Low Pressure Boiler Test A Exam
Questions And Answers
Name 3 types of fire protection systems - - correct answer ✅Dry
sprinkler system, dry chemical system, halon system, inergen, FE-
13, FM200, deluge, elecrronic alarm, wet charged.
When operating a pump under 200 f what kind of seals do you use?
Will there be any leakage and why? - - correct answer ✅Soft
metallic packing or mechanical seals. Mechanical seals should not
leak, but with soft packing there will be minimal leakage to cool and
lubricate the packing and shaft.
Two types of centrifugal pumps and describe their differnces - -
correct answer ✅In a volute pump the impeller rotates in a casing
of spiral design. The casing is designed to enclose the outer
extremity of the impeller. The volute chamber changes velocity
head into pressure head.
In a turbine pump the impeller is surrounded by diffusion rings
which take the place of the spiraling casing in the volute pump. The
quantity of water depends on the size of the impeller and it's speed
How do you adjust the flow rate of a centrifugal pump? What
would happen if the discharge valve was closed on a centrifugal
pump? - - correct answer ✅By throttling the discharge valve or by
changing the speed of the motor. Too much throttling may require
the installation of a bypass.
,Low Pressure Boiler Test A Exam
Questions And Answers
If the valve is closed completely or throttled too much the pump is
will slowly overheat.
What are the merits of the centrifugal pump? - - correct answer
✅Few moving parts, uniform flow, easy to control, high capacities,
dependable and long life.
Make a drawing of a centrifugal pump and explain how it works. - -
correct answer ✅The spinning impeller draws liquid into its center
and discharges from its outer edge. Either a volute shaped casing or
the diffusion rings direct the liquid toward the discharge converting
velocity energy to pressure head.
Define perfect, complete and incomplete combustion - - correct
answer ✅Perfect combustion l: burning all the fuel using the
theoretical amount of air
Complete combustion: burning all the fuel and using more than the
theoretical amount of air.
Incomplete combustion: when a portion of the fuel remains
unburned because of insufficient amounts of air.
Why is a row of tubes sometimes left out of an HRT boiler? - -
correct answer ✅To improve circulation which reduces carryover.
, Low Pressure Boiler Test A Exam
Questions And Answers
What are the essential steps in putting a cold boiler on line with
other operating boilers? - - correct answer ✅Blowdown gauge
glass and water column
Check operation of feedwater valves and pumps
Open the vent on the boiler drum
Start the burner on low manual fire.
Test the flame scanner
Test the low water cutoff
When boiler pressure starts to build close the vent
Open the equalizing line around the header valve to warm the
header
Open header valve drain and non-return valve drain
When the header is hot open the header valve and close the drain.
When the boiler pressure is 80% of header pressure unscrew the
hand wheel on the non-return valve and close the drain
When boiler pressure equals header pressure put the controls in
automatic
How do you mechanically clean the waterside of a boiler tubes and
what precaution should be taken? What test should be down after
the cleaning? How are boiler tubes cleaned other than with
Questions And Answers
Name 3 types of fire protection systems - - correct answer ✅Dry
sprinkler system, dry chemical system, halon system, inergen, FE-
13, FM200, deluge, elecrronic alarm, wet charged.
When operating a pump under 200 f what kind of seals do you use?
Will there be any leakage and why? - - correct answer ✅Soft
metallic packing or mechanical seals. Mechanical seals should not
leak, but with soft packing there will be minimal leakage to cool and
lubricate the packing and shaft.
Two types of centrifugal pumps and describe their differnces - -
correct answer ✅In a volute pump the impeller rotates in a casing
of spiral design. The casing is designed to enclose the outer
extremity of the impeller. The volute chamber changes velocity
head into pressure head.
In a turbine pump the impeller is surrounded by diffusion rings
which take the place of the spiraling casing in the volute pump. The
quantity of water depends on the size of the impeller and it's speed
How do you adjust the flow rate of a centrifugal pump? What
would happen if the discharge valve was closed on a centrifugal
pump? - - correct answer ✅By throttling the discharge valve or by
changing the speed of the motor. Too much throttling may require
the installation of a bypass.
,Low Pressure Boiler Test A Exam
Questions And Answers
If the valve is closed completely or throttled too much the pump is
will slowly overheat.
What are the merits of the centrifugal pump? - - correct answer
✅Few moving parts, uniform flow, easy to control, high capacities,
dependable and long life.
Make a drawing of a centrifugal pump and explain how it works. - -
correct answer ✅The spinning impeller draws liquid into its center
and discharges from its outer edge. Either a volute shaped casing or
the diffusion rings direct the liquid toward the discharge converting
velocity energy to pressure head.
Define perfect, complete and incomplete combustion - - correct
answer ✅Perfect combustion l: burning all the fuel using the
theoretical amount of air
Complete combustion: burning all the fuel and using more than the
theoretical amount of air.
Incomplete combustion: when a portion of the fuel remains
unburned because of insufficient amounts of air.
Why is a row of tubes sometimes left out of an HRT boiler? - -
correct answer ✅To improve circulation which reduces carryover.
, Low Pressure Boiler Test A Exam
Questions And Answers
What are the essential steps in putting a cold boiler on line with
other operating boilers? - - correct answer ✅Blowdown gauge
glass and water column
Check operation of feedwater valves and pumps
Open the vent on the boiler drum
Start the burner on low manual fire.
Test the flame scanner
Test the low water cutoff
When boiler pressure starts to build close the vent
Open the equalizing line around the header valve to warm the
header
Open header valve drain and non-return valve drain
When the header is hot open the header valve and close the drain.
When the boiler pressure is 80% of header pressure unscrew the
hand wheel on the non-return valve and close the drain
When boiler pressure equals header pressure put the controls in
automatic
How do you mechanically clean the waterside of a boiler tubes and
what precaution should be taken? What test should be down after
the cleaning? How are boiler tubes cleaned other than with
