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Explosion Vent
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 (or activation) pressure ''p''stat has been exceeded. Several explosion vent panels can be installed on the same process vessel to be protected. Explosion vents are available in the versions ''self-destructive, non-self-re-closing'' and ''re-usable, self-re-closing''. Explosion vent construction must balance the contradictory requirements "low inertia" and "high strength". Inertia negatively affects an explosion vent's efficiency. High strength is required to endure the considerable forces that move the vent's venting element in order to open the venting orifice. Unintended disintegration must not cause disintegrating parts turning into a missile. The evaluation of an explosion vent's efficiency and its range of application are subje ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rupture Disc
A rupture disk, 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. A rupture disk 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. The membrane is usually made out of metal, but nearly any material (or different materials in layers) can be used to suit a particular application. Rupture disks provide instant response (within milliseconds or microseconds in very small sizes) to an increase or decrease in system pressure, but once the disk has ruptured it will not reseal. Major advantages of the application of rupture disks compared to using pressure relief valves include leak-tightness, cost, response time, size constraints, and ease of maintenance. Rupture disks a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prestressed Structure
In structural engineering, a prestressed structure is a load-bearing structure whose overall integrity, stability and security depend, primarily, on ''prestressing'': the intentional creation of permanent stresses in the structure for the purpose of improving its performance under various service conditions. The basic types of prestressing are: *Precompression with mostly the structure's own weight *Pre-tensioning with high-strength embedded tendons *Post-tensioning with high-strength bonded or unbonded tendons Today, the concept of a prestressed structure is widely employed in the design of buildings, underground structures, TV towers, power stations, floating storage and offshore facilities, nuclear reactor vessels, and numerous bridge systems. It is especially prominent in construction using concrete (see pre-stressed concrete). The idea of precompression was apparently familiar to ancient Roman architects. The tall attic wall of the Colosseum The Colosseum ( ; it, Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as of this. Manometric u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Relief Valve
A relief valve or pressure relief valve (PRV) is a type of safety valve used to control or limit the pressure in a system; pressure might otherwise build up and create a process upset, instrument or equipment failure, or fire. The pressure is relieved by allowing the pressurized fluid to flow from an auxiliary passage out of the system. The relief valve is designed or set to open at a predetermined set pressure to protect pressure vessels and other equipment from being subjected to pressures that exceed their design limits. When the set pressure is exceeded, the relief valve becomes the "path of least resistance" as the valve is forced open and a portion of the fluid is diverted through the auxiliary route. In systems containing flammable fluids, the diverted fluid (liquid, gas or liquid-gas mixture) is either recaptured by a low pressure, high-flow vapor recovery system or is routed through a piping system known as a ''flare header'' or ''relief header'' to a central, elevated ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inert Gas
An inert gas is a gas that does not readily undergo chemical reactions with other chemical substances and therefore does not readily form chemical compounds. The noble gases often do not react with many substances and were historically referred to as the inert gases. Inert gases are used generally to avoid unwanted chemical reactions degrading a sample. These undesirable chemical reactions are often oxidation and hydrolysis reactions with the oxygen and moisture in air. The term ''inert gas'' is context-dependent because several of the noble gases can be made to react under certain conditions. Purified argon gas is the most commonly used inert gas due to its high natural abundance (78.3% N2, 1% Ar in air) and low relative cost. Unlike noble gases, an inert gas is not necessarily elemental and is often a compound gas. Like the noble gases, the tendency for non-reactivity is due to the valence, the outermost electron shell, being complete in all the inert gases. This is a tendency, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosives Safety
Explosives safety originated as a formal program in the United States in the aftermath of World War I when several ammunition storage areas were destroyed in a series of mishaps. The most serious occurred at Picatinny Arsenal Ammunition Storage Depot, New Jersey, in July, 1926 when an electrical storm led to fires that caused explosions and widespread destruction. The severe property damage and 19 fatalities led Congress to empower a board of Army and Naval officers to investigate the Picatinny Arsenal disaster and determine if similar conditions existed at other ammunition depots. The board reported in its findings that this mishap could recur, prompting Congress to establish a permanent board of colonels to develop explosives safety standards and ensure compliance beginning in 1928. This organization evolved into the Department of Defense Explosives Safety Board (DDESB) and is chartered in Title 10 of the US Code. The DDESB authors Defense Explosives Safety Regulation (DESR) 605 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosion Protection
Explosion protection is used to protect all sorts of buildings and civil engineering infrastructure against internal and external explosions or deflagrations. It was widely believed until recently that a building subject to an explosive attack had a chance to remain standing only if it possessed some extraordinary resistive capacity. This belief rested on the assumption that the specific impulse or the time integral of pressure, which is a dominant characteristic of the blast load, is fully beyond control. Techniques Avoidance Avoidance makes it impossible for an explosion or deflagration to occur, for instance by means of suppressing the heat and the pressure needed for an explosion using an aluminum mesh structure such as eXess, by means of consistent displacement of the O2 necessary for an explosion or deflagration to take place, by means of padding gas (f. i. CO2 or N2), or, by means of keeping the concentration of flammable content of an atmosphere consistently below or abov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dust Explosion
A dust explosion is the rapid combustion of fine particles suspended in the air within an enclosed location. Dust explosions can occur where any dispersed powdered combustible material is present in high-enough concentrations in the atmosphere or other oxidizing gaseous medium, such as pure oxygen. In cases when fuel plays the role of a combustible material, the explosion is known as a fuel-air explosion. Dust explosions are a frequent hazard in coal mines, grain elevators, and other industrial environments. They are also commonly used by special effects artists, filmmakers, and pyrotechnicians, given their spectacular appearance and ability to be safely contained under certain carefully controlled conditions. Thermobaric weapons exploit this principle by rapidly saturating an area with an easily combustible material and then igniting it to produce explosive force. These weapons are the most powerful non-nuclear weapons in existence. Terminology If rapid combustion occurs in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as of this. Manometric u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blast Damper
A blast damper is used to protect occupants and equipment of a structure against overpressures resultant of an explosion. The blast dampers normally protect air inlets and exhaust penetrations in an otherwise hardened structure. Blast dampers are related or identical to blast valves, the latter name is generally used to describe blast mitigation devices as they relate to nuclear explosions. Operation Blast dampers usually employ some type of blade held open with tension from a spring. The damper blades close automatically when pressure overcomes the resistance offered by the spring. Various models differ in the amount of blast protection (e.g. 1 bar/14.5 psi or lower amounts of protection) and whether they stay closed after the blast or remain functional. Design Typical blast dampers are sized to match HVAC ductwork and provide proper airflow with low pressure drop. Common applications include protecting equipment and personnel of control rooms and accommodation modules in petroc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
