Use of mountings and accessories of Boiler
Boiler mountings are used to run a boiler in a safe way ex: safety valve, Water level indicators etc. Boiler mountings are primarily intended for the safety of the boiler and for complete control of steam generation process.
Boiler accessories are used to improve the efficiency of a boiler ex: economizer, air preheater etc. Boiler accessories are installed to increase the efficiency of the boiler plants to help in proper working of boiler unit.
- Boiler mountings are components used for ensuring the safety of boiler operation.
- These are generally mounted on the surface of the boiler.
- Control fluid parameters at the inside of the boiler shell.
- The mountings are the essential part of a boiler, without which boiler operation is impossible.
Examples: Pressure gauges, Water level indicator, Safety valves, Stop valve, Fusible plug, Blow off cock, etc.
- Accessories are the auxiliary items required for proper operation of boiler and improve the efficiency of it.
- These are integral parts of the boiler, but not mounted on it.
- Control fluid parameters at outside of the boiler.
- These are not essential parts of the boiler, without which boiler can operate though at lower efficiency.
Examples: Super heater, Feed pump, Injector, Economizer, Steam separator, Air preheater, etc.
Difference between Boiler Mountings and Accessories
The different boiler mountings and accessories that are installed on the steam boiler are as follows
- Water level indicator ( Water level gauge)
- Pressure gauge
- Safety valves
- Stop valve
- Blow off cock (Blow off valve)
- Feed check valve
- Air pre-heater
- Super heater
- Feed pump
The function of various boiler mountings and accessories are:
1. Water Level Indicator
- It is fitted in front of the boiler and generally present two in number.
- It is used to indicate the water level inside the boiler. It shows the instantaneous level of water that is present inside the steam boiler which is necessary for its proper working.
2. Pressure gauge
- It is also present in front of the boiler.
- It is used to measure the pressure of the steam inside the boiler.
The pressure gauges generally used are of Bourden type
3. Safety Valves
- Safety valves are attached to the steam boiler chest.
- It is used to prevent explosion due to excessive internal pressure. When the internal pressure inside the boiler exceeds its working pressures than the safety valves blow off the steam and maintains the internal pressure.
Generally two safety valves are present on a boiler.
4. Stop Valve (steam stop valve)
It is usually fitted on the highest part of the boiler with the help of a flange.
The main function of the stop valve is
- To control the flow of steam from the boiler to the main steam pipe.
- To completely shut off the steam supply when required.
5. Blow Off Cock
- It is fitted at the bottom of the boiler drum.
- The functions of blow off cock is
- To empty the boiler whenever required.
- To discharge the scale, mud and sediments which gets collected at the bottom of the boiler.
6. Feed Check Valve
- It is non-return valve and fitted to a screwed spindle to regulate the lift.
- It is fitted to the shell slightly below the normal water level of the boiler. A boiler must have its spindle lifted before the pump is started.
- It regulates the supply of water which is pumped into the boiler by feed pump.
7. Fusible Plug
- It is fitted to the crown plate of the furnace or firebox.
- Its function is to extinguish fire in the furnace when the water level in the boiler falls to an unsafe limit. This avoids the explosion that may takes place because of the overheating of the furnace plate.
the boiler accessories are the integral parts of the boiler. They are used in the boiler to improve its efficiency.
1. Air preheater
- It is used to recover heat from the exhaust gases.
- It is installed between the economiser and the chimney.
2. Super heater
- It is placed in the path of hot flue gases from the furnace.
- A super heater is an important accessory used in the boiler.
- Its main function is to increase the temperature of saturated steam without raising its pressure.
- It is used to heat the feed water by the utilization of heat from the hot fuel gases before it leaves the chimney.
- A economiser improves the economy of the steam boilers.
4. Feed pump
- It is used to deliver water to the boiler.
- This is the brief introduction of important boiler mountings and accessories. If you find anything missing or incorrect than let me know about it through your comments.