MECHANICS FIRE FIGHTING

L | C | LOGISTICS

PLANT MANUFACTURING AND BUILDING FACILITIES EQUIPMENT

Engineering-Book

ENGINEERING FUNDAMENTALS AND HOW IT WORKS

September 2014

Expertise in Process Engineering Optimization Solutions & Industrial Engineering Projects Management 

Supply Chain Manufacturing & DC Facilities Logistics Operations Planning Management

Fire Fighting

A fire sprinkler system is an active fire protection measure, consisting of a water supply system, providing adequate pressure and flow rate to a water distribution piping system, onto which fire sprinklers are connected

A glass bulb type sprinkler head will spray water into the room if sufficient heat reaches the bulb and causes it to shatter. Sprinkler heads operate individually. Note the red liquid alcohol in the glass bulb

Fire Fighting

In a standard wet-pipe sprinkler system, each sprinkler activates independently when the predetermined heat level is reached. Because of this, the number of sprinklers that operate is limited to only those near the fire (in reality, normally one or two will activate), thereby maximizing the available water pressure over the point of fire origin. This also minimizes the water damage to the building.

A typical sprinkler used for industrial manufacturing occupancies discharge about 75-150 litres/min (20-40 US gallons/min). However, a typical Early Suppression Fast Response (ESFR) sprinkler at a pressure of 50 psi (340 kPa) will discharge approximately 100 US gallons per minute (0.0063 m3/s)

A sprinkler activation will do less damage than a fire department hose stream, which provide approximately 900 liters/min (250 US gallons/min)

Fire Fighting

To prevent the water supply pressure from forcing water into the piping, a deluge valve is used in the water supply connection, which is a mechanically latched valve. It is a non-resetting valve, and stays open once tripped

Activation of a fire alarm initiating device, or a manual pull station, signals the fire alarm panel, which in turn signals the deluge valve to open, allowing water to enter the piping system. Water flows from all sprinklers simultaneously

The type of fire alarm initiating device is selected mainly based on the hazard (e.g., smoke detectors, heat detectors, or optical flame detectors). The initiation device signals the fire alarm panel, which in turn signals the deluge valve to open

Analog addressable detectors provide information about the amount of smoke in their detection area, so that the fire alarm control panels can decide itself, if there is an alarm condition in that area

Fire Fighting

All smoke detectors must be hooked directly to the electrical wiring, be interconnected and have a battery backup

In addition, smoke detectors are required either inside or outside every bedroom

Smoke detectors on the outside will detect fires more quickly, assuming the fire does not begin in the bedroom

but the sound of the alarm will be reduced and may not wake some people

Some areas also require smoke detectors in stairways, main hallways and garages

Fire Fighting

A heat detector is a fire alarm device designed to respond when the convected thermal energy of a fire increases the temperature of a heat sensitive element

The most common fixed temperature point for electrically connected heat detectors is 136.4°F (58°C) and 117°F (47°C

Hydraulic calculation is the fire safety practice of calculating the flow of liquids through a medium (usually a piping network) to ensure that fires could be extinguished

for a Light Hazard office is .1/1500, " 0.1 GPM per square foot is required to fall from the fire sprinklers onto the fire over the most remote 1,500 square feet (140 m2) of area, which is the maximum expected size of a fire in this Light Hazard building area.“

for a warehouse type "big box" store that has higher flammability items stored on racks to twenty feet high is .6/2000. " 0.6 GPM per square foot is required to fall from the fire sprinklers onto the fire over the most remote 2,000 square feet

Fire Fighting

The water available is verified by means of a water flow test (opening a fire hydrant and recording the water pressures and gallons flow per minute).

A fire pump is a part of a fire sprinkler system's water supply and can be powered by electric, diesel or steam

The pump intake is either connected to the public underground water supply piping, or a static water source

A jockey pump is connected to a fire sprinkler system and is intended to maintain pressure in a fire protection piping system to an artificially high level so that the operation of a single fire sprinkler will cause a pressure drop which will be sensed by the fire pump automatic controller, causing the fire pump to start

Fire Fighting

A Fire Alarm Control Panel receives information from environmental sensors designed to detect changes

associated with fire, monitors their operational integrity and

provides for automatic control of equipment, and transmission of information necessary to prepare the facility for fire

The panel may also supply electrical energy to operate any associated sensor, control, transmitter, or relay

Fire Fighting

Alarm Also known as "Fire" or "General Alarm“ This indicator is lit when an alarm condition exists in the system, initiated by smoke detectors, heat detectors, sprinkler flow switches, manual pull stations, manual call points,

Along with the indicator on the panel, notification appliances, such as horns and strobes, are also activated, signaling a need to evacuate to building occupants

In an alarm condition, the fire alarm panel indicates where the alarm originated, and can be reset once the device which initiated the alarm is reset, such as returning the handle of a manual pull station to its normal position

Supervisory This signal indicates that a portion of the building's fire protection system has been disabled (such as a fire sprinkler control valve being closed and, consequently, a sprinkler tamper switch being activated), or, less frequently, that a lower priority initiating device has been triggered (such as a duct smoke detector).

the supervisory point may be latching, meaning the panel must be reset to clear the supervisory condition, or non-latching, meaning the indicator automatically goes out when the condition has cleared

Supervisory SwitchesThe nerve centers of a fire sprinkler system are the switches and valves that control the entire system

System Sensor offers a variety of choices for supervising system control valves

Regardless of valve type (outside screw valve monitoring and yoke, post indicator, butterfly, or non-rising stem gate valve),

Supervisory Switches models provide the peace of mind that comes from knowing that the system’s control valves are being monitored

PIBV (Post Indicator/Butterfly Valve) Supervisory Switch

Thank You

L | C | LOGISTICS

PLANT MANUFACTURING AND BUILDING FACILITIES EQUIPMENTEngineering-Book

ENGINEERING FUNDAMENTALS AND HOW IT WORKS

MECHANICS FIRE FIGHTING