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18 Cards in this Set
- Front
- Back
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What are the two types of electric boiler? |
A. Electrode type B. Immersion heater type |
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_______ needs to be added to the water in order for it to conduct electricity. |
Salt |
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Because an electrode type electric boiler is self regulating it doesn't need 1. 2. |
1. A low water cut off 2. High pressure limit switch |
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Electrode type boilers operate at volts up to _________ and power ratings up to_________. |
1. 16,000 volts 2. 30,000 Kw |
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Two disadvantages of the electric boiler are as follows. |
1. Electricity is usually more expensive. 2. Most designs are limited to pressures of 2100 kPa |
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Control of the immersion type boiler is accomplished by turning _______ on and off. |
Elements |
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The main part of the firetube boiler is ___________. |
The shell |
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Shells and drums are made of steel plates. The thickness of these plates vary from _______ to _______. |
6 mm to 250 mm |
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In the case of a watertube boiler, the heads are in a ______ shape rather than a _______ shape. |
Dished, flat |
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In the case of a firetube boiler, the heads are in a ______ shape rather than a _______ shape. They are called _________. |
Flat rather than dished Tubesheets |
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Five basic joints used when welding in boiler construction |
1. Butt joint 2. Corner joint 3. Tee joint 4. Lap joint 5. Edge joint |
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Which welding joint is primarily used in boiler construction? |
Butt joint |
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Two basic types of welds |
1. Groove weld (butt joint) 2. Fillet weld |
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During the welding processes ________ can build up in the metal. These stresses can be removed through ______ ________. |
Stress Heat treatment |
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Two types of rivited joints |
1. Lap joints 2. Butt joints |
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Three types of tube attachments in firetube boilers |
1. Expanded and beaded over 2. Expanded, beaded over and welded 3. Expanded, beaded over and grooved |
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An immersion electric boiler capacity can be as high as: 1) 5 000 kW 2) 16 000 kW 3) 1 500 kW 4) 2 100 kW 5) 30 000 kW
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3) 1 500 kW |
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The advantages of an electric boiler are: 1. More efficient 2. Does not need water treatment 3. Very compact 4. No fuel storage space required 5. No pollution 6. Does not need a safety valve A) 2, 3, 4, 6 B) 1, 3, 4, 5 C) 1, 2, 4, 5 D) 2, 3, 4, 5 E) 1, 2, 3, 6 |
B) 1, 3, 4, 5 |
