A leak is a way (usually an opening) for fluid to escape a container or fluid -containing system, such as a tank or a ship's hull , through which the contents of the container can escape or outside matter can enter the container. Leaks are usually unintended and therefore undesired. The word leak usually refers to a gradual loss; a sudden loss is usually called a spill .
35-439: A leakage occurs when fluid is lost through a leak . Leakage may also refer to: Leak The matter leaking in or out can be gas , liquid , a highly viscous paste , or even a solid such as a powdered or granular solid or other solid particles. Sometimes the word " leak " is used in a figurative sense. For example, in a news leak secret information becomes public. According to ASTM D7053-17, water leakage
70-599: A leak. If submerging in water is not possible, then pressurization with air followed by covering the area to be tested with a soap solution is done to see if soap bubbles form, which indicate a leak. Other types of testing for gas leaks may involve testing for the outleaking gases with sensors which can detect that gas, for example - special sensing instruments for detecting natural gas. US federal safety law now requires natural gas companies to conduct testing for gas leaks upstream of their customer's gas meters. Where liquids are used, special color dyes may be added to help see
105-423: A plentiful supply of steam to spare. Steam engines and steam turbines use the expansion of steam to drive a piston or turbine to perform mechanical work . The ability to return condensed steam as water-liquid to the boiler at high pressure with relatively little expenditure of pumping power is important. Condensation of steam to water often occurs at the low-pressure end of a steam turbine, since this maximizes
140-594: A possible industrial location of a leak between two fluid systems includes a leak between the shell and tube sides in a heat exchanger , potentially contaminating either or both fluid systems with the other fluid. A system holding a full or partial vacuum may have a leak causing inleakage of air from the outside. Hazmat procedures and/or teams may become involved when leakage or spillage of hazardous materials occurs. Leaks while transporting hazardous materials could result in danger; for example, when accidents occur. However, even leakage of steam can be dangerous because of
175-454: A supply of steam stored on board in a large tank resembling a conventional locomotive's boiler. This tank was filled by process steam , as is available in many sorts of large factory, such as paper mills . The locomotive's propulsion used pistons and connecting rods, as for a typical steam locomotive. These locomotives were mostly used in places where there was a risk of fire from a boiler's firebox, but were also used in factories that simply had
210-566: Is damage to the water supply system or wastewater system on a property that causes a drip or flow to release. Gas leaks , e.g. in natural gas lines allow flammable and potentially explosive gas to leak out, resulting in a hazardous situation. Leaks of refrigerant may occur in refrigerators or air conditioning systems, large and small. Some industrial plants, especially chemical and power plants , have numerous fluid systems containing many types of liquid or gas chemicals, sometimes at high temperature and/or pressure . An example of
245-443: Is defined as the passage of (liquid) water through a material or system designed to prevent passage of water. Types of leak openings include a puncture, gash, rust or other corrosion hole, very tiny pinhole leak (possibly in imperfect welds ), crack or microcrack, or inadequate sealing between components or parts joined together. When there is a puncture, the size and shape of the leak can often be seen, but in many other cases,
280-467: Is heated further, the droplets evaporate, and at a high enough temperature (which depends on the pressure) all of the water evaporates and the system is in vapour–liquid equilibrium . When steam has reached this equilibrium point, it is referred to as saturated steam . Superheated steam or live steam is steam at a temperature higher than its boiling point for the pressure, which only occurs when all liquid water has evaporated or has been removed from
315-558: Is often referred to as "steam". When liquid water becomes steam, it increases in volume by 1,700 times at standard temperature and pressure ; this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines , which are a sub-group of steam engines. Piston type steam engines played a central role in the Industrial Revolution and modern steam turbines are used to generate more than 80 % of
350-547: Is part of the non-destructive test NDT portfolio that can be applied to a part to verify its conformity; depending on material, pressure, leak tightness specifications, different methods can be applied. International standards has been defined to assist in these choices. For example, BS EN 1779:1999; it applies to assessment of leak tightness by indication or measurement of gas leakage, but excludes hydrostatic, ultrasonic or electromagnetic methods. Other standards also apply: In shell and tube heat exchangers , Eddy current testing
385-414: Is sometimes done in the tubes to find locations on tubes where there may be leaks or damage which may eventually develop into a leak. In complex plants with multiple fluid systems, many interconnecting units holding fluids have isolation valves between them. If there is a leak in a unit, its isolation valves can be shut to "isolate" the unit from the rest of the plant. Leaks are often repaired by plugging
