When cooling down a steam boiler that has been taken out of service, a vent valve on the steam drum should be opened to

When cooling down a steam boiler that has been taken out of service, a vent valve on the steam drum should be opened to

a) prevent a vacuum from forming in the boiler
b) release the air from the boiler
c) purge the shell of impure gases
d) let the operator know when the pressure has reached zero
e) prevent pressure build-up in the boiler

Answer: A

On boiler cool-down the vent should be opened

On boiler cool-down the vent should be opened

a) as soon as the post-purge is completed
b) when all temperatures are at ambient value
c) any time after the NRV is closed
d) just before the unit goes into a vacuum
e) at no time

Answer: D

Before removing a boiler from service for maintenance purposes it is beneficial to

Before removing a boiler from service for maintenance purposes it is beneficial to

a) inform the Chief Inspector
b) do as little as possible with the waterside of the unit
c) use sootblowers and clean the fireside well
d) force cool the unit with post-purge air
e) drain the unit before the water cools to ambient temperature

Answer: C

Two boilers are feeding into the same steam header and each pressure gage shows a pressure of 350 kPa. The steam pressure gage on the header will indicate

Two boilers are feeding into the same steam header and each pressure gage shows a pressure of 350 kPa. The steam pressure gage on the header will indicate

a) slightly more than 350 kPa
b) 700 kPa
c) slightly more than 700 kPa
d) slightly less than 350 kPa
e) slightly less than 700 kPa

Answer: D