This document discusses the mountings and accessories of boilers. It defines mountings as items used for safety and accessories as items used to increase efficiency. It then lists and describes the common mountings, which include water level indicators, pressure gauges, safety valves, fusible plugs, blow-off cocks, steam stop valves, and feed check valves. Accessories are described as economizers, preheaters, superheaters, steam separators, injectors, and feed pumps. The purpose and function of each accessory is explained.

1. STUDY
OF
BOILER MOUNTINGS
&
ACCESSORIES
by
Prof. S. R. Khandagale
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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2. Mountings:
The items which are used for safety of boiler
are called mountings
Accessories:
The items which are used for increasing the
boiler efficiency are called accessories
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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3. MOUNTINGS
1. Water Level indicator
2.Pressure Gauge
3. Safety valves
A. Dead weight safety valve
B. Spring loaded safety valve
C. Lever controlled safety valve
D. High steam & low water safety valve
4. Fusible plug
5. Blow-off cock
6. Steam stop valve
7.Feed check Valve
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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4. Water Level indicator
For indicating water
level inside boiler
Usually 2 Nos.
Steel balls are provided
to prevent loss of
steam in case of glass
breakage
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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5. Pressure Gauge
To indicate
level of steam
pressure
inside the
boiler
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
5

6. Safety valves
• Safety valve releases steam outside of boiler in
case of excess pressure inside
A. Dead weight safety valve
B. Spring loaded safety valve
C. Lever controlled safety valve
D. High steam & low water safety valve
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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7. Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
7

8. High steam & low water safety valve
Actuates in 2 situations
1. Water level lowers 2. steam pressure increases
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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9. FUSIBLE PLUG
Function is to extinguish
(switch off )fire when
water level in boiler falls
below certain limit
Fusible material is having
low MP
e.g. brass, gunmetal
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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10. BLOW OFF COCK
• To drain out water
from the boiler for
internal cleaning
inspection or other
purposes
• Fitted at lowest
part of boiler
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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11. STEAM STOP VALVE
Regulates the flow of a
steam
Function : to shut off or
regulate the flow of steam
from the boiler to the
steam pipe or steam
from the steam pipe to
the engine
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
11

12. FEED CHECK VALVE
• To allow the feed
water to pass in to
the boiler
• To prevent the back
flow of water from
the boiler in the
event of the failure
of the feed pump
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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13. 1. Economizer
2. Preheater
3. Superheater
4.Steam separator
5.Injector
6. Feed pump
ACCESSORIES
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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14. Economizer ,Preheater & Superheater
Use to recover some heat being carrying by exhaust
flue gases.
Heat recovered is utilized in --> Economizer
raising the temperature
of the feed water
Heat recovered is utilized in --> air preheater
raising the temperature
of the fresh air
Heat recovered is utilized in --> super heater
raising the temperature
of the (saturated )steam
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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15. Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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16. SUPERHEATER
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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17. AIR PREHEATER
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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18. GREEN’S ECONOMISER
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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19. STEAM SEPERATOR
• Separates
moisture
contain in
steam and
makes it dry
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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20. STEAM INJECTOR
Function of injector is to
feed water into the boiler
It is commonly employed for
vertical and locomotive
boilers
Not suitable for large
capacity high pressure
boilers
Also used where the space
is not available for the
installation of feed pump
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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21. FEED PUMP
• Used to deliver feed water to the boiler.
• It is desirable that the quantity of water supplied
should be at least equal to that evaporated and
supplied to the engine
• Two types of which are commonly used as feed pumps
are
• (1) reciprocating pump
• (2) rotary pump
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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22. RECIPROCATING TYPE BOILER FEED
PUMP
Prof. S.R.
Khandagale,JJMCOE,Jaysingpur,Mahrashtra
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