Chapter Seventeen – PRESSURE HAZARDS
TRUE OR FALSE: Place T or F in the space provided.
_____1. A swift return to the surface from diving or decompression during
high-altitude ight may cause lung rupture.
_____2. Approximately 79% of the atmosphere is oxygen, with the other 21%
being nitrogen.
_____3. Pressure is the force exerted against an opposing uid or thrust
distributed over a surface.
_____4. To reduce pressure hazards, keep pressurized hoses as long as
possible.
_____5. Ultrasonic and X-ray waves are forms of destructive testing methods
used to detect cracks or leaks.
_____6. The least effective preventive measure for overcoming potential
pressure hazards is proper design.
_____7. Boyle’s law states that the product of a given pressure and volume is
constant with a constant temperature.
_____8. A boiler is an open vessel in which water is heated to form steam, hot
water, or high temperature water under pressure.
_____9. Boyle’s law states that the product of a given pressure and volume is
constant with a constant temperature.
_____10. Pressure is the force exerted against an opposing uid or thrust
distributed over a surface.
MULTIPLE CHOICE: Circle the letter before the correct answer.
1. Atmospheric pressure is usually measured using a:
A. Pressure vessel
B. Ultrasound meter
C. Barometer
D. Vacuum gauge
2. Which of the following situations may cause a vacuum?
A. Shock waves
B. Pressures below the atmospheric level
C. High-temperature water
D. Ultrasonic waves
3. Water vapor, although it is a gas, does not conform to:
A. Boyle’s law
B. OSHA standards
C. ASME codes
D. Dalton’s law
4. Which of the following is not an inert gas?
A. Helium
B. Argon
C. Oxygen
D. Neon
5. Safety hazards associated with boilers and other pressurized vessels
include the following except:
A. Human error
B. Mechanical errors
C. Design errors
D. Proper operator training
10. T
5. D
1. Against which references is pressure measured and how are these
references measured?
2. De?ne inspiration and expiration.
3. Explain Dalton’s law of partial pressures.
4. Does water vapor conform to Dalton’s law?
5. Briey discuss decompression sickness.
6. What do length of exposure, the bends, the chokes, and aseptic necrosis
of bone have in common?
7. De?ne hypoxia and hyperoxia.
8. Explain nitrogen narcosis.
9. Discuss altitude sickness.
10. What is the relationship between trapped gas effect and dysbarism?
11. What is the difference between destructive and nondestructive testing?
12. Briey explain proof pressures.
13. What causes vacuums?
14. Explain three ways to conduct nondestructive testing of pressure vessels.
15. What is the total decompression time for an employee who works for four
hours under pressure of 20 psig?