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#1732775462952420-673: Is sometimes pressure tested by filling with air and the pressure monitored to see if it drops, indicating a leak. A very commonly used test after new construction or repair is a hydrostatic test , sometimes called a pressure test. In a hydrostatic test, a system is pressurized with water to look for a drop in pressure or to see where it leaks out. Helium testing may be done to detect for any very small leakage such as when testing certain diaphragm or bellows valves, made for high purity and utra high purity service, requiring low leak rate capability. Helium and hydrogen have very small molecules which can go through very small leaks. Leak testing
455-429: Is used for soil sterilization to avoid the use of harmful chemical agents and increase soil health . Steam's capacity to transfer heat is also used in the home: for cooking vegetables, steam cleaning of fabric, carpets and flooring, and for heating buildings. In each case, water is heated in a boiler, and the steam carries the energy to a target object. Steam is also used in ironing clothes to add enough humidity with
490-494: Is used in various chemical processes as a reactant. Steam cracking of long chain hydrocarbons produces lower molecular weight hydrocarbons for fuel or other chemical applications. Steam reforming produces syngas or hydrogen . Used in cleaning of fibers and other materials, sometimes in preparation for painting. Steam is also useful in melting hardened grease and oil residues, so it is useful in cleaning kitchen floors and equipment and internal combustion engines and parts. Among
525-455: The air conditioning system. Some of these vehicle fluids have different colors to help identify the type of leaking fluid. Batteries are at risk of leakage, because their operation inherently involves chemical corrosion. A zinc-carbon battery is an example of a commonly-seen leaking component; the electrolytes inside the cell sometimes leak out of the cell casing and cause damage to an electronic appliance. Water leaks occur when there
560-575: The energy efficiency , but such wet-steam conditions must be limited to avoid excessive turbine blade erosion. Engineers use an idealised thermodynamic cycle , the Rankine cycle , to model the behaviour of steam engines. Steam turbines are often used in the production of electricity. An autoclave , which uses steam under pressure, is used in microbiology laboratories and similar environments for sterilization . Steam, especially dry (highly superheated) steam, may be used for antimicrobial cleaning even to
595-639: The electric generation cycle. The world's biggest steam generation system is the New York City steam system , which pumps steam into 100,000 buildings in Manhattan from seven co-generation plants. In other industrial applications steam is used for energy storage , which is introduced and extracted by heat transfer, usually through pipes. Steam is a capacious reservoir for thermal energy because of water's high heat of vaporization . Fireless steam locomotives were steam locomotives that operated from
630-419: The environment. For some frequently operating centrifugal pumps, such leakage is so expected that provisions are made for carrying away the leakage. Similarly, wearing out of seals or packing around piston-driven pumps could also develop into outleakage to the environment. The pressure difference between both sides of the leak can affect the movement of material through the leak. Fluids will commonly move from
665-416: The faucets. Cracks may result from either outright damage, or wearing out by stress such as fatigue failure or corrosion such as stress corrosion cracking . Wearing out of a surface between a disk and its seat in a valve could cause a leak between ports (valve inlets or outlets). Wearing out of packing around a turning valve stem or rotating centrifugal pump shaft could develop into fluid outleakage into
700-400: The fluid is a gas or liquid. Leaks in vehicle hydraulic systems such as brake or power steering lines could cause loss of brake or power steering fluid, resulting in failure of the brakes, power steering, or other hydraulic system. Also possible are leaks of engine coolant - particularly in the radiator and at the water pump seal, transmission fluid , motor oil , and refrigerant in
735-465: The heat to take wrinkles out and put intentional creases into the clothing. As of 2000 around 90% of all electricity was generated using steam as the working fluid , nearly all by steam turbines. In electric generation, steam is typically condensed at the end of its expansion cycle, and returned to the boiler for re-use. However, in co-generation , steam is piped into buildings through a district heating system to provide heat energy after its use in
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#1732775462952770-430: The heat transfer load. Steam Steam is water vapour ( water in the gas phase), often mixed with air and/or an aerosol of liquid water droplets. This may occur due to evaporation or due to boiling , where heat is applied until water reaches the enthalpy of vaporization . Steam that is saturated or superheated (water vapor) is invisible; however, wet steam, a visible mist or aerosol of water droplets,
805-481: The high temperature and energy of the steam. Leakage of air or other gas out of hot air balloons , dirigibles , or cabins of airplanes could present dangerous situations. A leak could even be inside a living body, such as a hole in the septum between heart ventricles causing an exchange of oxygenated and deoxygenated blood, or a fistula between bodily cavities such as between vagina and rectum . There can be numerous causes of leaks. Leaks can occur from
