Permanent Magnet

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Magnet is a material that provides magnetic field. A magnetic field is invisible, however, responsible for most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.

permanent magnet is an object made from the material that is magnetized and creats its own persistent magnetic field. An every day example is a refrigerator magnet used to hold notes on the door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic. These include iron, nickel, cobalt, some alloys of rare earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.


Ferromagnetic materials can be divided into magnetically “soft” materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically hard materials, which do. Permanent magnets are made from “hard” ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a powerful magnetic field during manufacture, to align their internal microcrystalline structure, making them very hard to demagnetize. To demagnetize a saturated magnet, a certain magnetic field must be applied, and this threshold depends on cercivity of the respective material. “Hard” materials have high coercivity, whereas “soft” materials have low coercivity


The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces. The local strength of magnetism in material is measured by its magnetization.

The Steel Pipe Flange and Fittings in Plumbing System

       The steel pipe flange is widely used in the construction industry, but can also be found in a variety of manufacturing and industrial applications. In plumbing system, steel pipe can be used to transport liquids and gases for commercial and residential buildings, as well as in municipal water supplies. A flanged pipe is a type of pipe that has an area on the end that gives it a special function beyond a normal pipe. A flange may be inside or outside the pipe, and it usually allows the pipe to connect to a specific type of system. The flange makes the pipe thicker at the end and may make it wider as well, if the flange is on the outside. The chief reason to use a flanged pipe (steel pipe flange) is to make attaching and removing the pipe from the connected system easier.

Steel pipes

       The steel pipe was once the most popular choice for supply of water and flammable gases. It is still used in many homes and businesses to convey natural gas or propane fuel, and is a popular choice in fire sprinkler systems due to its high heat resistance. In commercial buildings, steel pipe is used to convey heating or cooling water to heat exchangers, air handlers, fan coil, variable air volume (VAV) devices, or other HVAC equipment. And the pipe fittings are the occupation of installing or repairing piping or tubing systems that convey liquid, gas, and occasionally solid materials. This work involves selecting and preparing pipe or tubing, joining it together by various means, and the location and repair of leaks.

       Fitters work with a variety of pipe and tubing materials including several types of steel, copper, iron, aluminum, and plastic. Pipe fitting is not plumbing; the two are related but separate trades. Materials, techniques, and usages vary from country to country as different nations have different standards to install pipe.