A) Semiconductor, catalytic element, or infrared absorption.
B) Spot type, beam type, or air sampling type.
C) Heat type, ionization type, or dual-sensor type.
D) Optical type, thermal type, or particle type.
Answer: A) Semiconductor, catalytic element, or infrared absorption.
CHAPTER 2 ■ Automatic Fire Detectors 14-23
CFPS Exam Question Example
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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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 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.
المتطلبات :
عندما تكون السقف من جهة واحدة أو كلا الجهتين لجدار الحريق مائلة نحو الجدار الحريق بميل يتجاوز 2 وحدة عمودية في 12 وحدة أفقية (2:12)، فيجب تحقيق بعض المتطلبات و هى تمديد جدار الحريق.
The capacity and pressure ratings of fire pumps must be adequate to meet flow and pressure demands consistent with water supply requirements for the property in question. Fire pumps are designed to provide their rated capacity with a safety factor built in (150 percent of rated capacity at 65 percent of rated pressure) to provide some protection in case of greater than-expected demand at the time of a fire.
The shape of the standard head discharge curve of a fire pump is determined by three limiting points: the shutoff, the rating, and the overload.
With the pump operating at rated speed and no flow, the total head of a horizontal centrifugal pump, vertical turbine pump, or an end-suction pump at shutoff must be between 100 and 140 percent of the rated head pressure at the 100 percent flow capacity.
The shutoff point represents the maximum allowable total head pressure. Otherwise, the pump would have a rising or convex characteristic curve. Such pumps are not listed. With a convex curve, there could be two flow points for one pressure.
At 150 percent of rated flow capacity, the total head pressure should not be less than 65 percent of the rated total head. The curve should pass through or above the overload point. Most fire pumps have curves with a small margin above the theoretical overload, and some models have a cavitation or “break” point in the curve just beyond overload.
These are required on the pump discharge line when the operation of the pump can result in excess pressure that would exceed the pressure rating of the fire protection system. The design of this device is very critical to the proper operation of the fire protection water supply. If the pump is oversized for flow and pressure, the main relief valve should not be used to limit the pressure and discharge excess quantities of water during the normal weekly run test and annual flow test. This is of particular importance in climates where there is freezing weather for a portion of the year. In these situations the designer should look further at other pump choices and optional drivers for the pump that will limit the discharge head. A good example is a variable-speed diesel engine or electric motor listed system.
