Boilers Flashcards
no visible level in visible gauge glass
turn off flame to prevent further damage.
blow down the guage glass to confirm the low level.
if still low shut down boiler, let it cool down before further investigation
safety valve lifting
there is too much pressure in the boiler, check the pressure guage, check the guage glass, operate the easing gear on both safety valves to make sure they are fully open
excessive smoking during firing
incorrect fuel to air ratio. so first check the air damper to make sure that the damper positioning is correct for the amount of fuel. check the fuel pressure is correct for the amount of air, and finally check that the fuel temperature is correct for atomisation.
excessively high chloride content of boiler water
identify the source, isolate the source. possibly condenser. do blow down tests, refill with clean uncontaminated water. retest to check if the source of contamination was correct
four test that can be done on the boiler water
chloride
P alkalinity
Total alkalinity
Phosphate
high level
boiler will cut out more often
will cause priming where water is carried over into the steam line, also water hammering.
low level
boiler has to run for longer, boiler efficiency drops as it has to run for longer to produce steam
low low level
causes over heating, it will also lead to high thermal stress
blow down of the guage glass
close water and steam open drain open steam close steam open water close water and drain open water allow to fill open steam
four reasons for the boiler feed pump failing to maintain boiler water level
blow down valve open
hot well low level
faulty feed valve
water locking, water has turned into steam and it can not be pumped
how do you start up a boiler
fill with water
check safeties e.g. flame failure, high level low level
purge boiler
start up slowly to prevent thermal shock
at 1 bar close vent to keep efficency in the boiler
steam should be coming out of vent before closing
build up the water pressure
when shutting down open vent again to prevent vaccum
8 boiler mountings
feed water valve main steam stop valve pressure guage blow down valve scum valve 2 safety valves 2 guage glasses sample cocks
2 consequences of not treating boiler water
scaling
corrosion
four circumstances where fuel supply to the burners would be cut off
low level alarm
high pressure alarm
flame Eye failure
failure to purge loss of control of dampener
water level indicators mounted on the boiler?
guage glasses
