Rupture disk size

For rupture disk sizing the downstream pressure is assumed to reach the critical flow pressure although the dowm stream pressure initially may be much low er. Under these conditions the flow through the orifice that the disk produces on rupture is considered to be at critical flow. The assumptions of critical pressure do not apply... 

Determine the rupture disk size required to relieve the pressure in a process vessel with the following conditions k = 1.4. 

Rupture Disk Sizing, Catalog 1-1110, Continental Disc Corporation, 1991. 

Impact of Rupture Disk Size on Vessel Repressurization for Water at 130°C. Data taken from Ogiso et al. (1972)... 

In this chapter, following topics will be discussed type of pressure relief devices, their characteristics, ASME code PRD set pressure, maximum operating pressure, contingency analysts, pressure reliefvalve and rupture disk sizing, pressure relief valve inlet/outlet piping sizing, Eind PRD selection. 

A is required effective PRV oriflce area or rupture disk area, in inch W is vapor relief load, in Ib/hr T is relief temperature, in R Z is vapor compressibility factor at relief conditions. Let Z=1.0 for ideal gas. (see note 5 at end of this section) M is relief vapor molecular weight C is a coefficient calculated by q. (7b) or let it be 315 Kd is effective discharge coefficient Kb is backpressure correction factor Kc is a correction factor for install a rupture disk at PRV inlet, set kc to 1.0 for rupture disk sizing only Pi is PRD inlet pressure, in psia,... 

Kd equals 0.975 for PRV sizing, if manufacturer s Kd is not available. It equals 0.62 for rupture disk sizing. 

Kd equals 0.74 for PRV sizing, if manufacturer s Kd is not avmlable, Kd equals 0.62 for rupture disk sizing. Kw equals 1.0 for conventional, pilot PRV, and rupture disk sizing. For balanced-bellows PRV, use Figure 9 to estimate its value. 

The following eonsiders a situation that involves all vapor relief. The size of a vapor phase rupture disk required is determined hy assuming that all of the heat energy is absorbed by the vaporization of the liquid. At the set temperature, the heat release rate q is... 

Determine size and specifications for all safety relief valves and/or rupture disks for process safety relief (including run-a-way reactions) and relief in case of external fire. 

Figure 7-7B. Pressure level relationships for rupture disk devices. Reprinted by permission, Sizing, Seiection and instaiiation of Pressure Relieving Dewces in Refineries, Part 1 Sizing and Selection," API RP-520, 5th Ed., July 1990, American Petroleum Institute.

Figure 7-8B. Standard rupture disk. A prebulged rupture disk available in a broad range of sizes, pressures, and metals. Courtesy of B.S. B. Safety Systems.

The minimum net flow area is the calculated net area after a complete burst of the disk with appropriate allowance for any structural members which may reduce the net flow through the rupture disk derdce. The net flow area for sizing purposes shall not exceed the nominal pipe size area of the rupture disk device. 

Rupture disks are used for the same purpose as safety valves and, in addition, serve to relieve internal explosions in many applications. If the pressure rise can be anticipated, then the volume change corresponding to this change can be calculated by simple gas laws, and the capacity of the disk at the relieving pressure is knowm. The system must be examined and the possible causes of overpressure and their respective relief capacities identified before a reliable size can be determined. See Figure 7-14. 

Sizing for Combinalion of Rupture Disk and Pressure Relief Valve in Series Combinalion... 

Rupture disks when properly sized and located on the potentially overpressure vessel have been shown to provide the best protection for a deflagration but not a detonation [54],... 

There have been at least six different formulas proposed and used to determine the proper and adequate size of rupture disk openings for a specific relieving condition. The earlier studies of Sylvander and Katz [25] led to the development of the ASME and API recommendations. This approach assumes that a fire exists under or around the various vessels in a process. This fire may have... 

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