What are the Boiler Mountings?

Boiler Mountings:  There are different fittings and devices which are mounted or installed on the boiler for its safe & proper  operation. Normally boiler mountings are mounted over the boiler shell.

Boiler mounting are given below:

• Water level indicator
• Pressure gauge
• Safety valve
• Steam Stop valve
• Blow off cock
• Feed check valve
• Fusible plug

Functions/Applications of different boiler mountings:

>> Water level indicator:

It is an important fittings, which indicates the water level inside the boiler to an observer. It is a safety device, upon which the correct working of the boiler depends. This fittings may be seen in front of the boiler. Water level indicator are generally two in number.

>> Pressure Gauge:

A pressure gauge is used to measure the pressure of the steam inside the steam boiler. It is normally mounted in front top of the shell or drum. It is usually constructed to indicated upto double the maximum working pressure. The Pressure gauges generally used are of Bourden type.

>> Safety Valve:

The function of a safety valve is to release the excess steam when the pressure of steam inside the boiler exceeds the rated pressure. As soon as the pressure of steam inside the boiler exceeds the rated pressure the safety valve automatically opens and excess steam rushes out into the atmosphere till the pressure drops down to the normal value. A safety valve is generally mounted on the top of the shell.

A steam boiler is usually provided with the two safety valves & normally Spring loaded safety valve are employed in the boiler.

>> Steam stop valve:

It is the largest valve on the steam boiler. It is usually fitted to the highest parts of the shell by means of a flange. The main functions of a steam stop valve are:

i) To control the flow of steam from the boiler to the main pipe.

ii) To shut off the steam completely when required.

 >> Blow off cock:

The principle functions of a blow off cock are:

i) To empty the boiler whenever required.

ii) To discharge the mud, scale or sediments which are accumulated at the bottom of the boiler.

>> Feed check valve:

It is a non return valve, fitted to a screwed spindle to regulated the lift. Its function is to regulate the supply of water, which is pumped into the boiler, by the feed pump. This valve must have its spindle lifted before the pump is started. It is mounted to the shell slightly below the normal water level of the boiler.

>> Fusible plug:

It is fitted to the crown plate of the furnace or the fire box. Its function 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 thus avoids the explosion which may take place due to the overheating of the furnace plate.