Abstract
The problem of disposal of inflammable vapors released from safety relief valves in petroleum refineries and similar types of units is treated in this paper. Three approaches are presented which are being employed in the design of pressure-relieving systems with the objective of reducing costs without sacrificing safety: (a) Use of diffusion equations to determine maximum concentration of gas at grade when a given quantity is discharged from a safety relief valve into the atmosphere. The solution assists in determining whether an open or closed system should be used. (b) Procedure whereby in closed systems, the sizes of discharge piping may be reduced by setting the relief valve below vessel design pressure. (c) Application of special type of safety relief valve in closed systems, in order to eliminate or reduce effects of back pressure.
