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33 Cards in this Set
- Front
- Back
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6 types of firetube boilers |
Horizontal Return Tubular (HRT) Economic Fire Box type Locomotive Fire Box type Scotch Marine Vertical Tubular Vertical Tubeless |
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Boiler tube attachment from best to worst |
-Rolled and Welded Tube -Rolled and Beaded Tube -Rolled and Flared |
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Boiler Stays |
Used to give the flat sections of a boiler additional strength, so that thicker plates are not needed |
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Beading |
prevents the tube end from being overheated and being burnt off |
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Firetube boiler advantages |
-low first cost -good steamer -economical |
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Above what pressure and temperature is a hot water boiler considered high pressure? |
160psi. or 250 Fahrenheit |
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Most likely areas for corrosion/leaks in a Vertical Tubular Boiker. |
1. Top of the lower part of tube sheet 2. Around Stays 3. At Waterline 4. Feedwater discharge 5. Water legs at bottom |
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A power boiler is a steam boiler that operates at pressures greater than ___psi, or a hot water boiler that operates above ____ and _____ . |
15 160psi. 250 degrees Fahrenheit |
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A supercritical boiler is a boiler that operates in excess of _____ or _______ . |
3206psia 705 degrees Fahrenheit |
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A boiler rated at 250 horsepower will be able to produce ______ pounds of steam per hour. |
1horsepower=34.5pounds of steam per hour 250×34.5 8625 PPH |
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A 450 horsepower hot water boiler has a rated output of _______ btu's per hour. |
1horsepower=33475 btu's per hour 450×33475
15063750 |
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The maximum voltage allowable on a control circuit is _____ volts. |
150 |
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In order to permit the water ina hot water heating system to expand without a corresponding increase in pressure, an ______ ______ must be used. |
expansion tank |
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Pressure relief valve on a hot water boiler must be at least ____ diameter and not more than ______ . |
3/4" 4 1/2" |
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A low pressure steam boiler must have an ASME __ stamp. |
H |
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The National Board of Boiler and Pressure Vessel Repair require an ___ stamp for companies that repair boilers. |
R |
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Water hammer is caused by quickly opening a ______ ______ . The sudden change in pressure and temperature on the connected piping may cause vibration, noise, or even pipe rupture. |
Steam Valve |
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The ratio of the boiler's heat output to it's heat input is ______ ______ . |
boiler efficiency |
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In ______ boilers, the water passes through the tubes, and the products of combustion pass around the tubes. |
watertube |
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What is the total force acting on a 2.5" pressure relief valve with a popping pressure of 150psi.? |
Total force=area×pressure Tf=2.5^2×.7854×150 736.31 lbs. |
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What is the popping pressure required to lift a 1 1/4" pressure relief valve with a spring pressure of 6500lbs.? |
Tf=A×P 6500=1.25^2×.7854×P 6500÷(1.25×1.25×.7854)=P 5296.66psi. |
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83 degrees Celsius=F |
F=(C×1.8)+32 F=(83×1.8)+32 181.4 degrees Fahrenheit |
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72 degrees Fahrenheit=C |
22.22 degrees Celsius |
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47 degrees Celsius=K |
C+273=Kelvin 47+273= 320 Kelvin |
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135 degrees Fahrenheit=Rankine |
F+460=Rakine 135+460= 595 Rankine |
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What is the absolute pressure on a boiler operating at 155psi.? |
155+14.7= 169.7psia. |
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_______ prevents the tube end from being overheated and being burnt off. |
Beading |
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A through stay differs from a diagonal stay in that it runs the _____ _____ of the boiler. |
entire length |
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A 20"x25" rectangular duct is replaced with a round duct. What is the minimum diameter of the round duct to provide the same cross sectional area? |
Aor=Aoc B×h=d^2×.7854 20×25=d^2×.7854 (20×25)÷.7854=d^2 SqRt((20×25)÷.7854)=d 25.23" |
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The Economic boiler was an improvement on the HRT boiler. The economic boiler has more ________ per square foot of floor space, it requires less ______ , and is easier to _______ as a single packaged unit. |
heating surface brickwork ship |
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A drypipe on a Scotch Marine boiler is used to remove ________ from the steam prior to leaving the boiler. |
moisture |
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Types of Scotch Marines |
Dry Back - combustion outside of shell Wet Back - combustion inside of shell |
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_____ _____ is made out of tin & is a alarm. It melts and whistles to alert of low water. |
Fusible Plug |
