Liquid ammonia leak: What is the interlock setting value for the water curtain and mist system? What are the interlock value standards for toxic gas leaks?
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In our plant, when the ammonia concentration in the liquid reaches 39 ppm, the water spray system activates automatically as part of the interlock mechanism. Where does this 39 ppm come from? Are there **specified** interlock values for related toxic gas leaks?
39ppm should not be a **regulation
This should be the minimum sensitivity of the detector
Check the standard: SH3063-1999 Design Code for Gas Detection and Alarm Systems in Petroleum and Chemical Enterprises
This standard has been repealed; the standard currently in use is: Design Code for Detection and Alarm of Flammable and Toxic Gases in Petrochemical Enterprises (GB50493-2009)； The alarm range for toxic media is set at: 0–300% MAC (PC-STEC) ； Or 0-30% IDLH ；
Thank you to the folks above! I know it’s 39 ppm. The limit for ammonia concentration is 30 milligrams per cubic meter; when converted to ppm, it comes out to just a little over 39, less than 40. Rounded off, it’s 39 ppm
The MAC for ammonia is 30 mg/m3~