BOILER MOUNTINGS &
• Boiler mountings are primarily intended
for the safety of the boiler and for
of steam generation process.
Boiler Accessories :
• Boiler accessories are installed to
increase the efficiency of the boiler plants to help
working of boiler unit.
Dead weight safety valve.
Spring loaded safety valve
Dead Weight Safety Valve:
Dead Weight Safety Valve:
Weights are placed sufficiently in the weight
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.
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
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
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
The pointer is mounted on the pinion. Hence the
pointer moves on the graduated dial in clockwise, to indicate the steam
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
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
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