(150c) Emergency Block Valves

An Emergency Block Valves (EBV) is used as a means of isolating flammable or toxic substances in the event of a leak or fire.  The installation, and use, of EBV's in many hydrocarbon services will significantly reduce the potential of fire and explosion damages caused by loss of hydrocarbon containment situations; and a general improvement in overall plant safety for both capital assets, and operating and maintenance personnel.  In Hydrocarbon, and / or toxic services; EBV's will serve to mitigate the potential of significant environmental releases. 

This paper is to be presented in a tutorial format.  The items to be covered include the code basis of EBV's (API RP-553, NFPA 58 specific requirements for LPG service), the types of valves to be used; the selection of manual or automatic valve actuation; guidelines for determining if EBV's are recommended based on equipment services, and hydrocarbon inventories; general installation requirements; and integration with other safety instrumented systems within the processing unit.