Low Pressure Boiler Test A with
Complete Questions and Answers
Name 3 types of fire protection systems - 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? - 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 - 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? - ANSWER-By throttling the
discharge valve or by changing the speed of the motor. Too much throttling may
require the installation of a bypass.
If the valve is closed completely or throttled too much the pump is will slowly
overheat.
What are the merits of the centrifugal pump? - 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. - 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 - 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? - ANSWER-To improve
circulation which reduces carryover.
What are the essential steps in putting a cold boiler on line with other operating
boilers? - 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 mechanical means? - ANSWER-When cleaning fire tubes a
knocker raps the inside of the tube, cracking the scale off the outside. When
cleaning water tubes a cutter head rotates inside, cutting. And crushing the scale.
Always keep the cutter head moving! A hydrostatic test should be preformed after
cleaning.
, What are pits, what causes them and how can you determine their depth. -
ANSWER-Pits are small hollow spots that could develop into holes. They are caused
by oxidation.
Make a plaster cast of the pit And surrounding plate. After the cast has set it will
show the depth of the pit.
Ultra/sound
Eddy current
X-ray
What is a fyrite analyzer? Where is it used? Why is it used ? - ANSWER-It is a flue
analyzer to determine the amounts of CO2 and O2 in flue gases. Combustion gases
are sampled from the last pass or the breaching.
It determines combustion efficiency.
Describe a gate valve and where it is used most often - ANSWER-A valve with a
wedge shaped gate which is raised or Lowered into a passageway. The wedge shape
tightens against the sides when closed. Little resistance to flow when open. Used to
isolate or shutoff flow.
How do you pipe a globe valve on a feed water system - ANSWER-
What is a pressure reducing valve ((PRV)) where is it used - ANSWER-The PRV
automatically reduces high pressure and maintains a lower delivery pressure. They
are used for heating systems, cookers, city water makeup, control air and gases or
oil to a boiler.
Explain the letters SWP and WOG found on the side of a valve. - ANSWER-SWP is its
maximum steam working pressure
WOG is the maximum water, oil, gas pressure the valve may be used for.
What precautions should be taken be removing a manhole cover - ANSWER-Make
sure the boiler is vented and drained
What is scale and what causes it? Why is it bad for a boiler - ANSWER-Scale is a
mineral sold in boiler water being deposited in the heating surfaces. It is caused by
Complete Questions and Answers
Name 3 types of fire protection systems - 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? - 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 - 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? - ANSWER-By throttling the
discharge valve or by changing the speed of the motor. Too much throttling may
require the installation of a bypass.
If the valve is closed completely or throttled too much the pump is will slowly
overheat.
What are the merits of the centrifugal pump? - 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. - 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 - 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? - ANSWER-To improve
circulation which reduces carryover.
What are the essential steps in putting a cold boiler on line with other operating
boilers? - 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 mechanical means? - ANSWER-When cleaning fire tubes a
knocker raps the inside of the tube, cracking the scale off the outside. When
cleaning water tubes a cutter head rotates inside, cutting. And crushing the scale.
Always keep the cutter head moving! A hydrostatic test should be preformed after
cleaning.
, What are pits, what causes them and how can you determine their depth. -
ANSWER-Pits are small hollow spots that could develop into holes. They are caused
by oxidation.
Make a plaster cast of the pit And surrounding plate. After the cast has set it will
show the depth of the pit.
Ultra/sound
Eddy current
X-ray
What is a fyrite analyzer? Where is it used? Why is it used ? - ANSWER-It is a flue
analyzer to determine the amounts of CO2 and O2 in flue gases. Combustion gases
are sampled from the last pass or the breaching.
It determines combustion efficiency.
Describe a gate valve and where it is used most often - ANSWER-A valve with a
wedge shaped gate which is raised or Lowered into a passageway. The wedge shape
tightens against the sides when closed. Little resistance to flow when open. Used to
isolate or shutoff flow.
How do you pipe a globe valve on a feed water system - ANSWER-
What is a pressure reducing valve ((PRV)) where is it used - ANSWER-The PRV
automatically reduces high pressure and maintains a lower delivery pressure. They
are used for heating systems, cookers, city water makeup, control air and gases or
oil to a boiler.
Explain the letters SWP and WOG found on the side of a valve. - ANSWER-SWP is its
maximum steam working pressure
WOG is the maximum water, oil, gas pressure the valve may be used for.
What precautions should be taken be removing a manhole cover - ANSWER-Make
sure the boiler is vented and drained
What is scale and what causes it? Why is it bad for a boiler - ANSWER-Scale is a
mineral sold in boiler water being deposited in the heating surfaces. It is caused by
