Summary of NBC 2016 Part 4 Fire and Life Safety

Summary of NBC 2016 Part 4 Fire and Life Safety 

Bureau of Indian Standards (BIS) is the National Standards Body of India established under the BIS Act 2016 for development of standards, marking and quality certification of goods and for matters connected therewith or incidental thereto.

The National Building Code of India 2016 (NBC 2016), a comprehensive building Code prepared by BIS, is a national instrument providing guidelines for regulating the building construction activities across the country.

Thus, the Code gives all the information required by the architect, engineer, structural engineer, construction engineer, services engineer and other professionals from the early stages of planning to translating the building on to terra firma. The comprehensive NBC 2016 contains 13 Parts some of which are divided into Sections and Subsections totalling 33 chapters.

Key Content - Fire and Life Safety

All buildings shall satisfy minimum requirements for safety of life from fire, smoke, fumes or panic arising from these or similar causes.

Classification of buildings based on occupancy

The city or area under the jurisdiction of the Authority shall be demarcated into distinct fire zones depending upon the existing layout, types of building construction, classification of existing buildings based on occupancy and expected future development of the city or area. Intermixing of hazardous occupancies should not be allowed in other zones.

1) Fire resistant walls, floors and compartments

• To limit the spread of fire

• No compromise for openings such as shafts, refuse chutes, vertical openings, etc.

2) Shafts

• To be provided with fire resistant rated inspection door for passage of building

services such as cables, electrical wires, telephone cables, plumbing pipes, etc

depending upon location.

3) Refuge area

• An area within the building for a temporary use during egress. It generally serves as

a staging area which is protected from the effect of fire and smoke.

4) Fire detection and firefighting installations

• These include fire alarm, fire extinguishers, hose reels, wet riser, down comer,

yard hydrants, sprinklers, deluge system, water spray, foam, water mist systems,

gaseous or dry powder system, water storage tanks and pumps, etc.

5) Means of egress

• Consists of three separate and distinct parts, that is, exit access, exit and exit discharge

• Exit access are working/functional areas

• Various types of exit access and exits are doorways, corridors and passageways, horizontal exits, internal staircases, exit passageways, external staircases and ramps.

6) Firefighting shafts

• With fire man talk back, fire door, wet riser, hose reel, signage showing floor plan and stairways and fire man’s lift

Fire prevention

Fire prevention is based on the following:

•        Occupancy

•        Fire zones

•        Types of construction

•        General requirement of all occupancies

•        Electrical installation

a.   Emergency power for fire and life safety system

b.   Substation

c.    Lightning protection

d.   Escape lighting and exit signage

e.   HVAC and smoke control

f.     Glazing

g.   Surface interior finish

h.   Fire Command Centre

•        Fire resistance rating of structural and non-structural elements updated

•        Fire resistance rating of service shaft and duct opening of 2 hours.                                 Inspection door and duct opening should have same resistance rating of  service shaft.

•        Facade protection and openable windows in facade shall have fire protection and smoke exhaust aspects

•        Compartment criteria of different occupancies and fire separating wall & floor partitions are modified

•        Provision of fire/smoke damper design more elaborated like provision of damper

A.   At the fire separation wall

B.   Where ducts/passage enter the vertical shaft

C.   Where the duct passes through floor

D.   At the inlet of supply air duct and return air duct of each compartment on every floor.

Glass facade

1. For fully sprinkler building having fire separation of 9 m or more, tampered glass in a non-combustible assembly with ability to hold the glass in position shall be provided
2. It shall be ensured that sprinklers are located within 60 cm and there is full coverage of glass. All the gaps between floor slab and facade assembly shall be sealed at all level by fire resistant sealant material of equal rating of floor slab to prevent fire and smoke propagation from one floor to another.
3. Openable panels shall be provided in each floor and shall be spaced not more than 10 m apart, measured along the external wall from the centre to centre of the access opening. Such opening shall be operable at a height between 1.2 m and 1.5 m from the floor in the form of openable panel (Fire Access Panel) not less than 1000 mm x 1000mm opening outward.

FIRE OPENABLE PANEL DO NOT OBSTRUCT IN  25 mm lettering in the inner side can also act as smoke exhaust at the time of distress.

