Regulations on whether valves can withstand negative pressure
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Globe control valve, the packing is graphite. When ordering, it was not specified that there will be negative pressure. Now, in fact, negative pressure will occur. The manufacturer said that the packing must be replaced. Are there any regulations in the relevant valve specifications that valves must withstand a certain negative pressure? Are there any negative pressure conditions in the valve testing before leaving the factory?
If negative pressure appears on the pipeline, a vacuum valve should be used. This should be mentioned when ordering and selecting the valve. Conventional valves cannot withstand negative pressure. Mainly by replacing higher performance packing to prevent external gas from entering the inside of the valve and contaminating the medium in the pipeline.