Ch. 10 - Boiler Connections,appurtenances, And Controls

Front 1

Minimum connections and appurtenances requirements by ASME Code

Back 1

-Pressure gauge and test connection

-Safety valve

-Blowdown valve

-Gauge glass

-Gauge cocks

-Main stop valve in steam line

-Stop and check valves in the feedline

Front 2

A water column is used to minimize__________in the gauge glass

Back 2

fluctuations

Front 3

The minimum size of the piping between the boiler and the water column is___.

Back 3

1"

Front 4

ASME code requires all boiler safety valves be stamped with a ____ stamp.

Back 4

"V"

Front 5

The device that allows for greater surface area for the steam to act upon, thus creating a popping action is called________ _________.

Back 5

Huddling Chamber

Front 6

The safety valve capacity must be sufficient to relieve all the steam that the boiler can generate at the ______ _______ _______ without allowing the pressure to rise more than _____ percent above the maximum allowable working pressure.

Back 6

maximum firing rate; 6

Front 7

Two or more safety valves are required on boiler with a heating surface in excess of ____ square feet, or elecric input of _____ KW.

Back 7

500; 500

Front 8

In lieu of a stop valve a __________ _______ may be used instead of the stop valve __________ to the boiler.

Back 8

Non-return valve; closest

Front 9

A slow opening blowdown valve must complete _____ turns between full open and full shut.

Back 9

5

Front 10

The accumulation of carbon dioxide in the condensate system produces __________ ________, which attacks and corrodes steam metal piping.

Back 10

carbonic acid

Front 11

A three element feedwater regulator senses _______ ______,________ ________,_________ _________.

Back 11

water level; feedwater flow; steam flow

Front 12

A device used to reduce the temperature of superheated steam to a lower desired temperature is a _________.

Back 12

desuperheater

Front 13

A pressure gauge installed 30 feet below the boiler drum reads 135psi. The actual pressure on the boiler is_____.

Back 13

Actual Pressure=Gauge pressure-(Vertical Distance/2.31)

Actual Pressure=135-(30/2.31)

Actual Pressure=135-12.98

Actual Pressure= 122.01psi.

Front 14

There is no ________ ______ ______ above the critical pressure, because water and steam have the same density.

Back 14

Latent heat of vaporization

Front 15

_________ _________ are used extensively in pulverized-fuel-burning plants in order to keep heat-absorbing surfaces free from soot and ash buildup.

Back 15

Soot blowers

Front 16

What is the total force acting on a 3" pressure relief valve with a popping pressure of 500psi.?

Back 16

FORMULA: Tf=AreaxPressure

TF = 3 x 3 x 500 x .7854

OR

Area=d^2x.7854

Area=3^2x.7854

Tf=(3^2x.7854)*500

Tf=3534.3lbs.

Front 17

Pressure gauge requirement

Back 17

-Must have a scale between 1 1/2 to 2 times the safety valve setpoint

-Must be at least 1/4" pipe size

-Must be able to isolate and attach a inspectors test pressure gauge

-Gauge on a steam boiler must be installed with a siphon

Front 18

Siphon types

Back 18

-Pigtail

-U-tube

Front 19

Pressure gauge correction formula

Back 19

Actual Pressure=Gauge Pressure-(Effective Water Leg/2.31)

Front 20

Safety Valve function and definition

Back 20

FUNCTION: a pressure relieving device that should be able to discharge all the steam the boiler can generate without allowing the boiler pressure to raise more than 6% above the MAWP or the safety valve setpoint (whichever is lowest)

Front 21

Water Column function

Back 21

Eliminates excessive fluctuations of the water level indication in the gauge glass

Front 22

Water Column requirements

Back 22

-Water column piping must be at least 1" diameter (water column to boiler)

-Brass piping is preferred up to 150psi (Brass less likely to corrode)

-Brass piping is required on Low Pressure Boilers in DC

-Where bends or turns are required, Cross T's are used instead of 90degree elbows

-Unused connections on Cross T's are used for internal inspection

-Lowest visible water level in the gauge glass should be 3" above the top row of boiler tubes

Front 23

Name plate data usually has .......

Back 23

-Manufacturers name or trademark

-Manufacturers model/serial/design number

-Size, in.

-Seat diameter, in.

-Set pressure

-Blowdown

-Discharge capacity

-ASME symbol/stamp

Front 24

When are 2 or more safety valves required

Back 24

-Heating surface greater than 500ft.^2

-Electric boiler greater than 500KW

-Boiler equipped with superheater

-Boiler equipped with reheater

-When the capacity of a single safety valve is not sufficient to relieve the capacity of the boiler

Front 25

Superheater safety valves requirement

Back 25

Boiler equipped with a superheater must have the superheater safety valve set lower than the boiler safety valve so that steam flow will always be maintained through the superheater tubes. The loss of flow through the superheater tubes will rapidly cause them to overheat and rupture.