Service Sector in Focus

Some important features considered in Hospitals

•        Each compartment shall be able to accommodate patients from adjoining compartment and Density Factor (Number of patient) area to be allotted 3.5 sq.m/person

•        Critical patients, incapable of self-preservation and physical impairment shall be housed within 30 m height

•        Other types of patient and occupancy like Nurses’ centre, Medical shop, Canteen, etc to be in between 30-45 m in height

•        Operation theatre, Delivery room, ICU, Recovery room shall have a separation with 2 hours of fire resistance rating

•        Passage width of aisles, corridor, ramp, etc shall be 2.4 m unobstructed through which patients are being moved and in case of inpatient width not less than 1.5

•        All exits from Hospital or Infirmary Section shall not be less than 2m

•        Minimum door width single/double occupancy shall be 1.25 m; for 3-5 patients, door width shall be 1.50 m; for more than 5 patients and patient evacuation bed (i.e. ICU) it shall be 2.0 m; for single/double doors, it shall be 1.5 m

•        Any sleeping accommodation or suite exceeding 100 sq.m in area, 2 no.s of access door leading to escape route, corridor, etc to be provided

•        Room designed for laboratory or like facility shall be limited to 100 sq.m in area for additional area coverage. Fire separation shall be done by 2 hours fire resistance.

•        A stretcher lift in the lift bank shall also act as a fireman lift

Life safety is based on:

•        General exit

•        Occupant load

•        Declaration of occupant load

•        Egress components

•        Smoke control of exit

•        Compartmentation

•        Smoke control above and below ground

•        Gas supply

•        Hazardous area

•        Fire detection

•        Fire drill

Safe electrical supply system

•        The electrical supplies towards the critical aspects of emergency power for fire and life safety addressed for respective system.

•        Power supply to the panel and distribution board be through fire proof enclosure or circuit integrity cable or through alternate route in the adjoining fire compartment is protected within the compartment of vulnerability and require location of the panel/distribution board feeding shall be in fire and safety zone and ensure supply of power to these system.

•        The high voltage electrical equipment safety including aspects of emergency and exit lighting of large and public assembly occupancies

•        HVAC system, smoke control and mitigation also to be taken care of with comprehensive approach towards compartmentation and spread of fire and smoke.

Life safety

•        To calculate the number of exit requirement with Density Factor

•        Exit Layout for better understanding of various aspects of means of egress, corridor, passageways, stair ways and exit

•        Provision for access control door, electromagnetic door, revolving door and turnstile (conditions to be fulfilled)

•        Provision of handrail at both sides of stairs and ramp width exceeding 1.5m

•        Internal stair width of residential building increased to 1250 mm from 1000 mm

•        External stairs width increased from 1250 mm to 1500 mm

•        Each fire rated door shall have a marking on the product of its certification. Door assembly parts like hinges, locks, panic bars, door closer and door viewer shall be certified.

•        Updated staircase pressurization requirement (Smoke control of exit) for lobbies & corridors

•        Smoke exhaust and pressurization of area below the ground floor

•        Requirement of smoke exhaust system having make up air system for the theatre and atrium

•        Smoke exhaust fan in the mechanical ventilation system shall be fire rated of 250 degrees centigrade for 2 hours (120 minutes)

•        Provision of smoke barrier and sprinkler around the opening for escalator

•        Requirement of display of occupancy load for assembly occupancy and call center.

Fire and Smoke Damper Requirements as per IBC

Fire & Smoke Damper Requirements as per IBC

According to the International Building Code (IBC), fire and smoke dampers are required in certain locations to prevent the spread of smoke and protect people and buildings from fire.

Fire dampers are installed in ducts passing through or in air outlet openings terminating at shaft walls, fire barriers (such as an occupancy separation wall, horizontal exit walls, corridor walls, corridor ceilings, floor-ceiling assemblies) and other fire resistance–rated assemblies as required by a building or life safety code and other applicable standards.  Under severe fire exposure, a duct may eventually collapse or significantly deform, creating an opening in the fire barrier. Fire dampers provide a method of protecting such penetrations and openings. Fire dampers must be inspected one year after installation and every four years after that. Hospitals are an exception, and must be inspected after one year and every six years.

Smoke damper’s primary function is to control the movement of smoke in dynamic air distribution systems, and they reduce the possibility of smoke transfer within ductwork or through wall openings. They are installed in ducts passing through, or air outlet openings terminating at, smoke barriers, shaft walls, horizontal exit walls, corridor walls, corridor ceilings, and other barriers designed to resist the spread of smoke as required by a building or life safety code and other applicable standards. Smoke dampers operate automatically on detection of smoke and must function so that smoke movement through the duct is halted.  Their activation can be by area detectors that are installed in the related smoke compartment or by detectors that are installed in the air duct systems. 

WET ALARM VALVE

WET ALARM VALVE 

WET ALARM VALVE: If we answer the question of what is a Wet Alarm Valve; Designed for applications where water is not likely to freeze. Pressurized water in the pipes is discharged to the fire area as a result of the sprinkler being activated due to the fire. While the pressurized water system is fed continuously, it also fills the delay cell at the same time. After filling the cell, the pressure switch on the cell is triggered. The pressure switch transmits alarm information to the fire alarm system or automation system. After the pressure switch is triggered, the water reaches the water motor gong and provides a mechanical alarm. This system is designed for heated volumes and needs where the water does not fall below +4 °C and does not freeze. Alarm check valve or water flow detector are used to give mechanical and electronic alarms.

