A leakage is a (usually opening) method for liquids to exit from a container or liquid-containing system, such as a tank or hull, through which the contents of the container may pass or the material outside can enter the container. Leaks are usually unintentional and therefore undesirable. The word leak usually refers to a gradual loss; A sudden loss is usually called spill .
Materials that leak in or out may be gaseous, liquid, highly viscous paste, or even solid as powder or solid granules or other solid particles.
Sometimes the word " is leaked " is used in a figurative sense. For example, in the secret information the news leakage becomes public.
Video Leak
Type and possible cause
Types of leak openings include punctures, wounds, rust or other corrosion holes, very small pinhole leaks (possibly in incomplete welds), cracks or microcracks, or inadequate sealing between components or unified parts. When there is a puncture, the size and shape of the leak is often visible, but in many other cases, the size and shape of the leaking openings may not be so obvious. In many cases, the location of the leak can be determined by looking at the material dripping in certain places, even though the leak opening itself is unclear. In some cases, it may be known or suspected there is a leak, but even the location of the leak is unknown. Because leaky openings are often irregular, leaks are sometimes measured by leakage rates, such as the volume of leaking fluid per time, not the size of the openings.
Common leakage types for many people include leaking vehicle tires, causing air to leak so that a flat tire, and leakage in a container, spilling its contents. Leaks can occur or develop in different types of households, buildings, vehicles, marine, aircraft, or industrial fluid systems, whether the fluid is a gas or liquid. Leaks in vehicle hydraulic systems such as brakes or power steering can cause brake fluid or power steering fluid resulting in brake failure, power steering, or other hydraulic systems. Also possible leakage of the engine coolant - especially in the radiator and in the water pump seal, transmission fluid, motor oil, and refrigerant in the air conditioning system. Some of these vehicle fluids have different colors to help identify leaky types of liquids. The zinc-carbon battery is an example of a leaky system; The electrolyte inside the cell sometimes leaks out of the cell casing and causes damage to the electronic device.
Water supply systems or wastewater systems in other homes or buildings may have leaks in many locations, causing water to go out or spills. Gas leaks, for example in natural gas lanes allow flammable and potentially explosive gas to leak out, resulting in a dangerous situation. Refrigerant leaks can occur in refrigerators or air conditioning systems, large and small. Some industrial plants, especially chemical and power plants, have many liquid systems containing many types of liquid or gas chemicals, sometimes at high temperatures and/or pressures. Examples of industrial sites may leak between two fluid systems including leakage between the shell side and the tube in a heat exchanger, potentially contaminating one or both fluid systems with other liquids. A system that holds a full or partial vacuum may have a leak that causes air leaks from outside. Hazmat's procedures and/team may become involved when leaks or spills of hazardous materials occur. Leakage when transporting hazardous materials can cause harm; for example, when an accident occurs. However, even steam leakage can be dangerous due to high temperature and steam energy.
Air leaks or other gas from hot air balloons, dirigibles, or airplane cabins may present dangerous situations. Leaks can even be in the body, such as a hole in the septum between the heart's ventricles that causes oxygenated and deoxygenated blood exchange, or fistula between the body cavities such as between the vagina and rectum.
There are many causes of leakage. Leakage can occur from the beginning even during construction or initial manufacture/assembly of fluid systems. Pipes, tubes, valves, fittings, or other components may be incorporated or welded together improperly. Components with threads can be tightened incorrectly. Leakage can be caused by damage; for example, puncture or fracture. Often leaks are the result of damage to materials from wear or aging, such as rust or corrosion or decomposition of elastomers or similar polymeric materials used as gaskets or other seals. For example, the use of a faucet washer causes water to leak in the faucet. Cracks can be produced from direct damage, or run out due to stress such as fatigue failure or corrosion such as tense crack corrosion. Wearing the surface between the dish and its seat on the valve can cause leakage between ports (valve or outlet holes). Wearing out of packing around the back valve rod or rotating centrifugal pump shaft can develop into a fluid outflow to the environment. For some frequent centrifugal pumps, such leaks are desirable so that provisions are made to carry leaks. Similarly, the use of seals or packing around the pump driven piston can also develop into an outleakage into the environment.
