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35 Cards in this Set
- Front
- Back
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Common shell and drum thickness range is a) 2 to 12 mm b) 6 to 250 mm c) 15 to 300 mm d) 100 to 1,000 mm e) 200 to 250 mm |
b) 6 to 250 mm |
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One or more steel plates rolled into cylindrical form and welded together, with the ends closed by means of end plates or heads,is called a a) combustion chamber b) packaged boiler c) steam or water drum d) steam header e) steam space |
c) steam or water drum |
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The circumferential seam of a riveted boiler shell utilized the a) lap joint, single or double riveted b) treble riveted butt joint c) double equal strap double riveted butt joint d) double unequal strap treble riveted butt joint e) always a single riveted lap joint |
a) lap joint, single or double riveted |
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Head-to-drum circumferential joints are usually a) double welded butt joints b) single welded edge joints c) fillet welded corner joints d) double welded tee joints e) fillet welded lap joints |
a) double welded butt joints |
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With regard to welding, heat treatment a) will increase the hardness of the material b) results in better penetration of the weld c) will relieve stresses in the material due to welding d) is done before the actual welding takes place e) is done to warm the welding machine before use |
c) will relieve stresses in the material due to welding |
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A non-destructive test on a boiler is a) a tensile test b) a bend test c) a shear test d) an X-ray test e) all of the above |
e) all of the above |
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Post weld heat treatment is a) to make the material hot enough for welding b) heating the material after welding c) to improve weld penetration d) to clean up the welded area e) done to reduce corrosion |
b) heating the material after welding |
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Tubes for high pressure service are usually a) resistance welded construction b) roll and pierce construction c) lap welded construction d) flared into the drum or tubesheet e) of 2 metre maximum length |
b) roll and pierce construction |
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A tube expander is used to a) break loose scale in the tube b) break loose scale outside the tube c) expand and flare the tube d) bead the tube e) expand the entire tube |
c) expand and flare the tube |
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The flat surfaces which require staying in a firetube boilerare the tubesheets, waterlegs, and a) furnace tubes b) flue gas baffles c) uptakes d) crown sheets e) access doors |
d) crown sheets |
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Boiler stays a) are used to support flat surfaces in a boiler b) are mostly used in water tube boilers c) have to be replaced every two years d) are used for hot water heating boilers only e) are made of hollow tubes |
a) are used to support flat surfaces in a boiler |
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A major force which acts to hold a manway door in place during boiler operation is a) the bolt b) the combination of bolt and yoke c) pressure within the boiler d) the manway gasket e) the yoke |
c) pressure within the boiler |
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A boiler nozzle attachment a) can be found in the area of the burner b) is always installed vertically c) allows a connection for the uptake d) is used for steam cleaning the fireside e) nearly always accommodates a valve or fitting |
e) nearly always accommodates a valve or fitting |
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Manholes are a) installed on all boilers b) provided for inspection purposes c) always circular in shape d) installed on fossil fired boilers only e) always oval in shape |
b) provided for inspection purposes |
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A Morison furnace is a) found in electric boilers b) found in locomotive boilers c) found in watertube boilers d) found in firetube boilers e) a ring-reinforced type furnace |
d) found in firetube boilers |
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Internal furnaces are a) mostly used to superheat the steam b) contained within the windbox of a boiler c) used to increase the strength of the drum d) used for oil firing only e) contained within the shell of the boiler |
e) contained within the shell of the boiler |
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With a bottom-supported boiler, the steam drum is usually2 a) a cross-drum configuration b) supported by an overhead girder arrangement c) supported by the watertubes d) supported by piers e) placed below the centreline of the unit |
c) supported by the watertubes |
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Boilers supported from the top a) are mostly package boilers b) are free to expand vertically c) can only be used on small units d) are usually not of the large water tube type e) can only use straight tubes |
b) are free to expand vertically |
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Three types of furnace water-walls are the tangent tube,welded fin, and a) flat stub b) corrugated c) refractory backed d) flat stud e) metal lath |
d) flat stud |
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In early boilers furnace walls were constructed of brick. Today this method has been replaced by the use of a) baffles b) steel casing c) tubes to form the furnace walls d) plastic insulation e) block insulation |
c) tubes to form the furnace walls |
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UNIT 12 DONE. TIME FOR UNIT 13!! ( BOILER FITTINGS) |
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Notes from plant theory class |
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What's thickness of the Shells and drums and how are they fabricated? |
6mm to 250mm (1/4inches to 10inches) Steel plates rolled and welded together |
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Two basic types of welds |
Groove weld and butt weld |
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Time required for preheating viewboiler |
150psi = 1.5hours to preheat |
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The thickness of the shell or drum is dependent on the design operating ______ of the boiler and the _______ of the tube or drum? |
Pressure, diameter. |
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There are five main types of welded joints. Name three. |
Butt joint,Lap joint,Corner joint,Tee joint,Edge joint |
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What is the first pass of a groove weld in a butt joint called? |
Root |
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Why do you preheat and postweld heat metal when you are going to weld it? |
Stress relief |
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What would a tapered mandrel be used for? |
Expand the tube ends into the tube holesin the drum or sheet. |
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What do stays do? Name two types. |
Support large flat surfaces to prevent it from bulging under pressure. Types of stays are diagonal, longitudinal/through stays and staybolts. |
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Why is a manhole cover elliptical? |
Ease of entry –but, most important, so as to be able to remove the manhole |
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The boiler will fall over if we don‟t hold it up. How are two ways we do that? |
Top/Bottom supported |
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Boiler construction is largely the science of joining metal plates, ____________ and _____________ ? |
Tubes and pipes |
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Waterwall boilers use tubes as the main furnace „walls‟. Gases could leak out, but don‟t because.... Why? Name two ways gas is kept inside a boiler. |
Walls of tubes –tangential water wall tubes and fin tubes, or also flat stud tube wall. |
