failure to meet the design requirements. It is necessary to further verify whether the material specifications meet the design requirements. .
The design documents specify that the valves shall be manufactured in accordance with the API600 standard, yet the valve model designation follows the GB standard. I feel strange about it; is there anything wrong?
The trim information will be indicated on the nameplate; if there is no nameplate, the corresponding material certification must be provided through other documents.
Do you want it to be reflected on the document, or do you want it to be used on the actual product? The Y in the model usually denotes STL; in practice, a spectral analysis of the sealing surface is required to determine whether STL has been used.
Isn’t it indicated on its nameplate and quality certification documents? It’s only specified in the model number; after all, the sealing surface is also very important. I’ve seen that other valve manufacturers indicate 13Cr/STL on their nameplates
There are no mandatory requirements regarding the material of the sealing surface in the standards for compiling valve nameplates; it is up to the manufacturer to specify this information. If in doubt, it is still necessary to generate a spectrum oneself for confirmation.