Front 26

Sizing a relief valve on a pressure reducing station

Back 26

Relief Valve Capacity (RVC)=1/3*Orifice Capacity (OC)*Valve Size Pipe Area (VSPA)

Relief Valve Capacity (RVC)=1/2*Orifice Capacity (OC)*Bypass Pipe Area (BPA)

RVC= pounds of steam per hour

OC= lbs. steam/hr./in^2

VSPA= in^2

BPA= in^2

Front 27

Sizing a relief valve on a pressure reducing station Tables

pg.388

Back 27

memorize highlighted

Front 28

Safety Valve diagram pg. 363

Back 28

Memorize

Front 29

On a water column, the lowest visible level in the gauge glass should be ____" above the top row of the boiler tubes.

Back 29

"3"

Front 30

On a water column, where bends or turns require _______ that are used instead of ____ degree elbows.

Back 30

"Cross T's, 90"

Front 31

_________ protect a pressure gauge from steam pressure.

Back 31

"Siphons"

Front 32

A temperature sensor that measures the resistance of a platinum wire at different temperatures is a ________ ________ __________ .

Back 32

resistance temperature detector

Front 33

What is a "Safety Valve"?

Back 33

A pressure relief device used on a "steam or gas" system. Opens rapidly with a popping action.

(Capacity in lbs./hr)

Front 34

What is a "Relief Valve"?

Back 34

A pressure relief device used on a "water or liquid system." Opens gradually & proportionally to increasd in pressure.

(Capacity in btu's/hr)

Front 35

Loss of flow through the superheater will rapidly cause them to _______ & or _______.

Back 35

"overheat", "rupture"

Front 36

The minimum size of the blowdown line is ______inch, and the maximum size is ____ inches.

Back 36

3/4"

2 1/2"

Front 37

Prior to entering a confined space, the minimum amount of oxygen in the space ____ percent.

Back 37

19

Front 38

The operation of a black liquor boiler is known for its ________ , and recovery of ______ ______.

Back 38

steam generation; soda ashes

Front 39

A 300 horsepower hot water boiler has a rated output of ________ btu's per hour.

Back 39

1horsepower=33475 btu's per hour

300×33475

10042500

Front 40

Pressure relief valve on a hot water boiler must be at least ____ diameter and not more than _____.

Back 40

3/4"; 4 1/2"

Front 41

The ratio of the maximum fuel input rate and the minimum fuel input rate is known as the _________.

Back 41

turndown ratio

Front 42

Welding a flat strip of metal between the waterwall tubes is known as _____ wall construction.

Back 42

membrane

Front 43

Cogeneration plants sell ______ to local industrial plants, and _____ to the local utility.

Back 43

steam; electricity

Front 44

______ ______ boilers recover the heat in the exhaust from a gas turbine to produce useful steam.

Back 44

Waste heat

Front 45

A 500 horsepower boiler will be able to produce ______ pounds of steam per hour.

Back 45

1 horsepower = 34.5 pounds of steam per hour

500×34.5

17250

Front 46

A 32"x45" rectangular duct is replaced with a round duct. What is the minimum diameter of the round duct to provide the same cross-sectional area?

Back 46

Area of rectangle=b×h

Aor=32×45

Area of circle=d^2×.7854

1440=d^2×.7854

1440÷.7854=d^2

SQRT(1440÷.7854)=d

42.82"

Front 47

Boiler stop valves over 2" diameter must be ______-______-_____-_______.

Back 47

outside-stem-and-yoke.

Front 48

______ is the transfer of heat from a liquid flowing over the surface of a body.

Back 48

Convection

Front 49

The temperature of a liquid minus 32 is the ________ of the liquid.

Back 49

enthalpy

Front 50

A power boiler is a steam boiler that operates at pressures greater than ____ psi., or a hot water boiler that operates above _______ psi. or _____ degrees Fahrenheit.

Back 50

15; 160; 250

Front 51

The maximum voltage allowable on a control circuit is _____ volts.

Back 51

150

Front 52

Pressure relief valve on a hot water boiler must be at least ____ diameter and not more than ____ .

Back 52

3/4"

4 1/2"

Front 53

What is the total force acting on a 4" pressure relief valve with a popping pressure of 250psi.?

Back 53

Tf=A*P

A=d^2*.7854

Tf=(4*4*.7854)*250

Tf=3141.6lbs.

Front 54

What is the popping pressure required to lift a 3" pressure relief valve with a spring pressure of 7500lbs?

Back 54

Tf=A*P

7500=(3^2*.7854)*P

7500/(3^2*.7854)=P

P=1061.03psi.

Front 55

_______prevents the tube end from being overheated and being burnt off.

Back 55

Beading

Front 56

The minimum size of the blowdown line is ____ inch and the maximum size is ____ inches.

Back 56

3/4"

2 1/2"

Front 57

The operation of a black liquor boiler is known for its _______ generation, and recovery of ______ ______.

