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Check Valve
A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves are often part of common household items. Although they are available in a wide range of sizes and costs, check valves generally are very small, simple, and inexpensive. Check valves work automatically and most are not controlled by a person or any external control; accordingly, most do not have any valve handle or stem. The bodies (external shells) of most check valves are made of plastic or metal. An important concept in check valves is the cracking pressure which is the minimum differential upstream pressure between inlet and outlet at which the valve will operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Filter (respirator)
Mechanical filters, a part of particulate respirators, are a class of Air filter, filter for air-purifying respirators that mechanically stops particulates from reaching the wearer's nose and mouth. They come in multiple physical forms. Mechanism of operation Mechanical filter respirators retain particulate matter such as dust created during woodworking or metal processing, when contaminated air is passed through the filter material. Wool is still used today as a filter, along with plastic, glass, cellulose, and combinations of two or more of these materials. Since the filters cannot be cleaned and reused and have a limited lifespan, cost and disposability are key factors. Single-use, disposable and replaceable-cartridge models exist. Mechanical filters remove contaminants from air in the following ways: # by ''interception'' when particles following a line of flow in the airstream come within one radius of a fiber and adhere to it; # by ''impaction'', when larger particles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydronic Heating
Hydronics () is the use of liquid water or gaseous water (steam) or a water solution (usually glycol with water) as a heat-transfer medium in heating and cooling systems. The name differentiates such systems from oil and refrigerant systems. Historically, in large-scale commercial buildings such as high-rise and campus facilities, a hydronic system may include both a chilled and a heated water loop, to provide for both heating and air conditioning. Chillers and cooling towers are used either separately or together as means to provide water cooling, while boilers heat water. A recent innovation is the chiller boiler system, which provides an efficient form of HVAC for homes and smaller commercial spaces. District heating Many larger cities have a district heating system that provides, through underground piping, publicly available high temperature hot water and chilled water. A building in the service district may be connected to these on payment of a service fee. Types of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reed Valve
Reed valves are a type of check valve which restrict the flow of fluids to a single direction, opening and closing under changing pressure on each face. Modern versions often consist of flexible metal or composite materials (fiberglass or carbon fiber). Applications Traditional Reed valves, normally a leather flap covering a hole, are amongst the earliest form of automatic flow control for liquids and gases. They have been used for thousands of years in water pumps and for hundreds of years in bellows for high-temperature forges and musical instruments such as church organs and accordions. In nature, heart valves operate in a somewhat similar fashion. Pumps Reed valves are used in some reciprocating compressor designs, and in the pumping element of some musical instruments, large and small. Two-stroke engines Reed valves are commonly used in high-performance versions of the two-stroke engine, where they control the fuel-air mixture admitted to the cylinder. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duckbill Valve
A duckbill valve is a check valve, usually manufactured from rubber or synthetic elastomer, and has two or more flaps, usually shaped like the beak of a duck. It is commonly used in medical applications to prevent contamination due to backflow. One end of the valve is stretched over the outlet of a supply line, conforming itself to the shape of the line, usually round. The other end, the duckbill, retains its natural flattened shape. When a fluid is pumped through the supply line and therefore the duckbill, the flattened end opens to permit the pressurized fluid to pass. When pressure is removed, however, the duckbill end returns to its flattened shape, preventing backflow. The duckbill valve is similar in function to the mitral valve in the heart. See also Heimlich valve. A trifold form of this valve, known as a joker valve, is used in one popular marine toilet. Also known as a spear valve or flutter valve, this automatic device serves as a gas exhaust valve on the insi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butterfly Valve
A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing mechanism is a disk that rotates. Principle of operation Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves are generally favored because they cost less than other valve designs, and are lighter weight so they need less support. The disc is positioned in the center of the pipe. A rod passes through the disc to an actuator on the outside of the valve. Rotating the actuator turns the disc either parallel or perpendicular to the flow. Unlike a ball valve, the disc is always present within the flow, so it induces a pressure drop, even when open. A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is closed, the disc is turned so that it completely blocks off the passageway. Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
110327-F-PM645-011 Butterfly Check Valve
Eleven or 11 may refer to: *11 (number) * One of the years 11 BC, AD 11, 1911, 2011 Literature * ''Eleven'' (novel), a 2006 novel by British author David Llewellyn *''Eleven'', a 1970 collection of short stories by Patricia Highsmith *''Eleven'', a 2004 children's novel in The Winnie Years by Lauren Myracle *''Eleven'', a 2008 children's novel by Patricia Reilly Giff *''Eleven'', a short story by Sandra Cisneros Music *Eleven (band), an American rock band * Eleven: A Music Company, an Australian record label *Up to eleven, an idiom from popular culture, coined in the movie ''This Is Spinal Tap'' Albums * ''11'' (The Smithereens album), 1989 * ''11'' (Ua album), 1996 * ''11'' (Bryan Adams album), 2008 * ''11'' (Sault album), 2022 * ''Eleven'' (Harry Connick, Jr. album), 1992 * ''Eleven'' (22-Pistepirkko album), 1998 * ''Eleven'' (Sugarcult album), 1999 * ''Eleven'' (B'z album), 2000 * ''Eleven'' (Reamonn album), 2010 * ''Eleven'' (Martina McBride album), 2011 * ''Eleven'' (Mr Fog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backwater Valve
A backwater valve is a backflow prevention device used to prevent outbound water through a dwelling's drain pipes from re-entering -- " back flowing"—into a home. The valve contains a flap that allows water to exit the home, but closes to prevent the back flow into the home. Backwater valves commonly activate when a city's sewer lines are unable to handle a large amount of falling precipitation; this puts homes that are tied into the storm lines at risk of having water back flow into them. There is a big difference between backwater valves and backflow preventers: * A backwater valve prevents raw sewage from backing up into your home through your toilets, showers, etc. * A backflow preventer deals with protecting a potable water source from being contaminated by a reverse flow of foul water (ex: isolating your toilet's flush cistern and water supply from the toilet bowl water itself). See also * Check valve A check valve, non-return valve, reflux valve, retention valv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefighting
Firefighting is a profession aimed at controlling and extinguishing fire. A person who engages in firefighting is known as a firefighter or fireman. Firefighters typically undergo a high degree of technical training. This involves structural firefighting and wildland firefighting. Specialized training includes aircraft firefighting, shipboard firefighting, aerial firefighting, maritime firefighting, and proximity firefighting. Firefighting is a dangerous profession due to the toxic environment created by combustible materials, with major risks being smoke, oxygen deficiency, elevated temperatures, poisonous atmospheres, and violent air flows. To combat some of these risks, firefighters carry self-contained breathing apparatus. Additional hazards include falling (accident), falls – a constant peril while navigating unfamiliar layouts or confined spaces amid shifting debris under limited visibility – and structural collapse that can exacerbate the problems encountered in a toxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Hammer
Hydraulic shock ( colloquial: water hammer; fluid hammer) is a pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly: a momentum change. It is usually observed in a liquid but gases can also be affected. This phenomenon commonly occurs when a valve closes suddenly at an end of a pipeline system and a pressure wave propagates in the pipe. This pressure wave can cause major problems, from noise and vibration to pipe rupture or collapse. It is possible to reduce the effects of the water hammer pulses with accumulators, expansion tanks, surge tanks, blowoff valves, and other features. The effects can be avoided by ensuring that no valves will close too quickly with significant flow, but there are many situations that can cause the effect. Rough calculations can be made using the Zhukovsky (Joukowsky) equation, or more accurate ones using the method of characteristics. History In the 1st century B.C., Marcus Vitruvius Pollio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
