Bursting Disc Protection Device

3 Combination of Safety Valve and Bursting Disc Protection 

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The combination of a bursting disc protection device and a safety valve, as shown in Fig. 7.2, combines the advantages of both protection devices, viz. the practically 100 % leak-tightness with the re-seating after pressure drop. In case of highly corrosive media or a tendency to polymerize the safety valve can be protected by a bursting disc installed in front of it (vid. Pig. 7.2). 

CEN - European Committee for Standardization Brussels wvwv.cenorm.be EN/ISO 4126- Safety Devices for Protection Against Excessive Pressure Part 1 - Safety Valves Part 2 - Bursting Disc Safety Devices Part 3 - Safety Valves and Bursting Disc Safety Devices in Combination Part 4 - Pilot Operated Safety Valves Part 5 - Controlled Safety Pressure Relief Systems Part 6 - Application, Selection and Installation of Bursting Disc Safety Devices Part 7 - Common Data... 

BS EN ISO 4126-2. Safety Devices for Protection Against Excessive Pressure, Part 2 Bursting Disc Safety Devices British Standards Institute London, 2004. 

If solids are allowed to accumulate on the underside of a bursting disc or safety valve, then it is likely that the relief device will not operate when required, at least not at. the required set pressure. Safety valves may be more vulnerable in this respect than bursting discs, and it is common practice to fit a bursting disc upstream of the safety valve to protect it. Further information is given in 10.2.1 and reference 1. 

The subject of safety devices for a liquid-fluorine storage container should be considered individually for each location and application. In the case at hand, a gauge is included in the gas-phase piping, and this gauge incorporates a warning device set for 10 psi. Should the fluorine pressure reach this level, an alarm is sounded in the test cell control room and simultaneously in the Security Guard office, in order to provide protection for periods when the base is not in operation. Further protection is afforded by a gas-phase rupture disc with a burst value of 60 psi. The vent from the rupture disc, as well as the normal vent, is piped to a burner stack where it is burned in combination with propane gas. 

A bursting or rupture disk is a pressure relief device that protects a vessel or system from excess pressures. They have been commonly used in aerospace, aviation, defense, nuclear, and oilfield applications often as a backup device for a conventional safety valve. In this instance, if the pressure increases and the fitted safety valve fails to operate, the rupture disk will burst as required. The discs are usually made from thin metal foil, and gold has been used in some instances because of its ductility and resistance to corrosion. Gold discs fitted to liquid ammonia tanks, for example, have shown good durability in this application compared to other metals. The use of gold in this application was reviewed in the 1970s when this industrial application for gold was more common [10]. 

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