Chapter 13
UTILITY SYSTEMS
OBJECTIVES
▪ Describe the basic components of a steam system.
▪ Describe raw water and fire water systems.
▪ Describe boiler feed water treatment.
▪ Describe the basic components of a cooling water system.
CHAPTER 13 REVIEW QUESTIONS
1. Name two types of atmospheric tanks. Answer: Atmospheric tanks include cone roof and
umbrella roof. See chapter 3.
2. What is meant by “breathing” action? Answer: As a fixed roof tank is filled, the air or
vapor in the tank is expelled through the vent. As fluid is withdrawn from it, air enters
the tank through the vent to replace the volume of liquid being withdrawn. To a lesser
3. How does a flame arrestor work? Answer: In tanks that store flammable materials, the
vapor expelled by filling or heating is sometimes mixed with air (oxygen) in the proper
proportions to be ignited. To prevent the possibility of fire reaching the contents of the
tank, the vents are equipped with a flame arrestor. Flame arrestors are not designed to
4. Describe the purpose of a conservation vent. Answer: To regulate pressure during
5. Why are gas-blanketed tanks used? Answer: To prevent explosive mixtures from
6. Describe corrosion and the way’s process technicians prevent it. Answer: The process of
corrosion is a complex electro-chemical reaction that attacks metal. Corrosion prevention
7. Why do cooling towers need to be blown-down periodically? Answer: Blowdown is a
term used to describe the process where water is removed from the boiler system. As
8. Describe a fire water system. Answer: A fire water system includes pumps, tanks and
9. Describe boiler feed water treatment. Answer: Boiler feed water treatment is the process
by which suspended and dissolved solids are removed from the water. It is essential that
10. If it takes 1 Btu to raise the temperature of 1 lb of water 1ºF, how many Btus does it take
to convert 1 lb of water at 35ºF to steam? Answer: One pound of boiler feed water at 35ºF
11. What are some impurities found in natural water? Answer: Natural water may contain,
12. Why is the purity of boiler feed water critical to the operation and maintenance of the
system? Answer: The purity of boiler feed water is critical in the operation and
maintenance of this system. Water purity varies from site to site. Water hardness is
13. What is the maximum amount of suspended solids permitted in a boiler operating at over
14. What are coagulation and flocculation? Answer: Coagulation neutralizes the negative
15. What is the relationship between water softening and chemical precipitation? Answer:
Chemical precipitation uses a chemical to react with dissolved minerals in feed water to
16. How do anion resins and cation resins react with impurities in the water? Answer: Ion
exchange resins are used to remove electrically charged particles called ions from water.
17. Describe the operation of a deaerator. Answer: A deaerator is a device used to remove air
18. What is the justification for hooking nitrogen and instrument air systems together?
Answer: Do you agree? This control valve will close off if the instrument air header
pressure falls below 95 psig. It is important to maintain the instrument air system
19 Describe a flare system. Answer: Flare systems are used to remove safely excess
20. Describe the operation of a three-phase motor. Answer: Most of the motors in the plant
are the three phase induction type. Each of the pairs of poles is wound with one of the
21. What are natural gas systems used for? Answer: Natural gas is used to supplement the
fuel gas produced at a unit in order to meet furnace and boiler demands. Natural gas is
20. What is the primary function of a steam trap? Answer: Remove condensate from a steam
21. Describe an industrial sewer system. Answer: A plant sewer system collects all drains
22. Draw a simple sketch that shows how a refrigeration system operates. Answer: See
23. What are the basic components of a relief and flare system? Answer: A typical flare
system includes:
• a flare—a long, narrow pipe mounted vertically
