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High Pressure Boilers 4th ed. ch 1-11 exams (minus graphical questions)

15 psi

A low pressure steam boiler has a maximum allowable working pressure (MAWP) of up to ___.

One boiler horsepower

The evaporation of 34.5 lb of water/hr from and at a feedwater temperature of 212°F

through the tubes

In a firetube boiler, the heat and gases of combustion pass ___.

in high or low pressure plants

A firetube boiler may be used ___.

a firetube boiler

Because of the large volume of water, the boiler most likely to cause a boiler explosion is ___.


A horizontal return tubular (HRT) boiler is a ___ boiler.


As steam pressure in a boiler increases, there is a corresponding increase in the ___.

a boiler explosion

A sudden drop in boiler steam pressure without a corresponding drop in boiler water temperature could result in ___.

heating surface

The part of a boiler that has the heat and gases of combustion on one side and water on the other side is known as the ___.


The comparison, or ratio, of heat supplied in fuel to heat absorbed by water is defined as ___ efficiency.

boiler heating surface

Baffles are designed to direct the gases of combustion so that they come into close contact with the ___.


The steam and water drum of watertube boilers is dished (concave) to eliminate the need for ___.


To increase the life of a furnace refractory, some watertube boilers are equipped with ___.

high ceilings, less floor space, and the use of staybolts

Vertical firetube boilers require ___.

around the tubes

In a watertube boiler, the heat and gases of combustion pass ___.


The ___ boiler has a large volume of water in relation to horsepower size.

a firetube boiler (high or low pressure)

Stays and braces are needed to prevent bulging in ___.


The ___ boiler was developed to provide steam at higher pressures.


The mud drum is the lowest part of the water side of a(n) ___ boiler.


Boiler plates and staybolts are subjected to ___ stress.

American Society of Mechanical Engineers (ASME)

Safety valve connections must be approved by the ___.

safety and efficiency

Boiler fittings are necessary for ___.

safety valve

The most important fitting on a boiler is the ___.

safety valve

To prevent failure from pressure over the MAWP, all steam boilers must be equipped with at least one ___.

prevent the boiler from exceeding its MAWP

A safety valve will ___.

pop open

Safety valves are designed to ___.

before the main safety valves are set to open

Superheater safety valves are set to open ___.

at least 75% of the popping pressure

When testing a safety valve by hand, there must be ___.

safety valve manufacturer or manufacturer's authorized representative

Any repairs to a safety valve should be done by the ___.

qualified person who is familiar with the contruction and operation of a safety valve

The setting or adjusting of a safety valve should only be done by the ___.

an accumulation test is put on the boiler

If it is necessary to test the relieving capacity of a safety valve, ___.

pounds of steam per hour capable of discharging under a given pressure

The relieving capacity of a safety valve is measured in ___.

reduce turbulence in the gauge glass to get a more accurate reading of the water level in the boiler

The main purpose of a water column is to ___.

a secondary means of determining water level in a boiler.

Try cocks are ___.

using the try cocks

When replacing a broken gauge glass, the water level is checked by ___.

once a shift

The water column and gauge glass should usually be blown down ___.

warn the operator of high or low water

A whistle valve is used to ___.

pounds per square inch

A steam pressure gauge is calibrated in ___.

high temperature of steam

A siphon protects the steam pressure gauge from ___.


The pressure at the base of a vertical foot of water is ___ psi.

highest part of the steam side of the boiler

The boiler vent is located at the ___.

there is 10 to 15 psi of steam pressure on the boiler

The boiler vent is open when warming up a boiler until ___.

changing the direction of the steam flow

Steam separators work on the principle of ___.

upper part of the steam and water drum

The dry pipe is located in the ___.

boilers equipped with superheaters

Cyclone separators are used in ___.

its corresponding temperature and pressure

Saturated steam is steam at ___.

temperature increases with no increase in pressure

When steam is superheated the ___.

a continuous flow of steam

Superheater tubes are protected from warping or burning out by ___.

removed from boiler tubes for better heat transfer

Soot should be ___.

watertube boilers

Soot blowers are mainly found on ___.

cut through the boiler tubes in a very short period of time

Steam impinging on boiler tubes would ___.

highest part of the steam side of the drum

To ensure that moisture-free steam goes to the soot blower, the steam line to the soot blower must come off the ___

two main steam stop valves

Boilers in battery equipped with manhole openings must have ___ according to the ASME code.

