To minimize corrosion in a steam boiler, the P-alkalinity of the boiler water should be maintained ...

To minimize corrosion in a steam boiler, the P-alkalinity of the boiler water should be maintained between
  _____.
 
  a. 50 and 100 ppm
  b. 100 and 200 ppm
  c. 200 and 300 ppm
  d. 300 and 700 ppm

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[Ques. 2] What type of hardware is used to prevent gears and pulleys from spinning on a shaft?
 
  a. A key
  b. A cotter pin
  c. A retainer ring
  d. Blind rivet

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[Ques. 3] Flexible duct connectors are commonly used with _____.
 
  a. all ducts
  b. metal ducts
  c. round fiberglass duct
  d. rectangular fiberglass duct

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[Ques. 4] Before flanged ends are bolted together, they must first be _____.
 
  a. lubricated
  b. aligned
  c. torqued
  d. polished

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[Ques. 5] How are screws larger than 1/4 diameter sized?
 
  a. Gauge number
  b. Fractions of an inch
  c. Pitch number
  d. Threads per inch