POWER ENGINEERING 2A3 COMPLETE EXAM LATEST 2026
UPDATED QUESTIONS AND VERIFIED 100% SOLUTIONS
(2026/2027) GRADE: A+|STATUS: GUARANTEED PASS
What is a heavy metal? - Answers -Any metallic element that has a relatively high density and is
toxic at low concentrations.
Mercury, cadmium, arsenic, chromium, thallium, and lead.
How is lead removed from water? - Answers -Because lead remains suspended rather than
dissolved, it is easily removed by filtration.
How is phosphate removed from water? - Answers -Phosphate can be precipitated at a pH over
10.0 with alum, sodium aluminate, or ferric chloride.
How is zinc removed from water? - Answers -It is removed by lime softening or by cation
exchange.
How is chromium removed from water? - Answers -It can be reduced by filtration and anion
exchange.
1|Page
,How is nickel removed from water? - Answers -It can be precipitated or removed by cation
exchange.
How are suspended solids removed? - Answers -They are removed by coagulation and
sedimentation, followed by filtration. The water must be free of suspended solids before it is
further purified in the demineralization section of the plant.
At what operating pressure must the sodium ions be removed? - Answers -Above 4000 kPa
Name some common oxygen scavengers - Answers -- Sodium sulphite
- Hydrazine
- Hydroquinone
- Ethyl ketoxime
At saturation temperature, all gases are - Answers -in free form.
What are the metal concentrations in a cooling tower, in comparison to make-up water? -
Answers -Due to the partial evaporation of the water in the cooling tower, the water may have
10 - 15 cycles of concentration (or 10 -15 time more).
What is the time limit for stocking reagents? - Answers -The maximum stock is often limited to a
six months supply
2|Page
,What is an indicator? - Answers -It is a solution that exhibits a change in colour when a very
small quantity is dissolved in a sample of water whose acidity or alkalinity is within a specific
range.
They are organic compounds with complex formulae and are themselves weak acids or alkalis.
Phenolphthalein, methyl orange solution, starch solution, pH indicator solution.
What is a reagent? - Answers -It is a substance that is used to produce specific reactions with
constituents of water that require measurement.
What does NTU stand for? - Answers -Nephelometric Turbidity Unit
What chemical is common for inhibiting embrittlement in boilers? - Answers -Sodium nitrate is
common for boilers up to 6700 kPa.
At higher pressures, coordinated phosphate/pH control is the usual internal treatment.
What is a mho? - Answers -A mho is a unit of electrical conductivity which is the reciprocal of an
ohm, the unit of electrical resistivity.
1 mho = 1/ohm
3|Page
, This reading is roughly double the level of TDS in mg/l as CaCO₃
What is steam purity? - Answers -It refers to the amount of contamination in the steam which
can be a liquid, solid or vapour. Steam purity is reported as the solids content. It is not to be
confused with steam quality, which is the amount of moisture in the steam.
What is carryover? - Answers -It is any solid, liquid or vaporous contaminant that leaves a boiler
along with the steam.
What does the steam purity need to be for use in a turbine? - Answers -A steam purity of 0.03
mg/L of TDS is necessary to prevent deposits.
What is the name of the sampling nozzles for steam purity? What are some details about it? -
Answers -It is called an isokinetic sampling nozzle. It is designed to take a representative sample
across the diameter of the pipe. The sample point is as far as possible from a source of
disturbance and has at least 10 diameters of straight pipe ahead of the sample location. For
pipes 152.5 mm and smaller, one nozzle is used, but for sizes 152.5 mm and larger, two nozzles
are used.
The preferred locations are listed in order:
1) Vertical pipe with downward steam flow
2) Vertical pipe with upward steam flow
3) Horizontal pipe with vertical nozzle
4) Horizontal pipe with horizontal nozzle
4|Page
UPDATED QUESTIONS AND VERIFIED 100% SOLUTIONS
(2026/2027) GRADE: A+|STATUS: GUARANTEED PASS
What is a heavy metal? - Answers -Any metallic element that has a relatively high density and is
toxic at low concentrations.
Mercury, cadmium, arsenic, chromium, thallium, and lead.
How is lead removed from water? - Answers -Because lead remains suspended rather than
dissolved, it is easily removed by filtration.
How is phosphate removed from water? - Answers -Phosphate can be precipitated at a pH over
10.0 with alum, sodium aluminate, or ferric chloride.
How is zinc removed from water? - Answers -It is removed by lime softening or by cation
exchange.
How is chromium removed from water? - Answers -It can be reduced by filtration and anion
exchange.
1|Page
,How is nickel removed from water? - Answers -It can be precipitated or removed by cation
exchange.
How are suspended solids removed? - Answers -They are removed by coagulation and
sedimentation, followed by filtration. The water must be free of suspended solids before it is
further purified in the demineralization section of the plant.
At what operating pressure must the sodium ions be removed? - Answers -Above 4000 kPa
Name some common oxygen scavengers - Answers -- Sodium sulphite
- Hydrazine
- Hydroquinone
- Ethyl ketoxime
At saturation temperature, all gases are - Answers -in free form.
What are the metal concentrations in a cooling tower, in comparison to make-up water? -
Answers -Due to the partial evaporation of the water in the cooling tower, the water may have
10 - 15 cycles of concentration (or 10 -15 time more).
What is the time limit for stocking reagents? - Answers -The maximum stock is often limited to a
six months supply
2|Page
,What is an indicator? - Answers -It is a solution that exhibits a change in colour when a very
small quantity is dissolved in a sample of water whose acidity or alkalinity is within a specific
range.
They are organic compounds with complex formulae and are themselves weak acids or alkalis.
Phenolphthalein, methyl orange solution, starch solution, pH indicator solution.
What is a reagent? - Answers -It is a substance that is used to produce specific reactions with
constituents of water that require measurement.
What does NTU stand for? - Answers -Nephelometric Turbidity Unit
What chemical is common for inhibiting embrittlement in boilers? - Answers -Sodium nitrate is
common for boilers up to 6700 kPa.
At higher pressures, coordinated phosphate/pH control is the usual internal treatment.
What is a mho? - Answers -A mho is a unit of electrical conductivity which is the reciprocal of an
ohm, the unit of electrical resistivity.
1 mho = 1/ohm
3|Page
, This reading is roughly double the level of TDS in mg/l as CaCO₃
What is steam purity? - Answers -It refers to the amount of contamination in the steam which
can be a liquid, solid or vapour. Steam purity is reported as the solids content. It is not to be
confused with steam quality, which is the amount of moisture in the steam.
What is carryover? - Answers -It is any solid, liquid or vaporous contaminant that leaves a boiler
along with the steam.
What does the steam purity need to be for use in a turbine? - Answers -A steam purity of 0.03
mg/L of TDS is necessary to prevent deposits.
What is the name of the sampling nozzles for steam purity? What are some details about it? -
Answers -It is called an isokinetic sampling nozzle. It is designed to take a representative sample
across the diameter of the pipe. The sample point is as far as possible from a source of
disturbance and has at least 10 diameters of straight pipe ahead of the sample location. For
pipes 152.5 mm and smaller, one nozzle is used, but for sizes 152.5 mm and larger, two nozzles
are used.
The preferred locations are listed in order:
1) Vertical pipe with downward steam flow
2) Vertical pipe with upward steam flow
3) Horizontal pipe with vertical nozzle
4) Horizontal pipe with horizontal nozzle
4|Page
