In clause 7.2.7 of the petrochemical fire protection codes, regarding utility pipelines and pipelines for flammable gases, flammable liquids, and liquefied gases...
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According to clause 7.2.7 of the petrochemical fire protection codes, check valves should be installed on utility pipes as well as on pipes carrying flammable gases, flammable liquids, or liquefied gases; isolation valves should be placed at their bases. What exactly are these utility pipes referred to here?
On these devices, nitrogen and process water are normally used; compressed air and steam are rarely connected； It is mainly to prevent backflow under abnormal conditions, which could lead to accidents. Thank you!
It is when purge and displacement pipelines (used to displace or purge with utility media such as water, steam, air, nitrogen, etc.) are added to these pipelines for flammable gases, flammable liquids, and liquefied hydrocarbons that isolation valves and check valves need to be installed at the point where the utility pipelines meet the material pipelines, in order to prevent the material from entering the utility pipelines. Sometimes, double valves and 8-shaped blind plates are also used in such cases.