In this way, a big fire accident can be prevented to take place and also protects the boiler from damage. In this video we look at the fusible plug, its construction, how it works and why we use them. All of the boiler fittings discussed are important and must be operated and maintained properly to operate a boiler safely. Boiler design is the process of designing boilers used for various purposes. Fireside fusible plug model 28403 conforms to asme standards, with maximum pressure of 250 lbs.
Below is a typical steam boiler diagram for dummys to understand with name of each component or boiler part. Fireactivated fusible plugs are filled with pure tin and feature a melting point between 445f and 450f. Fusible plugs are sometimes used on fire tube boilers to provide added. Packaged boiler is the most common and efficient type of fire tube boiler used in industry to produce steam and hot water. It is important that the boiler records and plug diagram see item7 above detail which form is in use on a boiler and that the fusible plugs and any spares are appropriately marked. This boiler generates lowpressure steam and it is a natural circulation boiler. The sketch is sufficiently explanatory, at least as to the dimensions of the parts. When the temperature of the combustion chamber crosses the permissible level, the fusible plug melts and the water through the combustion chamber enters into the furnace of the boiler and stops the fire. There are two types of fusible plugs, fireactuated and steamactuated. Cochran boiler main parts, working, advantages and. For example steam boiler, combi boiler, vaillant boiler, hot water boiler, gas boiler, electric boiler, weil mclain boiler, condensing boiler. The fusible plug consists of two hollow guns and one conical plug shown as figure. It is a threaded metallic cylindrical object, with a tapered hole in it which goes through its entire length. The fusible plug is a piece of metal or alloy stopping an aperture in some part of the boiler which is directly exposed to the fire, and of such a composition as to melt at a temperature lower than that at which the pressure of the steam would become dangerous.
Fire tube boiler operation pdf free fire tube boiler operation pdf free 19d25c4272 a,vertical. Vertical fire tube boilers could, but did not always, have a fusible plug installed partway down a larger, heavier gauge fire tube fitted especially for that purpose. A fusible plug is a threaded metal cylinder usually of bronze, brass or gunmetal, with a tapered hole drilled completely through its length. This is a long horizontal cylinder with a single large flue containing the fire. The initial use of the fusible plug was as a safety precaution against low water levels in steam engine boilers, but later applications.
The location chosen depends upon the boiler design. Fusible plug boiler mountings mechanical engineering. It may be of a two, three or four pass arrangement depicted by the number of tube passes within one common shell. A water tube boiler can be defined as a steam boiler in which the flow of water in the tubes, as well as hot gases, enclose the tubes. Mostly used boiler in small and medium industries with different fuels and steam pressure requirements. It is one of the two major types of boilers, the other being the watertube boiler. Apr 10, 2018 fusible plug is a small device installed in small horizontal fire tube boilers between furnaceburner, usually natural gas fired or oil fired and boiler water drum. In a smoke tube steam boiler, it is fitted on the front tube sheet, just above the tubes used. Hello sir agar fire tube boiler 1 ton ka ho fuel used wood 1 hours me kitne steam bnayega kg hr plzz reply. Now coming back to the main subject, the length of the fusible plug is run by a tapered hole. In steam engines the fusible plug is screwed into the crown sheet the top plate of the firebox, typically extending about an inch 25mm into the water space above it. The fusible boiler plug in its usual form consists of a brass or bronze casing with.
A boiler in which the water flows through the tubes which are during the normal boiler operation, the fusible plug is covered by water and. In certain circumstances, however, a plug of mild steel, a little larger than the fusible plug, and made as shown in the accompanying sketch, will be found as cheap, and quite as effective. The main requirement of this boiler is that it should produce steam at a very high rate. Nov 20, 2019 when the temperature of the combustion chamber crosses the permissible level, the fusible plug melts and the water through the combustion chamber enters into the furnace of the boiler and stops the fire. Dec 11, 2017 fire tube boilers are useful for small demands of steam and water tube boilers are useful for industrial level usage. This hole is closed or sealed by a tiny cone plug that is held by an easilyfusible metal, such as tin or lead. Boiler design basic steps boiler and mechanical power.