Back 57

steam

soda ashes

Front 58

______ ______ boilers recover the heat in the exhaust from a gas turbine to produce useful steam.

Back 58

Waste heat

Front 59

Welding a flat strip of metal between the waterwall tubes is known as _____ wall construction.

Back 59

membrane

Front 60

On HRT boilers, the shell is pitched 1 to 2 inches towards the back of the boiler to produce a more effective ______ _______ of the boiler.

Back 60

bottom blowdown

Front 61

The ratio of the boiler's heat output to its heat input is ______ ________.

Back 61

boiler efficiency

Front 62

A supercritical boiler is a boiler that operates in excess of ______ psia or ______ degrees Fahrenheit.

Back 62

3206

705

Front 63

_______ btu's per hour output is one boiler horsepower.

Back 63

33475

Front 64

A low pressure steam boiler must have an ASME ____ stamp.

Back 64

H

Front 65

A boiler horsepower is the evaporation into dry saturated steam of ____ pounds per hour from and at 212 degrees Fahrenheit.

Back 65

34.5

Front 66

The general classification of superheaters includes ________ and ________ types, depending on where the heat is absorbed.

Back 66

convection

radiation

Front 67

A temperature sensor that measures the resistance of a platinum wire at different temperatures is a ________ _________ ________.

Back 67

resistance temperature detector

Front 68

The minimum size of the piping between the boiler and the water column is ___.

Back 68

1"

Front 69

The device that allows for greater surface area for the steam to act upon, thus creating a popping action is called a ________ ________.

Back 69

huddling chamber

Front 70

A slow opening blowdown valve must complete ____ turns between full open and full shut.

Back 70

5

Front 71

The last form of over-pressure protection on the boiler, prior to lifting the safety valve is the _______ ________ _________.

Back 71

High Limit Control

Front 72

The minimum size for the connection between the gauge glass and the water column is ___.

Back 72

1/2"

Front 73

When using a lift lever to manually test a safety valve, the boiler pressure must be at least ____ percent of the safety valve setpoint.

Back 73

75

Front 74

For a company to make qualified repairs to a safety valve they must have a ____ stamp.

Back 74

VR

Front 75

A 24"x30" rectangular duct is replaced with a round duct. What is the minimum diameter of the round duct to provide the same cross sectional area?

Back 75

Area of rectangle

AR=Base x Height

Area of circle

A=d^2*.7854

24×30=d^2*.7854

24*30/.7854=d^2

SqRt (24*30)/.7854=d

d=30.28"

Front 76

On order for a Black Liquor boiler to sustain combustions, the liquor must contain over _____ percent solids.

Back 76

58

Front 77

__________ tubes are used to protect the refractory in the boiler.

Back 77

Waterwall

Front 78

ASME code requires all boiler safety valves be stamped with a ____ stamp.

Back 78

V

Front 79

How many BTU's are required to raise the temperature of 5 pounds of water from 50 degrees Fahrenheit to 200 degrees Fahrenheit?

Back 79

200-50=150

150*5=

750 btu's

Front 80

A pressure gauge installed 30 feet below the boiler drum reads 135psi. The actual pressure on the boiler is ____.

Back 80

Actual Pressure=Gauge Pressure - (effective water leg / 2.31)

Actual Pressure= 135 - (30 / 2.31)

Actual Pressure = 122.01 psi.

Front 81

Prior to manually testing a safety valve, the boiler pressure should ____ percent of setpoint.

Back 81

75

Front 82

A reciprocating pump has a water cylinder that is 15" diameter and 30" long. The plunger in the cylinder strokes 7/8 the length of the cylinder. What is the volume of water displaced with each stroke of the plunger?

Back 82

Area of Circle = d^2 * .7854

Volume of cylinder = Area of Circle * Length

Water displaced = Volume of cylinder * stroke length

Area of Circle = 15^2 * .7854

Volume of cylinder = (15^2 * .7854) * 30

Water displaced = (15^2 * .7854) * 30 * (7/8)

4638.77 in.^3

Front 83

A 4" pressure reducing valve has 1 1/2" bypass line. The inlet pressure is 125psi and the outlet pressure is 15psi. The safety valve on the discharge should be rated for ____ pounds per hour.

Orifice Capacity = 7200 PPH/in^2

Valve Size Pipe Area = 12.73 in^2

Bypass pipe area = 2.04 in^2

Back 83

Relief Valve Capacity (RVC) = 1/3 * Orifice Capacity (OC) * Valve Size Pipe Area (VSPA)

Relief Valve Capacity (RVC) = 1/2 * Orifice Capacity (OC) * Bypass Pipe Area (BPA)

RVC = 1/3 * OC * VSPA

RVC = 1/2 * OC * BPA

RVC = 1/3 * 7200 * 12.73

RVC = 30552 PPH

RVC = 1/2 * 7200 * 2.04

RVC = 7344 PPH

Safety Valve on the discharge should be rated for 7344 pounds per hour.