How to inspect valve quality
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Experts in the oil refining industry, how do you inspect newly arrived valves? Private enterprises do not impose any requirements on suppliers; they win bids at low prices. Upon arrival, the valves show no obvious defects in appearance and are of normal sizes, so they are accepted and stored. However, before use, there is significant internal leakage and packing leakage during pressurization, as well as sand holes in the valve body. How serious is your situation{:1_90:}
This post was last edited by CHANGBAISHI on 2025-8-15 07:38. The key is to have contractual provisions in place at the time of procurement. During inspection, the valve must be disassembled for examination, and pressure testing is necessary. Its quality can usually be seen by disassembling it. And it cannot be accepted based solely on appearance. It is best to install and try it out first before making a payment, as it is currently a buyer’s market. It should also be noted here that the relationship between the purchaser and the person responsible for acceptance and use is an issue that requires attention; it is a very delicate relationship, for reference only.
The three major oil companies all have lists of approved suppliers, and they have quite strict requirements; for individual valves, not only is the appearance checked but also the weight. Valve purchases by refineries must be accompanied by technical agreements (standards for procurement and manufacturing), and the valve inspection procedures required by the standards for pressure pipeline installation must be followed.
Disassembly inspection? Do you believe it or not? The pressure test can pass without disassembly, but it fails after disassembly.
Read \"Testing and Inspection of Valves\", published by Standard Press in 2010; read the valve manufacturing supervision guidelines (available from all the major oil companies); review the attachments related to the purchase contract (since your inspection tasks should generally not go beyond what is specified in the contract). Also, investigate the supplier in advance to identify its weaknesses...
It is recommended to change the supplier; I recommend Hubei Wofei Fluid Technology Company
Pressure testing checks the microscopic aspects, while disassembly inspection focuses on the structural aspects and the quality of internal processing. Strictly speaking, dust and impurities that contaminate the valve after it is opened can also damage the valve seat during the next closing process. There are also some special anti-corrosion substances that serve a sealing function as well. This is what needs to be reflected in the contract; one of the tasks during the inspection process is to check whether the sealing performance remains satisfactory after repeated opening and closing. If leakage is detected during pressure testing after switching, it cannot be accepted. There are reasons for leaks; everything is determined by on-site inspection and acceptance, it’s not a matter of belief. For reference.