Rupture disc

Last updated
A rupture disc (burst) Rupturedisc burst.JPG
A rupture disc (burst)
Pressure-effect acting at a rupture disc Rupturedisc close up.JPG
Pressure-effect acting at a rupture disc

A rupture disc, also known as a pressure safety disc, burst disc, bursting disc, or burst diaphragm, is a non-reclosing pressure relief safety device that, in most uses, protects a pressure vessel, equipment or system from overpressurization or potentially damaging vacuum conditions.

Contents

A rupture disc is a type of sacrificial part because it has a one-time-use membrane that fails at a predetermined differential pressure, either positive or vacuum and at a coincident temperature. The membrane is usually made out of metal, [1] but nearly any material (or different materials in layers) can be used to suit a particular application. Rupture discs provide instant response (within milliseconds or microseconds in very small sizes) to an increase or decrease in system pressure, but once the disc has ruptured it will not reseal. Major advantages of the application of rupture discs compared to using pressure relief valves include leak-tightness, cost, response time, size constraints, flow area, and ease of maintenance.

Rupture discs are commonly used in petrochemical, aerospace, aviation, defense, medical, railroad, nuclear, chemical, pharmaceutical, food processing and oil field applications. They can be used as single protection devices or as a secondary relief device for a conventional safety valve; if the pressure increases and the safety valve fails to operate or can not relieve enough pressure fast enough, the rupture disc will burst. Rupture discs are very often used in combination with safety relief valves, isolating the valves from the process, thereby saving on valve maintenance and creating a leak-tight pressure relief solution. It is sometimes possible and preferable for highest reliability, though at higher initial cost, to avoid the use of emergency pressure relief devices by developing an intrinsically safe mechanical design that provides containment in all cases.

Although commonly manufactured in disc form, the devices also are manufactured as rectangular panels ('rupture panels', 'vent panels' or explosion vents) and used to protect buildings, enclosed conveyor systems or any very large space from overpressurization typically due to an explosion. Rupture disc sizes range from 0.125 in (3 mm) to over 4 ft (1.2 m), depending upon the industry application. Rupture discs and vent panels are constructed from carbon steel, stainless steel, hastelloy, graphite, and other materials, as required by the specific use environment.

Rupture discs are widely accepted throughout industry and specified in most global pressure equipment design codes (American Society of Mechanical Engineers (ASME), Pressure Equipment Directive (PED), etc.). Rupture discs can be used to specifically protect installations against unacceptably high pressures or can be designed to act as one-time valves or triggering devices to initiate with high reliability and speed a sequence of actions required.

Two disc technologies

There are two rupture disc technologies used in all rupture discs, forward-acting (tension loaded) and reverse buckling (compression). Both technologies can be paired with a bursting disc indicator to provide a visual and electrical indication of failure. [2]

In the traditional forward-acting design, the loads are applied to the concave side of a domed rupture disc, stretching the dome until the tensile forces exceed the ultimate tensile stress of the material and the disc bursts. Flat rupture disc do not have a dome but, when pressure is applied, are still subject to tension loaded forces and are thus also forward-acting discs. The thickness of the raw material used in manufacturing (also known as web thickness in graphite discs) and the diameter of the disc determines the burst pressure. Most forward-acting discs are installed in systems with a 80% or lower operating ratio. [3]

In later iterations on forward-acting disc designs, precision-cut or laser scores in the material during manufacturing were used to precisely weaken the material allowing for more variables to control of the burst pressure. This approach to rupture discs, while effective, does have limitations. Forward-acting discs are prone to metal fatigue caused by pressure cycling and operating conditions that can spike past recommended limits for the disc, causing the disc to burst at lower than its marked burst pressure. Low burst pressures also pose a problem for this disc technology. As the burst pressure lowers, the material thickness decreases. This can lead to extremely thin discs (similar to tin foil) that are highly prone to damage and have a higher chance of forming pinhole leaks due to corrosion. These discs are still successfully used today and are preferred in some situations.

Reverse buckling rupture discs are the inversion of the forward-acting disc. The dome is inverted and the pressure is now loaded on the convex side of the disc. Once the reversal threshold is met, the dome will collapse and snap through to create a dome in the opposite direction. While that is happening, the disc is opened by knife blades or points of metal located along the score line on the downstream side of the disc. By loading the reverse buckling disc in compression, it is able to resist pressure cycling or pulsating conditions. The material thickness of a reverse buckling disc is significantly higher than that of a forward-acting disc of the same size and burst pressure. The result is greater longevity, accuracy and reliability over time. Correct installation of reverse buckling discs is essential. If installed upside down, the device will act as a forward acting disc and, due to the greater material thickness, may burst at much higher than the marked burst pressure. [4]

Blowout panel

Blowout panels, also called blow-off panels, areas with intentionally weakened structure, are used in enclosures, buildings or vehicles where a sudden overpressure may occur. By failing in a predictable manner, they channel the overpressure or pressure wave in the direction where it causes controlled, directed minimal harm, instead of causing a catastrophic failure of the structure. An alternative example is a deliberately weakened wall in a room used to store compressed gas cylinders; in the event of a fire or other accident, the tremendous energy stored in the (possibly flammable) compressed gas is directed into a "safe" direction, rather than potentially collapsing the structure in a similar manner to a thermobaric weapon.

