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In automatic control, a regulator is a device which has the function of maintaining a designated characteristic. It performs the activity of managing or maintaining a range of values in a machine. The measurable property of a device is managed closely by specified conditions or an advance set value; or it can be a variable according to a predetermined arrangement scheme. It can be used generally to connote any set of various controls or devices for regulating or controlling items or objects. Regulators can be designed to control anything from gases or fluids, to light or electricity. Speed can be regulated by electronic, mechanical, or electro-mechanical means. Such instances include: Electronic regulators as used in modern railway sets where the voltage is raised or lowered to control the speed of the engine; Mechanical systems such as valves as used in fluid control systems. Purely mechanical pre-automotive systems included such designs as the Watt centrifugal governor whereas modern systems may have electronic fluid speed sensing components directing solenoids to set the valve to the desired rate.

Designed in 1835, the gas regulator’s concept is easy, and its impact has been long-lasting. There are various types of regulators, but their function is the same: to use a valve system to control natural gas or propane pressure or other gas flow. Common appliances that use regulators include gas stoves, propane grills, or oxy-fuel bottles for welding. Each type of regulator’s components consists of a set spring attached to a rod that runs down from a set screw through a diaphragm into the valve. There are three primary operating components working together to regulate the pressure within the valve. The loading mechanism determines the delivery pressure. Most often, it is a spring. The sensing element, or diaphragm, senses the force against the spring. Finally, the control element accomplishes the reduction of the inlet pressure through to the outlet pressure. Gas enters the regulator’s chamber, putting pressure on the diaphragm. The diaphragm then moves upward as controlled by the set spring. This allows a specific flow of fuel from the source to the appliance or device. Adjusting the control knob determines the rate of flow and the pressure. Turning clockwise will push the diaphragm down and allow more gas to come into the valve. Turn counter-clockwise to reduce the amount of fuel and pressure.

Liquefied petroleum gas (LPG, LP gas, or condensate) is a fuel gas made of petrol which contains a flammable mixture of hydrocarbon gases, most commonly propane, butane, and propylene. However, the latter two typically compose 5% or less of the mixture. LPG is used as a fuel gas in heating appliances, cooking equipment, and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel, it is often referred to as autogas. Varieties of LPG that are bought and sold include mixes that are mostly propane (C3H8), mostly butane (C4H10), and, most commonly, mixes including both propane and butane. In the northern hemisphere winter, the mixes contain more propane, while in summer, they contain more butane. In the United States, mainly two grades of LPG are sold: commercial propane and HD-5. These specifications are published by the Gas Processors Association (GPA) and the American Society of Testing and Materials. Propane/butane blends are also listed in these specifications. Propylene, butylenes and various other hydrocarbons are usually also present in small concentrations such as C2H6, CH4, and C3H8. HD-5 limits the amount of propylene that can be placed in LPG to 5% and is utilized as an autogas specification. A powerful odorant, ethanethiol, is added so that leaks can be detected easily. The internationally recognized European Standard is EN 589. In the United States, tetrahydrothiophene (thiophane) or amyl mercaptan are also approved odorants, although neither is currently being utilized. An LPG regulator is a device that maintains a stable downstream pressure regardless of changes in gas flow and upstream pressure. Among them, the LPG jumbo regulator and the LPG quick-on regulator are typical representatives.

A hose is a flexible hollow tube designed to carry fluids from one location to another. Hoses are also sometimes called pipes (the word pipe usually refers to a rigid tube, whereas a hose is usually a flexible one), or more generally tubing. The shape of a hose is usually cylindrical (having a circular cross section). Hose design is based on a combination of application and performance. Common factors are size, pressure rating, weight, length, straight hose or coilhose, and chemical compatibility. Applications mostly use nylon, polyurethane, polyethylene, PVC, or synthetic or natural rubbers, based on the environment and pressure rating needed. In recent years, hoses can also be manufactured from special grades of polyethylene (LDPE and especially LLDPE). Other hose materials include PTFE (Teflon), stainless steel, and other metals. Dredge rubber hoses have a long story, which features high strength and flexibility. A flexible dredging hose widely used in dredgers to convey silt or gravel. It is resistant to abrasion and wear to ensure long service life. Types of flexible dredge hose include the floating rubber hose, discharge hose, suction hose, armored hose and ceramic hose. To achieve a better pressure resistance, hoses can be reinforced with fibers or a steel cord. Commonly used reinforcement methods are braiding, spiraling, knitting and wrapping of fabric plies. The reinforcement increases the pressure resistance but also the stiffness. To obtain flexibility, corrugations or bellows are used. Usually these corrugated internal or helical reinforcement rings are applied to maintain these corrugated or bellowed structures under pressure.

The gas hose includes a pipe joint, the pipe joint is composed of a pipe body and a steel sleeve fastened to one end of the pipe body, the pipe body has a through hole, and the one end of the pipe body is formed with a an annular coupling groove into which the hose is inserted, the axial depth of the annular coupling groove is greater than the length of the steel sleeve, and a part of the inner surface of the annular coupling groove is a tapered surface, a step is formed where the inner end of the tapered surface abuts another part of the inner surface of the annular coupling groove. The structure avoids the phenomenon that when the pipe joint is matched with the hose, the hose is inserted too deeply into the pipe joint, which causes deformation of the end of the pipe joint, which is beneficial to the smooth flow of gas and has high safety. A circular arc transition is adopted at the junction between the outer surface and the inner surface of the annular coupling groove to prevent stress concentration.

A gas stove is a stove that is fuelled by combustible gas such as syngas, natural gas, propane, butane, liquefied petroleum gas or other flammable gas. Before the advent of gas, cooking stoves relied on solid fuels such as coal or wood. The first gas stoves were developed in the 1820s and a gas stove factory was established in England in 1836. This new cooking technology had the advantage of being easily adjustable and could be turned off when not in use. The gas stove, however, did not become a commercial success until the 1880s, by which time supplies of piped gas were available in cities and large towns in Britain. The stoves became widespread on the European Continent and in the United States in the early 20th century. Gas stoves became more common when the oven was integrated into the base and the size was reduced to better fit in with the rest of the kitchen furniture. By the 1910s, producers started to enamel their gas stoves for easier cleaning. Ignition of the gas was originally by match and this was followed by the more convenient pilot light. This had the disadvantage of continually consuming gas. The oven still needed to be lit by match and accidentally turning on the gas without igniting it could lead to an explosion. To prevent these types of accidents, oven manufacturers developed and installed a safety valve called a flame failure device for gas hobs (cooktops) and ovens. Most modern gas stoves have electronic ignition, automatic timers for the oven and extractor hoods to remove fumes. Gas stoves are a significant source of indoor air pollution, and require good ventilation to maintain acceptable air quality.

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