I am wondering how to design a open drain seal/fire pot (installed for hazardous drain system)and what is the criteria that determines the water seal level? Is there any standard that is applicable to such?
A parallel situation is the water seal in a flare drum to prevent flash back.
Looking in my notes, reference "A" calls for 6-inch min submergence.
Reference "B" calls for 3-4 inch submergence.
If your concern is flashback prevention, 3-6 inches of water seal should be a good design.