4B Power Engineering - Final - Nait
Knowledge Checks fully solved
C - correct answer ✔✔A hot water boiler operating control (Aquastat) may be a pressure switch:
*A* that is normally open
*B* that responds to the expansion and contraction of boiler water
*C* operated by a filled system thermometer
*D* that is sensitive to steam pressure
B - correct answer ✔✔A light fuel oil flame should
*A* impinge on the refractory, to stabilize ignition.
*B* be bright yellow, with orange at the tips of the flame.
*C* be predominantly blue, with orange at the tips of the flame.
*D* be bright yellow, with smoke at the tips of the flame.
C - correct answer ✔✔The purpose of the pipe siphon installed between the boiler and the
pressure gauge is to prevent:
*A* Air from entering the gauge
*B* Water from entering the gauge
*C* Hot steam from entering the gauge
*D* Air from entering the boiler
,C - correct answer ✔✔Boilers should be warmed up
*A* with maximum combustion air, to prevent smoking
*B* rapidly, so the metal heats up faster
*C* slowly, to minimize differential expansion and thermal shock
*D* using only the pilot burner.
C - correct answer ✔✔The discharge pipe from a boiler safety valve is supported independently
of the safety valve:
*A* Because the steam drum cannot support the extra mass of the discharge pipe
*B* So the discharge pipe can drain more easily
*C* So the discharge pipe can expand without putting force on the safety valve
*D* To prevent leakage at the pipe joint
C - correct answer ✔✔A modulating control steam heating boiler:
*A* Is always fully automatic
*B* Will have a narrow operating pressure range
*C* Maintains a steadier boiler pressure than multi-position control
*D* Will have a constant combustion air flow rate
C - correct answer ✔✔Which of the following is a desiccant used for dry layup?
*A* Silicone Gel
*B* Lime soda
,*C* Quick lime
*D* Soda ash
C - correct answer ✔✔The prime importance of boiler fittings is:
*A* Economics
*B* To satisfy regulations
*C* Safety & efficiency
*D* Convenience
D - correct answer ✔✔If a new boiler is not boiled out correctly, the result may be:
*A* Refractory damage
*B* Excessive waterside corrosion
*C* Excessively high water circulation rates
*D* Foaming
D - correct answer ✔✔Because natural gas is colourless and odourless, ___________ is added
to the gas so that it is easier to detect a leak.
*A* fluorescent dye
*B* propane
*C* an irritant
*D* mercaptan
C - correct answer ✔✔One purpose of the small valve on top of the shell of most boilers, which
is not required by code, is to:
, *A* allow water into the boiler when the boiler is being drained or cooled preventing the
formation of a vacuum.
*B* allow water to escape before the steam stop valve is opened during the warm-up period.
*C* allow air to escape from the boiler when the boiler is being filled with water.
*D* allow air into the boiler when the boiler is being filled with water.
C - correct answer ✔✔Mechanical chart recorders
*A* require regular replacement of paper and ink.
*B* need their charts replaced each month.
*C* require constant winding of their clock mechanisms.
*D* are used so regular readings do not need to be taken.
A - correct answer ✔✔Tubular gauge glasses:
*A* Are suitable for pressures up to about 3000 kPa
*B* Are made of glass, in order to resistant boiler alkalinity
*C* Indicate the level more accurately than other forms of water level indication
*D* Can only be installed on low-pressure boilers
C - correct answer ✔✔What is the recommended test frequency for flame safeguard devices?
*A* every shift
*B* daily
*C* weekly
Knowledge Checks fully solved
C - correct answer ✔✔A hot water boiler operating control (Aquastat) may be a pressure switch:
*A* that is normally open
*B* that responds to the expansion and contraction of boiler water
*C* operated by a filled system thermometer
*D* that is sensitive to steam pressure
B - correct answer ✔✔A light fuel oil flame should
*A* impinge on the refractory, to stabilize ignition.
*B* be bright yellow, with orange at the tips of the flame.
*C* be predominantly blue, with orange at the tips of the flame.
*D* be bright yellow, with smoke at the tips of the flame.
C - correct answer ✔✔The purpose of the pipe siphon installed between the boiler and the
pressure gauge is to prevent:
*A* Air from entering the gauge
*B* Water from entering the gauge
*C* Hot steam from entering the gauge
*D* Air from entering the boiler
,C - correct answer ✔✔Boilers should be warmed up
*A* with maximum combustion air, to prevent smoking
*B* rapidly, so the metal heats up faster
*C* slowly, to minimize differential expansion and thermal shock
*D* using only the pilot burner.
C - correct answer ✔✔The discharge pipe from a boiler safety valve is supported independently
of the safety valve:
*A* Because the steam drum cannot support the extra mass of the discharge pipe
*B* So the discharge pipe can drain more easily
*C* So the discharge pipe can expand without putting force on the safety valve
*D* To prevent leakage at the pipe joint
C - correct answer ✔✔A modulating control steam heating boiler:
*A* Is always fully automatic
*B* Will have a narrow operating pressure range
*C* Maintains a steadier boiler pressure than multi-position control
*D* Will have a constant combustion air flow rate
C - correct answer ✔✔Which of the following is a desiccant used for dry layup?
*A* Silicone Gel
*B* Lime soda
,*C* Quick lime
*D* Soda ash
C - correct answer ✔✔The prime importance of boiler fittings is:
*A* Economics
*B* To satisfy regulations
*C* Safety & efficiency
*D* Convenience
D - correct answer ✔✔If a new boiler is not boiled out correctly, the result may be:
*A* Refractory damage
*B* Excessive waterside corrosion
*C* Excessively high water circulation rates
*D* Foaming
D - correct answer ✔✔Because natural gas is colourless and odourless, ___________ is added
to the gas so that it is easier to detect a leak.
*A* fluorescent dye
*B* propane
*C* an irritant
*D* mercaptan
C - correct answer ✔✔One purpose of the small valve on top of the shell of most boilers, which
is not required by code, is to:
, *A* allow water into the boiler when the boiler is being drained or cooled preventing the
formation of a vacuum.
*B* allow water to escape before the steam stop valve is opened during the warm-up period.
*C* allow air to escape from the boiler when the boiler is being filled with water.
*D* allow air into the boiler when the boiler is being filled with water.
C - correct answer ✔✔Mechanical chart recorders
*A* require regular replacement of paper and ink.
*B* need their charts replaced each month.
*C* require constant winding of their clock mechanisms.
*D* are used so regular readings do not need to be taken.
A - correct answer ✔✔Tubular gauge glasses:
*A* Are suitable for pressures up to about 3000 kPa
*B* Are made of glass, in order to resistant boiler alkalinity
*C* Indicate the level more accurately than other forms of water level indication
*D* Can only be installed on low-pressure boilers
C - correct answer ✔✔What is the recommended test frequency for flame safeguard devices?
*A* every shift
*B* daily
*C* weekly
