What should be the location of fusible plug in fire tube and water tube boiler?
Fire tube boiler fusible plugs are installed 1 to 2 inches above the highest row of tubes. 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).
Can we operate a boiler without fusible plug?
These are not essential parts of the boiler, without which the boiler can operate at lower efficiency. Examples: Superheater, Feed Pump, Injector, Economizer, Steam Separator, Air preheater, etc.
At what temperature does a fusible plug melt?
Fire-activated fusible plugs are filled with pure tin and feature a melting point between 445°F and 450°F.
Where is the fusible plug located in boilers?
A fusible plug operates as a safety valve when dangerous temperatures, rather than dangerous pressures, are reached in a closed vessel. In steam boilers 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.
Which one is accessory of boiler?
The essential boiler accessories are: Air pre-heater. Superheater. Feed pump. Steam Separator.
What kinds of metal in the fusible plug melts when overheating occurs?
A proper material for fusible plugs is commercial tin, the melting point of which is about 450 degrees F, or an alloy of two parts of lead and one of tin, having a melting point of 440 degrees F. In some places the law requires the use of Banca tin in fusible plugs. This metal has a melting point of 450 degrees F.”
On what basis are fire and water tube boilers are classified?
On what basis are fire and water tube boilers are classified? Explanation: Based on the contents of the tubular heating surface, boilers are primarily classified as fire tube boiler and water tube boiler.
Which of the following is not a boiler mounting?
9. Which of the following is NOT a boiler mounting? Explanation: Steam stop valve, Man hole and pressure gauge are boiler mountings. Economizer is a boiler accessory.
What is a fusible plug made of?
bronze
A fusible plug is a threaded metal cylinder, often made from bronze, brass or gunmetal, which has a tapered hole drilled completely through its length. This hole is sealed with a metal of low melting point that flows away if a pre-determined, high temperature is reached.
What is boiler accessories .define any three?
The various boiler mountings and accessories that are used in steam boilers are water level indicator, pressure gauge, safety valves, stop valve; blow off Valve, feed check valve, fusible plug, air pre-heater, super heater, economiser and feed pump.
What is the capacity of a fire tube boiler?
Fire tube boilers, typically have a lower initial cost, are more fuel efficient and easier to operate. Their capacities are up to 25tons/hr and 17.5 kg/ cm2. These are the earliest form of high pressure fire tube boiler.
How does a high pressure fire tube boiler work?
These are the earliest form of high pressure fire tube boiler. These consist of long horizontal cylinder with single large flue containing fire. Fuel is added in the grate area where it burn to produce hot gases. The hot gases transfer the heat to the water. Water takes heat and after some time it starts boiling to produce steam.
What are shell and tube boilers?
Shell and tube boilers are also referred to as fire tube or smoke tube boilers. Fire tube boilers; contain long steel tubes through which the hot gasses from a furnace pass and around which the water to be converted to steam circulates.
What is a high capacity boiler?
Modern high capacity boilers are of water tube type. The boiler circulation system is constructed of tubes, headers, and drums joined in arrangement that provide water flow to generate steam. Water tubes have high pressures and capacity than shell tube boilers.