Os&y gate

Main boiler stop valves must be ___ valves.

installed as close to the shell of the boiler as practical on the main steam line

The ASME code will allow an automatic nonreturn valve to be used as a main steam stop valve. If one is used it must be ___.

offer no restriction to the flow of steam

The main steam stop valves should be gate valves because they ___.

slightly lower than line pressure

When the boiler is equipped with hand-operated, main steam stop valves, to cut the boiler in on the line, the steam pressure on the incoming boiler should be ___.

closed, locked, and tagged.

When a boiler is being inspected, the two main steam stop valves are ___.

free-blowing drain should be open

During boiler warm-up, to remove any condensate trapped between the two boiler stop valves the ___.

expansion bends are used

During normal usage, the boiler main steam line expands and contracts. To allow for this ___.

two bottom blowdown valves

According to the ASME code, boilers operating at 100 psi or over must have ___.

opened first and closed last

When blowing down a boiler equipped with a quick-opening valve and a screw-type valve, the quick-opening valve is ___.

between the boiler and the slow-opening (screw-type) valve

If a quick-opening valve is used as a bottom blowdown valve, it must be located ___.

2 ½

The maximum size of the bottom blowdown line and the surface blowdown line is ___".

mud drum

Bottom blowdown lines on a watertube boiler are located on the ___.

boiler water analysis

The most accurate means of deciding the frequency of blowdown of a boiler is determined by a ___.

impurities that float on the surface of the water

Surface tension on the water in the steam and water drum is increased by ___.

blowdown tanks are used

To protect sewer lines from the high temperature and high pressure coming from the boiler blowdown lines, ___.

20,000 lb of water/hr

A boiler generating 20,000 lb of steam/hr must be supplied with at least ___.

in the open deaerator feedwater heater

Oxygen and other noncondensable gases are separated form the feedwater ___.

steam, feedwater, fuel, and draft

The four systems required to operate a steam boiler are ___.

one lb of water

In order to produce one pound of steam, it is necessary to evaporate ___.


Steam that has lost its heat and has turned back into water is ___.

be used for process work and heating

Steam is extracted from the turbine after it has passed through some of the turbine stages to ___

to the feedwater pump

Water from an open deaerating feedwater heater flows ___.

one steam and one electric feedwater

A safe and efficient boiler plant should include ___ pump(s).

passed through tubes to cause steam to condense, causing a vacuum

A surface condenser has water ___.


On the feedwater line near the boiler is a check valve and a stop valve. The valve closest to the shell of the boiler is the ___ valve.

volume of air passing through the venturi tube

On a boiler burning low pressure gas, the volume (amount) of gas burned is controlled by the ___.

allow one strainer to be cleaned without securing the boiler

On the fuel oil system, the purpose of the duplex strainers on the suction line between the tank and fuel oil pump is to ___.


A draft fan located between the boiler and chimney is used in a(n) ___ draft system.

more heat energy, thus producing more work

When steam is superheated it has ___.

reduces back pressure and steam flow rate

The vacuum on the exhaust side of the turbine ___.

above the feedwater pump(s)

The open feedwater heater is located ___.


No. ___ fuel oil must be heater in order to be pumped.

hand firing was inefficient in larger-sized boilers

Coal stokers were developed because ___.

can come in closer contact with the oxygen for complete combustion

Pulverized coal has the consistency of talcum powder so that it ___.

air or gases to flow

Draft is defined as a difference in pressure that causes ___.

high pressure

Air is mixed inside of the burner register in a(n) ___ gas system.

difference in temperature of a column of gas inside the chimney from a column of air outside the chimney

Natural draft is produced by a(n) ___.


Pulverized coal is burned in ___ in the furnace.

gas company representative

Gas leaks should be located and repaired by a ___.


Water weighs approximately ___ lb/gal.

maintain a water level in the feedwater heater if there are insufficient condensate returns

The automatic city water makeup valve found on an open feedwater heater is used to ___.

maintain a consistent water level in the boiler

The purpose of a feedwater regulator is to ___.

at the NOWL

Feedwater regulator sensing elements are located ___.

diameter of steam piston, diameter of water piston, and length of pump stroke

The sequence of three numbers found on the data plate attached to a reciprocating feedwater pump indicates the ___.