Main function of fusible plug in boiler thermodyne. Its object is to put off the fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit and avoids the explosion which may takes place due to overheating of the furnace. Its working depends upon the water level in the boiler shell. Fusible plugs may be located on the front sheet, rear sheet or crown sheet of the boiler. A fusible plug is a threaded metal cylinder usually of bronze, brass or gunmetal, with a tapered. Boiler room log books, fusible plugs and accessories boiler. What is the melting point of a fireactuated fusible plug filled with an alloy of tin, copper, and. Lancashire boiler is a horizontal type and stationary fire tube boiler. Fire activated fusible plugs are filled with pure tin and feature a melting point between 445f and 450f. Misra boilers pvt ltd offering fusible plug for boiler safety. The eutectic alloy plug has a specific melting point see table on other side. Fire tube boiler fusible plugs are installed 1 to 2 inches above the highest row of tubes. Locomotive and scotch marine boiler fusible plugs were almost universally accessible from the fire side. This type of plug can be replaced by closing the valve in the piping.
Therefore, this boiler requires a large amount of heating surface and large grate area to burn coal at a rapid rate. This design allows for air to enter and escape during filling and draining of the boiler. This boiler was invented in the year 1844, by william fairbairn. A hollow gun metal body is screwed to the fire box crown plate of boiler. Steam boiler diagram with parts for dummys electrical. Boiler room log books, fusible plugs and accessories. Boiler mounting fusible plug anuniverse 22 youtube. Fusible plug is a small device installed in small horizontal fire tube boilers between furnaceburner, usually natural gas fired or oil fired and boiler water drum for. Steam produced can be used for a variety of purposes including space heating, sterilization, drying, humidification and power generation. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating the water and ultimately creating steam. A fire tube boiler is a type of boiler in which hot gases pass from a fire through one or many more tubes running through a sealed container of water. Fig 8 national waterside fusible plug 10 items traditional fig 19 motor waggon fusible plug 2 items fusible plugs for model engines 3 items washout plugs 6 items br standard washout plugs 8 items oversize tap rental 2 items.
As a standard, johnston builds these vessels with control connections on both sides. P manufacturer india, fire tube boilers exporter india, fire tube boilers manufacturer india, multi dust collector exporter india, multi dust collector manufacturer india, oilgaselectric fired boilers exporter india, oilgas. A fusible plug operates as a safety valve when dangerous temperatures, rather than dangerous pressures, are reached in a closed vessel. A firetube boiler is a type of boiler in which hot gases from a fire pass through one or many more tubes running through a sealed container of water. This hole is sealed with a metal of low melting point that flows away if a predetermined, high temperature is reached. It is fitted on the fire box crown plate or over the combustion chamber at. A firetube boiler is sometimes called a smoketube boiler or shell boiler or sometimes just fire pipe.
Fusible plugs should be renewed regularly once a year. Fire tube boiler operation pdf free fun aim and ignite. Fusible plug corrosion resistant construction and available in brass or stainless steel underwriters laboratories listed and approved as fusible plugs, refrigerant globe recommends where fusible plugs are installed in an atmosphere which can cause stressstrains or corrosion of surfaces, the plugs be examined annually and replaced if evidence. B, for applications more than 420 to 480 deg c it shall be asme. Boiler tubes carry water, steam, or flue gases through the boiler. Another hollow gun metal is screwed to the first body.
To cut short the main purpose of boiler is to boil a liquid mostly the water in order to generate the steam for serving the purpose of heating a building or running an equipment through pressurized steam or pressurized water. A safety valve try lever test is performed with the boiler at 15 psi or higher. Jan 09, 2020 lancashire boiler is a horizontal type and stationary fire tube boiler. The temperature or condition of steam required for these applications is different, so how to design a boiler. They are constructed of bronze or braided with a tapered hole drilled lengthwise through the plug and filled with a lowmelting alloy consisting mostly of tin. Series pneumatic spring return actuator with a fusible plug. Fusible plug is a small device installed in small horizontal fire tube boilers between furnaceburner, usually natural gas fired or oil fired and boiler water drum. Typical locations for fusible plugs include the crown sheet top of combustion chamber, rear tube sheet scotch marine boiler and front tube sheet firebox boiler. Today we are discussed about the top 50 boiler information booster question answers these question is very helpful for those who worked in power plant as a boiler first class, boiler operator, boiler fireman, boiler operation engineering, energy manager or as a energy auditor these question answers are selected by the well. A fire tube boiler can be either horizontal or vertical. This is a vertical, fire tube boiler commonly used for small capacity steam generation.