Military applications

Blow-off panels are used in ammunition compartments of some tanks to protect the crew in case of ammunition explosion, turning a catastrophic kill into a lesser firepower kill. Blowout panels are installed in several modern main battle tanks, including the M1 Abrams.

In military ammunition storage, blowout panels are included in the design of the bunkers which house explosives. Such bunkers are designed, typically, with concrete walls on four sides, and a roof made of a lighter material covered with earth. In some cases this lighter material is wood, though metal sheeting is also employed. The design is such that if an explosion or fire in the ammunition bunker (also called a locker) were to occur, the force of the blast would be directed vertically, and away from other structures and personnel.

Blowout panels had been in the past been considered as a possible solution to magazine explosions on battleships. However battleship designs since the 1920s instead used the all or nothing armor scheme, particularly with its armored citadel encompassing the battleship's vitals including machinery and magazines, and in the case of magazine penetration the only recourse is to flood the magazine. The lack of blowout panels has resulted in catastrophic damage during the magazine explosions of several battleships including Tirpitz and Yamato .

Applications in biology

Some models of gene gun also use a rupture disc, but not as a safety device. Instead, their function is part of the normal operation of the device, allowing for precise pressure-based control of particle application to a sample. In these devices, the rupture disc is designed to fail within an optimal range of gas pressure that has been empirically associated with successful particle integration into tissue or cell culture. Different disc strengths can be available for some gene gun models.

Related Research Articles

<span class="mw-page-title-main">Pump</span> Device that imparts energy to the fluids by mechanical action

A pump is a device that moves fluids, or sometimes slurries, by mechanical action, typically converted from electrical energy into hydraulic energy.

<span class="mw-page-title-main">Valve</span> Flow control device

A valve is a device or natural object that regulates, directs or controls the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. In an open valve, fluid flows in a direction from higher pressure to lower pressure. The word is derived from the Latin valva, the moving part of a door, in turn from volvere, to turn, roll.

<span class="mw-page-title-main">Safety valve</span> Device for releasing excess pressure in a system

A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds preset limits. Pilot-operated relief valves are a specialized type of pressure safety valve. A leak tight, lower cost, single emergency use option would be a rupture disk.

<span class="mw-page-title-main">Check valve</span> Flow control device

A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid to flow through it in only one direction.

<span class="mw-page-title-main">Pressure vessel</span> Vessel for pressurised gases or liquids

A pressure vessel is a container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.

<span class="mw-page-title-main">Boiling liquid expanding vapor explosion</span> Explosion of a vessel containing liquid above boiling point

A boiling liquid expanding vapor explosion is an explosion caused by the rupture of a vessel containing a pressurized liquid that has reached a temperature above its boiling point. Because the boiling point of a liquid rises with pressure, the contents of the pressurized vessel can remain a liquid as long as the vessel is intact. If the vessel's integrity is compromised, the loss of pressure drops the boiling point, which can cause the liquid to convert to a gas expanding rapidly. If the gas is combustible, as in the case with hydrocarbons and alcohols, further damage can be caused by the ensuing fire.

<span class="mw-page-title-main">Relief valve</span> Safety valve used to control or limit the pressure in a system

A relief valve or pressure relief valve (PRV) is a type of safety valve used to control or limit the pressure in a system; excessive pressure might otherwise build up and create a process upset, instrument or equipment failure, explosion, or fire.

<span class="mw-page-title-main">Gas cylinder</span> Cylindrical container for storing pressurised gas

A gas cylinder is a pressure vessel for storage and containment of gases at above atmospheric pressure. High-pressure gas cylinders are also called bottles. Inside the cylinder the stored contents may be in a state of compressed gas, vapor over liquid, supercritical fluid, or dissolved in a substrate material, depending on the physical characteristics of the contents. A typical gas cylinder design is elongated, standing upright on a flattened bottom end, with the valve and fitting at the top for connecting to the receiving apparatus.

<span class="mw-page-title-main">Boiler explosion</span> Catastrophic failure of a boiler

A boiler explosion is a catastrophic failure of a boiler. There are two types of boiler explosions. One type is a failure of the pressure parts of the steam and water sides. There can be many different causes, such as failure of the safety valve, corrosion of critical parts of the boiler, or low water level. Corrosion along the edges of lap joints was a common cause of early boiler explosions.

