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30 Cards in this Set
- Front
- Back
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Feedwater for a high-pressure boiler should be __________ water. |
softened |
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The regenerant used to regenerate a cation exchanger in a demineralized is ___________ acid. |
sulphuric |
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A normal operating pressure range for a deaerator is ______ kPa to ______ kPa. |
70 kPa - 100 kPa |
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Reasons to treat boiler water include:
• preventing _______ from forming on boiler surfaces • preventing ____________ of boiler metal • preventing sludge from depositing on boiler surfaces |
scale, corrosion |
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Which of the following is not a type of coagulant?
a) aluminium sulphate b) aluminium hydroxide c) sodium aluminate d) calcium chloride |
d) calcium chloride |
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If the feedwater is neutral, its pH value is _____. |
7 |
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Filters are used for __________ water treatment. |
external |
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Dissolved gases may be removed from feed water by __________ the boiler feed water to its ____________ point. |
heating, boiling |
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The ___________ inside a water softener is used to exchange sodium cations for calcium and magnesium cations. |
zeolite |
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Water filters must be cleaned by ____________ the filter media. |
backwashing |
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Dissolved solids in raw water (can or cannot) be removed with filters. |
cannot |
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Hot lime-soda softeners can treat _________ quantities of water than the cold process type. |
larger |
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Coagulants added to water will remove ________ particles more readily. |
fine |
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The regenerant used to regenerate a cation demineralizer is __________ acid. |
sulphuric |
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Corrosion products in feedwater can cause ________ failure. |
tube |
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Two common chemicals used for deaeration are Na2SO3 (sodium sulphite) and _________. |
N2H4 (hydrazine) |
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Excess sulphite is necessary to prevent ___________. |
pitting |
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Excess phosphate is necessary for the prevention of _________. |
scale |
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When conducting a total dissolved solids (TDS) test, the impurity which has a high conductivity and must be neutralized is the ___________ alkalinity. |
hydroxide |
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Chemicals are usually fed to a boiler with a ________ positive displacement pump. |
small |
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Which of the following is an operating problem that could occur as a result of improper boiler water treatment?
a) caustic embrittlement of the boiler metal b) foaming of the boiler water c) sludge deposits d) all of the above |
d) all of the above |
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A normal temperature for the sample on the exit of a sample cooler is ____˚C. |
24˚C |
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Carbon dioxide causes return line corrosion and may be the result of _____________ decomposition. |
bicarbonate |
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The conductivity meter is used to measure the _______. |
TDS (total dissolved solids) |
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The water in a boiler should be kept:
a) acidic b) neutral c) alkaline d) depends on the type of boiler |
alkaline |
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The two types of closed chemical feeders are:
a) sequential b) bypass c) graduated d) gravity drip |
b) bypass d) gravity drip |
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Before conducting a test, the boiler water sample should be ___________. |
cooled |
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The ___________ type of chemical is fed into a boiler system using a gravity drip feeder. |
powdered |
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Sodium sulfite will prevent corrosion due to ___________ in the boiler water. |
oxygen |
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Titrating is done with a __________. |
reagent |
