TM 5-810-15
(3) Thermometers. Thermometers are used to
(5) Temperature switches. Temperature
provide local indication of process temperatures.
switches are used to monitor temperatures for
Thermometers are normally the bimetallic type for
remote indications, interlocking functions, and
most applications. Scale ranges will be selected
alarm conditions. Temperature switches may have
such that the normal operating temperature is at
snap acting switch contacts or mercury switch
approximately mid-scale. Thermometers will be
contacts and may be bulb and capillary type or
provided with thermowells so the thermometer
direct insertion type. Thermowells of suitable rating
sensing element is not inserted directly into the
will be supplied so the sensing element is not
process. Thermowells will be designed to withstand
inserted directly into the process.
(6) Pressure controllers. Pressure controllers
the pressure, temperature, and fluid velocities of
the process in which they are inserted. Thermowells
will be pneumatic with bourdon tube or bellows
installed in piping will be long enough to extend to
sensing element. The sensing element will be
approximately the pipe centerline. Thermowells will
suitable for the pressure and temperature of the
have extensions to clear insulation and lagging.
process fluid to be controlled and will be an integral
(4) Thermocouples. Thermocouples are used
part of the controller assembly. The sensing
to provide remote indication and control of process
element will have adequate sensitivity and be able
temperatures. Type J or Type K thermocouples are
to withstand the maximum pressure under all
normally suitable for steam plant applications as
conditions. Pressure controllers will have adjustable
discussed in paragraph 9-6b(5). Thermocouples
proportional and reset control action, control point
will be provided with thermowells or protection
adjustment, calibrated pressure setting dial, air
tubes of suitable rating. Thermowell or protection
supply filter regulator, and gauges which indicate
tube length will be sufficient to provide the neces-
air supply and controller output pressures. Pressure
sary insertion length plus the desired nipple length.
controllers will be mounted on the operator of the
Thermocouple assemblies will also include
valve to be regulated.
insulators and terminal head with cover.
Table 9-4. Operator Interface Instrumentation Requirements.
Pulverized Coal Fired
Gas/Oil Fired Boilers
Stoker Fired Boilers
Boiler
Operator Stations:
1. Boiler Master
R
1.
Boiler Master
R
1.
Boiler Master
R
2. Air Flow
X
2.
Air Flow
R
2.
Air Flow
R
3. Fuel flow
X
3.
Fuel Flow
R
3.
Pulverizer Master
X
4. Drum Level
R
4.
Drum Level
R
4.
Pulverizers
R
5. Oxygen Trim
X
5.
Oxygen Trim
X
5.
Primary Air
R
6. Furnace Pressure
6.
Furnace Pressure
R
6.
Drum Level
R
7. Steam Temperature
7.
Steam Temperature
R
7.
Oxygen Trim
R
(SH only)
R
(SH only)
8.
Furnace Pressure
R
8. Deaerator
8. Deaerator
9.
Steam Temperature
Pressure
X
Pressure
X
(SH only)
R
9. Deaerator Level
X
9. Deaerator Level
R
10.
Deaerator Pressure
X
10. Feedwater Heater
X
10. Feedwater Heater
X
11.
Deaerator Level
R
11. Steam Coil
12.
Feedwater Heater
X
Preheater
R
13.
Steam Coil
Preheater
R
Recorder Requirements:
1. Steam Pressure
R
1.
Steam Pressure
R
1.
Steam Pressure
R
2. Steam Flow
X
2.
Steam Flow
R
2.
Steam Flow
R
3. Fuel Flow
X.
3.
Steam Temperature
3.
Steam Temperature
4. Drum Level
R
(SH only)
R
(SH only)
R
5. Percent Oxygen
R
4. Feedwater Flow
R
4. Feedwater Flow
R
6. Steam Temperature
5. Feedwater
X
5. Feedwater
X
(SH only)
R
Temperature
Temperature
7. Deaerator
X
6. Deserator
K
6. Deaerator
X
Pressure
Pressure
Pressure
8. Deaerator Level
K
7. Deaerator Level
X
7. Deaerator Level
K
9. Feedwater Temp
X
8. Drum Level
R
8. Drum Level
R
10. Exit Gas Temp
R
9. Air Flow
R
9. Total Air Flow
R
11. Feedwater Flow
R
10. Percent Oxygen
R
10. Percent Oxygen
R
12. Air Flow
X
11. Fuel Flow
K
11. Total Fuel Flow
K
9-25
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