Chapter 8 Pressure Relief Device

Bench or test stand testing Testing of a pressure relief device on a test stand using an external pressure source with or without an auxiliary lift device, to determine some or all of its operating characteristics, without necessarily flowing the rated capacity. This is required on a regular basis when the valve is taken into the maintenance cycle (see Chapter 10) at least to see that there is no shift on the set pressure and that the valve would open correctly during a pressure upset. 

This chapter covers those aspects of the mechanical design of chemical plants that are of particular interest to chemical engineers. The main topic considered is the design of pressure vessels. The designs of storage tanks, heat exchanger tube sheets, and pressure-relief devices are also discussed briefly. 

Detailed information regarding compressed gas containers, pressure regulators, pressure relief devices, and valve outlet connections is contained in Chapters 5 through 9. Additional safe handling procedures for compressed gases can be found in CGA P-1 [7], and in CGA AV-1, an audiovisual safety training program of the same title. 

Each cargo tank must be provided with one or more pressure relief devices, which, unless otherwise specified for a particular product, must be pressure relief valves of the spring-loaded type. Refer to Chapter 8 for detailed information on pressure relief devices. 

This chapter describes the various types of pressure relief devices used in the compressed gas industry and the standards developed to describe their design criteria, performance characteristics, and applications. The sections covered are ... 

Pressure relief valves. Pressure relief devices used on cargo tanks and portable tanks are similar to the CG-7 devices described for compressed gas cylinders earlier in this chapter, but... 

Type CG-2 (fusible plug device). This type of device is described earlier in this chapter under compressed gas cylinder pressure relief devices. Only the CG-2 fusible plug with a nominal melt... 

Refer to the Introduction to Part II for information on pressure relief devices. A full alphabetical list of gases and device assignments can be found in Chapter 8, Table 8-2. 

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