CFPS EXAM EXAMPLE: Gravity Tanks

Choose the correct answer:

CFPS EXAM EXAMPLE: connection between the public and private fire service mains

Choose the correct answer:

CFPS Exam Question Example (Fire pump suction under a positive pressure )

CFPS Exam Question Example ( Gravity tanks )

 

Q: What type of supply is considered acceptable as a single supply and is often made up of gravity tanks with adequate capacity and elevation?

 

a)       Secondary supply

b)      Cross-connected supply

c)       Dual supply system

d)      Primary supply

 Answer: D) Primary supply

FIRE PROTECTION HANDBOOK

15-64 SECTION 15 ■ Water Supplies for Fixed Fire Protection

Gravity Tanks

Gravity tanks of adequate capacity and elevation make a good primary supply and may be acceptable as a single supply.

CFPS Exam Question Example ( Size Of Street Mains supply )

Q:  What is the usual diameter considered inadequate and unreliable for street mains in the context of fire protection water supply?

 

a)       Less than 6 inches (152 mm)

b)      Less than 4 inches (102 mm)

c)       Less than 8 inches (203 mm)

d)      Less than 10 inches (254 mm)

 

Answer: A) Less than 6 inches (152 mm)

FIRE PROTECTION HANDBOOK

15-64 SECTION 15 ■ Water Supplies for Fixed Fire Protection

The size and arrangement of street mains and feeders from public water supplies are also important. Connections from large mains fed two ways or from two mains on a grid system may provide an excellent supply. Street mains less than 6 in. (152 mm) in diameter are usually considered inadequate and unreliable. Feeds from dead-end mains are also undesirable

CFPS Exam Question Example : Which types of detectors are used to sense radiant energy emitted from combustion reactions?

CFPS Exam Question Example 

    Which types of detectors are used to sense radiant energy emitted from combustion reactions?

 

A)      Flame detectors and spark/ember detectors

B)      Smoke detectors and heat detectors

C)      Carbon monoxide detectors and gas detectors

D)      Motion detectors and occupancy sensors

 

Answer: A) Flame detectors and spark/ember detectors

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Section 14

CHAPTER 2 ■ Automatic Fire Detectors 14-23

RADIANT ENERGY–SENSING FIRE DETECTORS.

Radiant energy–sensing devices sense the radiant energy (electromagnetic radiation) emitted as a by-product of the combustion reaction, which obeys the laws of optics. This includes radiation in the ultraviolet, visible, and infrared portions of the spectrum, emitted by flames or glowing embers. They are categorized as flame detectors and spark/ember detectors.

CFPS Exam Example question - Which of the following statements is true about UV detectors used for fire detection?

 

CFPS Exam Question Example 

Which of the following statements is true about UV detectors used for fire detection?

A) UV detectors are not sensitive to hydrocarbons or metals.

B)  UV detectors are sensitive to all types of fires except hydrocarbons.

C) UV detectors are sensitive to most fires, including hydrocarbons, ammonia, sulfur, hydrogen, hydrazine, and metals

D) UV detectors are not effective in detecting fires caused by middle and heavy fraction petroleum distillates.

Answer: c) UV detectors are sensitive to most fires, including hydrocarbons, ammonia, sulfur, hydrogen, hydrazine, and metals.

SECTION 14 

14-24 SECTION 14 ■ Detection and Alarm

Flame Detectors.

Ultraviolet Flame Detectors. 

The ultraviolet spectrum comprises wavelengths ranging from approximately 0.1µm to 0.35µm.  UV detectors typically use a vacuum photodiode Geiger-Muller tube to detect the ultraviolet radiation that is produced by a flame. The photodiode allows a burst of current to flow for each UV photon that hits the active area of the tube. When the number of current bursts per unit time reaches a set level, the detector initiates an alarm. A special control unit is required to monitor the count rates from UV detectors and initiate alarm.

UV detectors are sensitive to most fires, including hydrocarbons (liquids, gases, and solids), ammonia, sulfur, hydrogen, hydrazine, and metals such as magnesium. However, the smoke produced by combustion of middle and heavy fraction petroleum distillates is highly absorptive in the UV end of the spectrum, and this must be compensated for in system design if UV detectors are used