6.6.2.11 Frangible discs

(c) the reference temperature corresponding to the rated pressure for frangible discs

(c) the reference temperature corresponding to the rated pressure for frangible discs and

Emergency pressure relief devices may be of the spring loaded, frangible or fusible type.

Frangible discs not in series with a spring loaded pressure relief device are not permitted.

Frangible discs shall rupture at nominal pressure equal to the test pressure of the shell.

Particular attention shall be given to the requirements of 6.6.2.5.1 and 6.6.2.8.3 if frangible discs are used.

The frangible disc shall rupture at a nominal pressure 10 above the start to discharge pressure of the relief device.

The frangible discs shall rupture at a nominal pressure 10 above the start to discharge pressure of the relief device.

When a frangible disc is inserted in series with the required pressure relief device, the space between the frangible disc and the pressure relief device shall be provided with a pressure gauge or suitable tell tale indicator for the detection of disc rupture, pin holing, or leakage which could cause a malfunction of the pressure relief system.

When no spring loaded pressure relief device is used, the frangible disc shall be set to rupture at a nominal pressure equal to the test pressure.

6.6.2.11.1 Except as specified in 6.6.2.8.3, frangible discs shall be set to rupture at a nominal pressure equal to the test pressure throughout the design temperature range.

6.6.4.6.2 Shells for non flammable refrigerated liquefied gases and hydrogen may in addition have frangible discs in parallel with the spring loaded devices as specified in 6.6.4.7.2 and 6.6.4.7.3.

6.6.4.7.2 For non flammable refrigerated liquefied gases (except oxygen) and hydrogen, this capacity may be achieved by the use of frangible discs in parallel with the required safety relief devices.

However, protection against particles 1 10 cm in size can be achieved through special features in the design of space systems (redundant subsystems, frangible structures, pressure vessel isolation capabilities etc.).

Solar array designs can minimize the effects of damage from collisions with small particles by using designs that have multiple electrical paths and that minimize structural mass, i.e. frangible configurations.

Unless a portable tank in dedicated service is fitted with an approved relief device constructed of materials compatible with the load, such device shall comprise a frangible disc preceding a spring loaded device.

6.6.2.8.4 Every portable tank with a capacity less than 1,900 litres shall be fitted with a pressure relief device which may be a frangible disc when this disc complies with the requirements of 6.6.2.11.1.

Unless a portable tank in dedicated service is fitted with an approved relief device constructed of materials compatible with the load, the relief device shall comprise a frangible disc preceding a spring loaded pressure relief device.

4.2.1.13.8 The emergency relief devices may be of the spring loaded or frangible types designed to vent all the decomposition products and vapours evolved during a period of not less than one hour of complete fire engulfment as calculated by the following formula

The space between the frangible disc and the device shall be provided with a pressure gauge or a suitable tell tale indicator. This arrangement permits the detection of disc rupture, pinholing or leakage which could cause a malfunction of the pressure relief device.

However, protection against particles 1 10 cm in size can be achieved through special features in the design of space systems (redundant subsystems, frangible structures, pressure vessel isolation capabilities, maximum physical separation of redundant components and paths of electrical and fluid lines etc.).

6.6.2.8.1 Every portable tank with a capacity not less than 1,900 litres and every independent compartment of a portable tank with a similar capacity, shall be provided with one or more pressure relief devices of the spring loaded type and may in addition have a frangible disc or fusible element in parallel with the spring loaded devices except when prohibited by reference to 6.6.2.8.3 in the applicable portable tank instruction in 4.2.4.2.6.