A(n) ___ draft fan must be used to overcome resistance caused by gases of combustion leaving the boiler when an economizer is used.

pump and the discharge valve

A reciprocating feedwater pump must have a safety relief valve located between the ___.

feedwater using gases of combustion

An economizer is used in large boiler plants to heat ___.

is converted into pressure

The theory of operation of a centrifugal pump is that the centrifugal force of a rotating element ___.

open or closed

Centrifugal feedwater pumps can be started with their discharge valves ___.

positive displacement pump

A turbine feedwater pump differs from a centrifugal feedwater pump in that it is a ___.

safety relief valve must be installed on the discharge line

To protect the turbine pump from excessive pressure, a(n) ___.

check valve can be repaired without taking the boiler off-line

The feedwater stop valve on the feedwater line is located closest to the shell of the boiler so that the ___.

the feedwater pump to become steambound

Water temperature that is too high in the open feedwater heater could cause ___.

oxygen pitting in the boiler

Water temperature that is too low in the open feedwater heater could cause ___.

when both superheated and saturated steam are needed, with a pressure-reducing station, and with feedwater addition to desuperheat the steam

A line desuperheater is typically used ___.

heat energy

Burning a fuel releases ___.

pressure buildup, which would cause an oil spill

A clogged vent line on a fuel oil tank being filled with fuel oil could result in a ___.

signs of sludge and water are evident in the tank

A high suction line on a fuel oil tank is used when ___.

circulate fuel oil during warm-up, return fuel oil that bypasses the burner, and return fuel oil from the relief valve

The purpose of the fuel oil return line is to ___.

live steam and air

In both steam and air atomizing burners, atomization is accomplished by ___.

manual reset valve

In a low pressure gas burner, a ___ shuts off the gas supply if a low water condition exists.

indicate gallons of fuel oil in the tank

The pneumercator is used to ___.

a large pressure drop

An indication of a dirty fuel oil strainer would be ___ across the strainer.

both the suction and discharge sides

Duplex strainers are found on ___ of the fuel oil pump.


Fuel oil heaters must be used when burning No. ___ fuel oil.

on the discharge side of

Fuel oil heaters must be protected from excessive fuel oil pressure because they are located ___ the fuel pumps.

a spinning cup and high velocity air

The rotary cup burner atomizes fuel oil using ___.

rotating, high pressure oil coming out of the plug or sprayer plate

In a pressure atomizing burner, atomization is accomplished by ___.

desired pressure at the burner

A gas pressure regulator is used to control the ___.

as an automatic gas shutoff valve

A solenoid valve is a direct-acting valve in the gas system and is used ___.

warm air is used

To prevent caking and to dry the coal entering the pulverizer, ___.

supply air for combustion

Blowers are used in a high pressure gas system to ___.

air damper, butterfly valve, and modulating motor and linkage

The air-to-gas ratio is maintained by a(n) ___.

Venturi effect

The amount of gas drawn into the air stream in a low pressure gas system is controlled by the ___.

more flexible operation

Boilers are equipped with a combination gas/fuel oil burner for ___.

anthracite or bituminous coal

The underfeed stoker can burn ___.

in suspension and on grates

Spreader stokers burn coal ___.

under and over the fuel bed

To achieve complete combustion in a spreader stoker, air is introduced ___.


The thickness of the fuel bed on a chain grate stoker is regulated by a coal ___.

in suspension

Pulverized coal burns ___.


The volume of gas to the burner in a high pressure gas system is controlled by a ___ valve.


In order to burn 1 lb of fuel, approximately ___ lb of air are needed.

inches or tenths of an inch of a vertical water column

Draft is measured in ___.

atmosphere; inside the boiler setting

Draft in the boiler is measured between two points such as the ___ and ___.

greater than

Pressure at the discharge side of a forced draft fan is ___ atmospheric pressure.

economizers and air heaters

To reduce the heat loss of flue gases going to the chimney, boilers are equipped with ___.

move up while the air goes down

The convection air heater employs a counterflow principle in which the gases of combustion ___.

the use of bypass dampers

Both air and flue gas temperatures are controlled by ___.

condensation on the gas side of the air heater

If the temperature of air entering the heater gets too low, it will cause ___.

using soot blowers

Air heaters must be cleaned to ensure good heat transfer by ___.

have a fairly constant steam load

Air heaters can most successfully be used in plants that ___.

a loss of air for combustion and lower boiler efficiency

If air supplied for combustion mixes with gases of combustion, it could lead to ___.

inches of water

A diaphragm draft gauge is calibrated in ___.

power-driven fans

Mechanical draft is produced by the ___.

forced or induced

Mechanical draft can be classified as ___.

height of the chimney

The amount of draft available in a natural draft system is dependent on the ___.

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