GFSE-Std-0499
3 3
3.6.4 First Low Water Level
(a) Ensure the following:
The burner is firing.
The water level is correct in the boiler.
The water pump is not running.
(b) Switch the pump OFF at the pump overide switch.
(c) OPEN the main blowdown valve.
(d) When the water level nears the bottom of the water level gauge sight glass, the low water alarm
should sound, the LOW WATER ALARM lamp should illuminate and the burner should stop firing.
When this happens, CLOSE the blowdown valve IMMEDIATELY.
(e) Switch the pump ON at the main pump overide switch. The pump should run and refill the boiler.
When the water level in the boiler rises above the first low water level, the LOW WATER
LEVEL lamp should extinguish, the audible alarm should silence and the burner start sequence
should commence automatically. The pump should run until the boiler water level is correct and then
stop.
23
3.6.5 Overriding Low Water Check
(a) Ensure the following:
The burner is firing.
The water level is correct in the boiler.
The water pump is not running.
(b) Switch the pump OFF at the pump override switch.
(c) OPEN the main blowdown valve.
(d) When the water level nears the bottom of the water level gauge sight glass, the LOW WATER
ALARM lamp should illuminate, the low water audible alarm should sound and the burner should
stop firing.
(e) Continue to blow down. As the water level falls nearer the bottom of the water level gauge sight
glass, the LOW WATER RESET switch should illuminate and the second audible low water alarm
should sound.
(f) CLOSE the main blowdown valve and switch the pump ON at the pump override switch. The water
pump should now start to run and refill the boiler. Once filled to the correct level the water pump
should stop. The low water alarm should continue to sound, the LOW WATER RESET switch and
LOW WATER ALARM lamp should remain illuminated and the burner should NOT start.
(g) When the water level in the boiler is correct, the burner can be restarted by depressing the LOW
WATER RESET switch for a maximum of 2 seconds.
1. The First and Overriding low water checks can be carried out in one operation to reduce the
blowdown time and possible interruption to the steam supply.
2. Where the water level tests are to be carried out at full pressure, evaporate the water down to
1st. low level as in 3.8, blowdown the boiler from 1st. to 2nd. low water.
The purpose of adopting this procedure is to prevent steam and water being expelled from the
blowdown vessel vent because of prolonged blowdown.
To Next Page
Loading...
