Boiler Mountings and Accessories

BOILER MOUNTINGS & ACCESSORIES:

Boiler Mountings:

• Boiler mountings are primarily intended for the safety of the boiler and for complete control of steam generation process.

Boiler Accessories :

• Boiler accessories are installed to increase the efficiency of the boiler plants to help in proper working of boiler unit.

Boiler Mountings:

•           Dead weight safety valve.

•           Spring loaded safety valve

•           Fusible plug

•           Pressure gauge

Dead Weight Safety Valve:

Dead Weight Safety Valve:

•         Weights are placed sufficiently in the weight carrier.

•         The total load on the valve includes the weight of the carrier, the weight of the cover, the weight of the discs and the weight of the valve itself.

•         When the steam pressure exceeds the normal limit, the valve along with the weight carrier is lifted off its seat.

•           Thus the steam escapes through the discharge pipe.

Spring Loaded Safety Valve:

•         The steam pressure a cts below the valves.

•   When the steam pres sure is normal the valves are held in their seats tightly by the spring force.

•         When the steam presssure in the boiler exceeds the working pressu re, both valves are lifted off their seats.

•           Thus the steam from the boiler escapes the boiler and steam pressure is reduced.

•           The blow off pressure is adjusted by loosening or screwing the nut.

Fusible Plug:

•         Under normal workin g conditions, the fusible plug is completely covered with water.

•         Hence the temperature of the plug is not increased appreciably du ring combustion process.

•         When the water level falls below the safe limit the fusible plug is unc overed from water and exposed to steam.

•         The furnace heat over heats the plug and it melts the fusible me tal and

copper plug falls down.

• Due to this water st eam mixture rushes into the furnace and the fire is extinguished.

Bourdan Tube Pressure Gauge

•   The  steam  pressure  is  applied  to  the

•           The elliptical cross section of the tube to straighten out slightly.

•           The closed end of the Bourdon tube moves.

•           This movement actuates the toothed sector and pinion rotates.

•         The pointer is mounted on the pinion. Hence the pointer moves on the graduated dial in clockwise, to indicate the steam pressure.

Water Level Indicator

•         To know the water level in the boiler the handles of the steam cock and water cock are kept in vertical positions.

•         Water rushes through the bottom casting and steam rushes through the upper casting to the gauge glass tube.

•         The level of water corresponds to the water level in the boiler.

DIFFERENCES BETWEEN BOILER MOUNTINGS AND ACCESSORIES:

Boiler Mountings

Mountings are fitted for the safety of the boiler.

They form integral parts of the boiler

They are usually mounted on the boiler shell

A boiler should not be operated without mountings

Boiler Accessories

Accessories are fitted to increase the efficiency

They are not integral part of the boiler

They are usually installed outside the boiler shell

A boiler can be operated without accessories