The pressure difference between the two sides of the leak can affect the movement of the material through leakage. The liquid will usually move from the higher pressure side to the lower pressure side. The bigger the pressure difference, the more leaks that occur. Fluid pressure on both sides includes hydrostatic pressure, which is the pressure due to the weight of the fluid level height above the leak. When the pressure is almost the same, there can be fluid exchange between the two sides, or little or no net movement of fluid throughout the leak.
Maps Leak
Test
Containers, ships, enclosures, or other liquid systems are sometimes tested for leaks - to see if there are any leaks and to locate where leaks are so that corrective action can be taken. There are several methods for testing leakage, depending on the situation. Sometimes a fluid leak can make a detectable sound. Tires, engine radiators, and possibly some other small vessels may be tested by pressing them with air and soaking them in water to see where the air bubbles come out to indicate a leak. If immersion in water is not possible, then pressurized with air followed by closing the area to be tested with soap solution is done to see if the soap bubbles are formed, indicating leakage. Other types of testing for gas leaks may involve testing for exit gas with sensors that can detect such gases, for example - special sensing instruments for detecting natural gas. The US federal safety law now requires natural gas companies to conduct gas leak testing upstream of their customers' gas meters. Where fluids are used, special color dyes can be added to help see leaks. Other substances that can be detected in any of the liquids can be tested, such as salt to locate leaks in seawater systems, or detectable substances that may even be intentionally added to test leaks.
Newly built, manufactured, or repaired systems or other vessels are sometimes tested to verify satisfactory production or repairs. Plumbers often test leaks after working on water or other liquid systems. A ship or system is sometimes tested for pressure by filling with air and monitored pressure to see if it falls, signaling a leak. A very common test used after construction or new repair is a hydrostatic test, sometimes called a pressure test. In a hydrostatic test, a system is pressed with water to look for pressure drops or to see where it leaks. Helium testing can be performed to detect very small leaks such as when testing certain diaphragm valves or valve bellows, which are made for high purity and high purity utra, requiring a low leakage capability. Helium and hydrogen have very small molecules that can pass through very small leaks.
Leak testing is part of a non-destructive NDT test portfolio that can be applied to the section to verify compliance; depending on the material, pressure, leak specification specifications, different methods can be applied. International standards have been established to assist in these choices. For example, BS EN 1779: 1999; it applies to the assessment of leakage of leaks by indication or measurement of gas leakage, but excludes hydrostatic, ultrasonic or electromagnetic methods. Other standards also apply:
- BS EN 13184: 2001 Non-destructive test. Leak test. Pressure change process
- BS EN 13185: 2001 Non-destructive test. Leak test. Tracking gas method
- BS EN 13192: 2002 Testing is not destructive. Leak test. Reference leak calibration for gas
In shell and tube heat exchangers, Eddy's current testing is sometimes done inside the tube to locate the tube where there may be a leak or damage that may eventually develop into a leak.
Corrective action
In complex plants with dual fluid systems, many interconnected units hold the fluid having an isolation valve between the two. If there is a leak in the unit, the isolation valve can be closed to "isolate" the unit from the rest of the plant.
Leakage is often fixed by inserting a leaking hole or using a patch to close it. Leaky tires are often fixed in this way. Leaky gaskets, seals, washing machines, or packing can be replaced. Use of welding, soldering, sealing, or gluing may be another way to fix leakage. Sometimes, the most practical solution is to replace the leaking unit. Leaking water heaters are often replaced by homeowners or buildings.
If there is a leak in one of the shell and tube heat exchanger tubes, the tube can be installed at both ends with a specially sized plug to isolate the leak. This is done in plenary (s) at the points where the tube end is connected to the tubesheet (s). Sometimes damaged but not leaked tubes are pre-emptively installed to prevent future leakage. The heat transfer capacity of the tube is gone, but there are usually many other tubes to take the heat transfer load.
See also
- Explosion
- Fugitive emissions
- Seals (mechanics)
References
Source of the article : Wikipedia
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