The video focuses on fusible plugs used in compressed air and steam boiler systems. This hole is closed or sealed by a tiny cone plug that is held by an easily fusible metal, such as tin or lead. Economiser, fusible plug for boiler safety water tube boilers fire tube boilers water cum smoke tube boilers small industrial boilers vertical i. In fire tube boilers it may be there and material will be lead less melting point than steel boiler pressure parts shall confirm upto 420 deg c in carbon steel confirming to asme a106 gr. Fire tube boiler operation pdf free fun aim and ignite full. It is not necessary to take the boiler out of service to replace the plug. The fusible plug melts if the external temperature reaches f c, relieving pressure in the. Fusible plug for boiler safety home about us awards.
Swagelok fusible plug pdf stainless steel plug for 14 in. Not like fire tube boilers, this boiler attains highpressures, as well as highsteam capabilities, can be achieved. A firetube boiler is a type of boiler in which hot gases from the fire pass through one or more tubes within the boiler. If the fitting is exposed to temperatures at or above this melting point, the eutectic alloy plug will melt and the pressure inside the fitting will be released to atmosphere. Chanter biomed healthcare products, boiler spares and stairlift spares. Fusible plug boiler and pressure vessel engineering engtips. The highpressure steam pushes the remaining water through this hole on the grate and the fire is extinguished. It protects the boiler against damage due to overheating for low water level. They are used as safety equipment with the aim to take a fire and automatically activate all the. First of all you should understand that there are many types and nomenclature of boilers. And for obvious reasons, if the steam box becomes soft, it would not be able to maintain the boiler pressure, resulting in an explosion.
In steam engines the fusible plug is screwed into the crown sheet the top plate of the firebox, typically extending about an inch 25mm into the water space above. The hot steam melts and blows the tin out, allowing steam to escape from the boiler warning the operator. Third plug is made from copper is locked with the second plug by pouring metal in to the grooves provided on the both plugs. Top 50 boiler information booster question answers. The earliest form of firetube boiler was richard trevithicks highpressure cornish boiler.
Fusible plugs are installed between the fireside of either the plate, flue or tube of the boiler and below the water level. It is an improved type of simple vertical boiler in order to minimize heating surface. It describes a method of stopping a boiler tube which is leaking in a manner which expansion will not cure. Green berets ultralight bug out bag with gear recommendations duration. While in water tube boilers, water passes through tubes.
Fusible fittings warning fusible fittings contain an eutectic alloy plug. In water tube boilers there is no fusible plug and there is a safety valve. This is an internally fired boiler because the furnace uses to present inside the boiler. Locomotive boiler is a horizontal fire tube type mobile boiler. This manual has several features which make it easier to use online. Fusible plugs may be water side, or, fire side plugs. An investigation of fusible tin boiler plugs nist page.
Its working depends upon the water level in the boiler shell it is a threaded metallic cylindrical object, with a tapered hole in it which goes through its entire length. This boiler delivers to site as a whole package factory assembled. The boiler vent is located at the highest part of the steam side of the boiler. The package boiler only requires electricity, water, steam and fuel connections and it is ready to produce steam. Swagelok fusible plug and a swagelok mud dauber fitting. Fusible plugs general boiler spares products chanter. Fusible plug a hollowed threaded plug having the hollowed portion filled with a low melting point material used, for example, in the crown of a boiler firebox. If the water level falls below them the metal in the plug melts and steam is dumped into the firebox to prevent serious overheating of the plates. The main function of a boiler is to heat water for steam generation. Fusible plug is a fitting used in steam boilers to enhance the safety during operation. Fusible plugs are sometimes used on fire tube boilers to provide added protection against low water. With over 40 years of experience in steam preservation, we can aid you in finding the right product for your needs from our knowledgeable sales team. Water tube boiler working principle, types of water tube. The initial use of the fusible plug was as a safety precaution against low water levels.
Globe technologies is the industryleading manufacturer of fusible valves, specifically designed to handle pneumatic applications. It is fitted on the fire box crown plate or over the combustion chamber at its appropriate place. May 03, 2018 green berets ultralight bug out bag with gear recommendations duration. The universal type of steam boilers is the smoke tube or fire tube boiler where the heat and gases of combustion from furnace pass through tubes that are enclosed by water. This is because of condensed tangential pressure on tubes which is known as hoop stress. A steam boiler is a closed vessel, generally made of steel, in which water is heated by some source of heat produced by combustion of fuel and ultimately to generate steam. The boiler is of a wet back design with a fully submerged combustion chamber and firing tube. What is the melting teparature of the boiler fusible plug. How fusible plugs work industrial engineering youtube. Fusible plug boiler and pressure vessel engineering. The fire itself was on an iron grating placed across this flue, with a shallow ashpan beneath to collect the noncombustible residue.
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