<span class="mw-page-title-main">Blowout preventer</span> Specialized valve

A blowout preventer (BOP) is a specialized valve or similar mechanical device, used to seal, control and monitor oil and gas wells to prevent blowouts, the uncontrolled release of crude oil or natural gas from a well. They are usually installed in stacks of other valves.

<span class="mw-page-title-main">Pilot-operated relief valve</span> Tank pressure control safety device

Like other pressure relief valves (PRV), pilot-operated relief valves (PORV) are used for emergency relief during overpressure events. PORV are also called pilot-operated safety valve (POSV), pilot-operated pressure relief valve (POPRV), or pilot-operated safety relief valve (POSRV), depending on the manufacturer and the application. Technically POPRV is the most generic term, but PORV is often used generically even though it should refer to valves in liquid service.

<span class="mw-page-title-main">Explosion vent</span>

An explosion vent or rupture panel is a safety device to protect equipment or buildings against excessive internal, explosion-incurred pressures, by means of pressure relief. An explosion vent will relieve pressure from the instant its opening pressure pstat has been exceeded.

Maximum Allowable Operating Pressure or MAOP is a pressure limit set, usually by a government body, which applies to compressed gas pressure vessels, pipelines, and storage tanks. For pipelines, this value is derived from Barlow's Formula, which takes into account wall thickness, diameter, allowable stress, and a safety factor.

<span class="mw-page-title-main">Potato cannon</span> Pipe-based cannon

A potato cannon is a pipe-based cannon that uses air pressure (pneumatic), or combustion of a flammable gas, to launch projectiles at high speeds. They are built to fire chunks of potato, as a hobby, or to fire other sorts of projectiles, for practical use. Projectiles or failing guns can be dangerous and result in life-threatening injuries, including cranial fractures, enucleation, and blindness if a person is hit.

A high-integrity pressure protection system (HIPPS) is a type of safety instrumented system (SIS) designed to prevent over-pressurization of a plant, such as a chemical plant or oil refinery. The HIPPS will shut off the source of the high pressure before the design pressure of the system is exceeded, thus preventing loss of containment through rupture (explosion) of a line or vessel. Therefore, a HIPPS is considered as a barrier between a high-pressure and a low-pressure section of an installation.

<span class="mw-page-title-main">Hydrogen safety</span> Procedures for safe production, handling and use of hydrogen

Hydrogen safety covers the safe production, handling and use of hydrogen, particularly hydrogen gas fuel and liquid hydrogen.

The Ship and Offshore Structural Mechanics Laboratory (SSML) is a laboratory in the Department of Naval Architecture and Ocean Engineering of Pusan National University. The SSML develops methods useful for strength analysis and structural design of marine structures. The methods developed should be helpful for achievement of high performance of the structural system. The Laboratory has the facilities for numerical and experimental studies. This includes mechanical testing equipment and high-speed computers with non-linear finite element programmes.

Surge control is the use of different techniques and equipment in a hydraulic system to prevent any excessive gain in pressure that would cause the hydraulic process pressure to exceed the maximum working pressure of the mechanical equipment used in the system.

<span class="mw-page-title-main">Instrumentation in petrochemical industries</span>

Instrumentation is used to monitor and control the process plant in the oil, gas and petrochemical industries. Instrumentation ensures that the plant operates within defined parameters to produce materials of consistent quality and within the required specifications. It also ensures that the plant is operated safely and acts to correct out of tolerance operation and to automatically shut down the plant to prevent hazardous conditions from occurring. Instrumentation comprises sensor elements, signal transmitters, controllers, indicators and alarms, actuated valves, logic circuits and operator interfaces.

<span class="mw-page-title-main">Cryogenic storage dewar</span> Vacuum insulated container

A cryogenic storage dewar is a specialised type of vacuum flask used for storing cryogens, whose boiling points are much lower than room temperature. It is named after inventor James Dewar, who developed it for his own work. They are commonly used in low-temperature physics and chemistry.

References

  1. US Patent 2,630,939
  2. "Bursting Disc Indicator". Continental Disc Corporation. CDC. Retrieved 15 July 2020.
  3. Nwaoha, Chikezie. Process Plant Equipment: Operation, Control, and Reliability (First ed.). y John Wiley & Sons, Inc. p. 665. doi:10.1002/9781118162569.app4.
  4. Hedlund, FH; Selig, RS; Kragh, EK (2016). "Large Steel Tank Fails and Rockets to Height of 30 meters - Rupture Disc Installed Incorrectly". Saf Health Work. 7 (2): 130–7. doi:10.1016/j.shaw.2015.11.004. PMC   4909846 . PMID   27340600.