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Dry chemical powder is used on all classes of fires. Dry chemical powder puts out the fire by coating the burning material with a thin layer of dust, thereby separating the fuel from the oxygen in the air. The powder also works to interrupt the chemical reaction of fire, so these extinguishers are extremely effective at putting out the fire.
The carbon equivalent is a measure of the tendency of the weld to form martensite on cooling and to suffer brittle fracture. When the carbon equivalent is between 0.40 and 0.60 weld preheat may be necessary. When the carbon equivalent is above 0.60, preheat is necessary, postheat may be necessary. The following carbon equivalent formula is used ...
Carbon tetrachloride was the first chlorinated solvent to be used in dry-cleaning and was used until the 1950s. [45] It had the downsides of being corrosive to the dry-cleaning equipment and causing illness among dry-cleaning operators, and was replaced by trichloroethylene, tetrachloroethylene [45] and methyl chloroform (trichloroethane). [46]
Infobox references. Potassium chloride ( KCl, or potassium salt) is a metal halide salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water, and its solutions have a salt -like taste.
Chlorine dioxide is a chemical compound with the formula ClO 2 that exists as yellowish-green gas above 11 °C, a reddish-brown liquid between 11 °C and −59 °C, and as bright orange crystals below −59 °C. It is usually handled as an aqueous solution. It is commonly used as a bleach.
Tetrachloroethylene, also known as perchloroethylene [a] or under the systematic name tetrachloroethene, and abbreviations such as perc (or PERC), and PCE, is a chlorocarbon with the formula Cl 2 C=CCl 2. It is a non-flammable, stable, colorless and heavy liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning ...
Vertex distance is the distance between the back surface of a corrective lens, i.e. glasses (spectacles) or contact lenses, and the front of the cornea. Increasing or decreasing the vertex distance changes the optical properties of the system, by moving the focal point forward or backward, effectively changing the power of the lens relative to ...
Fire extinguisher. A stored-pressure fire extinguisher. A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which has reached the ceiling, endangers the user (i ...