Lesson 5 - Steam Technology SAQ
This lesson allows you to test yourself on the material covered in the Steam Technology lesson and determine the level to which you have met the learning outcomes.
Suggested Response - Q4
** What controls are required to ensure the safe operation of a boiler?
Response:
Boiler pressure control should never allow the boiler pressure to go beyond the rating for the boiler. The pressure is usually controlled by controlling the fuel supply. A pressure switch can also be used to shut off the fuel supply if the maximum value for steam pressure is reached. Lastly, a mechanical safety feature in the form of a pressure relief valve should be fitted to the boiler.
The boiler water level should also be carefully controlled to ensure that the tubes are covered and protected from a low level situation. This will also ensure that the level is never too high, which can result in water carryover to the steam network. The water pump is controlled by a level transmitter. There are usually two independent level switches, which will shut the burner off if a low level is detected. A high level switch can also shut off the water pump if a high level is detected.
Another potentially dangerous situation occurs if the flame goes out in the boiler. If the fuel continues to be pumped into the boiler, this could result in an explosion when it is ignited. Thus a flame detection system shuts a valve on the fuel supply to the boiler if a flame is not detected.