840-424: The higher pressure side to the lower pressure side. The larger the pressure difference, the more leakage there will typically be. The fluid pressures on both sides include the hydrostatic pressure , which is pressure due to the weight from the height of fluid level above the leak. When the pressures are about equal, there can be an exchange of fluids between both sides, or little to no net movement of fluid across
875-526: The leak. Containers, vessels, enclosures, or other fluid system are sometimes tested for leaks - to see if there is any leakage and to find where the leaks are so corrective action can be taken. There are several methods for leak testing , depending on the situation. Sometimes leakage of fluid may make a sound which can be detected. Tires, engine radiators, and maybe some other smaller vessels may be tested by pressurizing them with air and submerging them in water to see where air bubbles come out to indicate
910-415: The leakage rate, as in volume of fluid leaked per time, rather than the size of the opening. Common types of leaks for many people include leaks in vehicle tires, which allows air to leak out and results in flat tires , and leaks in containers, which spills the contents. Leaks can occur or develop in many different kinds of household, building, vehicle, marine, aircraft, or industrial fluid systems, whether
945-445: The leakage. Other detectable substances in one of the liquids may be tested, such as saline to find a leak in a sea water system, or detectable substances may even be deliberately added to test for leakage. Newly constructed, fabricated, or repaired systems or other vessels are sometimes tested to verify satisfactory production or repair. Plumbers often test for leaks after working on a water or other fluid system. A vessel or system
980-405: The leaking holes or using a patch to cover them. Leaking tires are often fixed this way. Leaking gaskets, seals, washers, or packing can be replaced. Use of welding, soldering, sealing, or gluing may be other ways to fix leaks. Sometimes, the most practical solution is to replace the leaking unit. Leaking water heaters are often replaced by home or building owners. If there is a leak in one of
1015-408: The levels of sterilization. Steam is a non-toxic antimicrobial agent. Steam is used in piping for utility lines. It is also used in jacketing and tracing of piping to maintain the uniform temperature in pipelines and vessels. Steam is used across multiple industries for its ability to transfer heat to drive chemical reactions, sterilize or disinfect objects and to maintain constant temperatures. In
1050-410: The lumber industry, steam is used in the process of wood bending , killing insects, and increasing plasticity. Steam is used to accentuate drying of concrete especially in prefabricates. Care should be taken since concrete produces heat during hydration and additional heat from the steam could be detrimental to hardening reaction processes of the concrete. In chemical and petrochemical industries , steam
1085-608: The outset even during construction or initial manufacture/assembly of fluid systems. Pipes , tubing , valves , fittings , or other components may be improperly joined or welded together. Components with threads may be improperly screwed together. Leaks can be caused by damage; for example, punctures or fracture. Often leaks are the result of deterioration of materials from wear or aging, such as rusting or other corrosion or decomposition of elastomers or similar polymer materials used as gaskets or other seals . For example, wearing out of faucet washers causes water to leak at
Leakage - Misplaced Pages Continue
1120-421: The size and shape of the leak opening may not be so obvious. In many cases, the location of a leak can be determined by seeing material drip out at a certain place, although the leak opening itself is not obvious. In some cases, it may be known or suspected there is a leak, but even the location of the leak is not known. Since leak openings are often irregular shapes or extended cracks, leaks are sometimes sized by
1155-472: The system. Steam tables contain thermodynamic data for water/saturated steam and are often used by engineers and scientists in design and operation of equipment where thermodynamic cycles involving steam are used. Additionally, thermodynamic phase diagrams for water/steam, such as a temperature-entropy diagram or a Mollier diagram shown in this article, may be useful. Steam charts are also used for analysing thermodynamic cycles. In agriculture , steam
1190-432: The tubes of a shell and tube heat exchanger , that tube can be plugged at both ends with specially sized plugs to isolate the leak. This is done in the plenum(s) at the points where the tube ends connect to the tubesheet(s). Sometimes a damaged but not yet leaking tube is pre-emptively plugged to prevent future leakage. The heat transfer capacity of that tube is lost, but there are usually plenty of other tubes to pick up
1225-403: The world's electricity. If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapour pressure , it can create a steam explosion . Steam is traditionally created by heating a boiler via burning coal and other fuels, but it is also possible to create steam with solar energy. Water vapour that includes water droplets is described as wet steam . As wet steam
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