WHAT IS A WET ALARM VALVE AND WHAT ARE THE GENERAL FEATURES?

Wet alarm valve is used in wet type fire extinguishing systems. It is used for applications where the water is above freezing temperature, ensuring that the pressurized water in the pipes is delivered to the fire area as a result of the sprinkler being activated in the event of a fire.

·        The water, which is pressurized in the pipes, is discharged to the fire area as a result of the sprinkler activation.

·        Pressurized water fills the delay cell at the same time as the system is fed continuously.

·        After the cell is full, the pressure switch on the cell is triggered.

·        The pressure switch transmits alarm information to the automation system.

·        Water reaches the motor gong and provides a mechanical alarm.

KEY FEATURES

Especially in wet type sprinkler systems, automatic sprinkler is fixed to pipe systems that are connected to a water source and contain water. In these systems, the sprinkler opens with the effect of the heat generated by the fire, and they allow the water to start pouring onto the burning materials. The effect of the heat from the fire activates any sprinkler connected to the system and ensures the flow of water. The released water is scattered by hitting the reflector in the sprinkler and is discharged into the fire area in the form of a smooth sprinkler. Depending on the conditions in the area of use, sprinklers are designed to activate at a specified temperature between 40°C and 350°C. Most sprinklers discharge approximately 70 to 100 liters of water per minute into the fire scene.

The wet sprinkler system can be divided into zones fed from a common column. The system zone size is determined depending on the fire hazard class of the building. In high storage areas, the maximum floor area on each floor connected to any feed column should not exceed 3716 m². If a sprinkler zone addresses multiple floors or separate occupancy zones, a traceable shut-off valve, flow switch, and test and drain valve should be installed at the entrance to the floors or zones. In the wet pipe sprinkler system, the pipes are kept constantly filled with pressurized water. It is applied only in places where there is no risk of freezing and the ambient temperature does not exceed 95 °C.

Experiences are taken into account regarding people’s safer lives in their living spaces. In this way, different standards and processes are created. The fire code standards applied in this way also include a certain system. In this system, the wet alarm valve takes on the biggest task. Due to its working principles, it ensures that the sprinkler system, which is the first responder to the fire, works effectively and smoothly. These valves, which act like a kind of heart, are responsible for activating the entire extinguishing system. Similarly, there is a dry alarm valve in check valves. However, their working principles are different. Valves used for wet areas should always have the principle of working smoothly and appropriately within the system. Wet alarm valves are used in areas where the water is not likely to freeze. It gives both mechanical (with engine gong) and electrical (pressure switches) alarms with the direction of the trim set due to the pressure difference created by the activation of the sprinklers during the fire. Can be used with delay cell to prevent false alarms.

PRODUCT INFORMATION

Wet Alarm Valve is a check valve used in wet pipe sprinkler systems to activate electrical and mechanical alarms with water flow from one or more opened sprinklers. Wet alarm valve operating principle As long as the water pressure in the sprinkler installation is equal to or more than the supply water pressure, the alarm valve is in the closed position. By opening one or more sprinklers, the wet alarm valve flap opens and water starts flowing into the system and delay chamber. When the delay chamber is completely filled with water, the pressure switch and the water alarm gong are activated by the water pressure. After the fire is brought under control, the water flow to the area can be stopped by closing the shut-off valve in the wet alarm valve station of the area where the sprinkler is opened.

In particular, one wet alarm valve should be used in each wet pipe sprinkler zone. A shut-off valve should be placed below each alarm valve. Moreover, if the sprinkler alarm valves are fed from the ring main supply line arranged inside the building, the main supply ring should be divided into zones with regional control valves. In addition, it is allowed to feed to a maximum of 4 alarm valves from each part of the ring. The diameter of the alarm valve should be selected according to the diameter of the fire zone installation column, which is determined by hydraulic calculation.

These valves, which can control both electricity and mechanics, are of vital importance in fires. In particular, the wet alarm valve in the check valves group has an important place in the sprinkler system. It is also important to adjust the water pressure as needed. The valve remains closed when the pressure is equal or greater. If one or more sprinklers are opened, the clamp of the wet alarm valve is also opened and water flow to the required cells begins. At this time, the water alarm gongs are activated by the prosostat with the water pressure created. In other words, alarm valves start to work functionally. When the fire goes out or the situation in question disappears, the shut-off valve is closed from the station and the water going to the area is stopped. This system is very useful and will allow quick intervention until the teams arrive.

What is Wet Alarm Valve and Its Uses

1.   Warehouses

2.   Workshops

3.   Hospitals

4.   Living Centers

5.   High-Rise Residences and Residences

6.   Factories

7.   Homes

8.   Hospitals

9.   Schools and universities

10.Hotel and dormitory buildings

11.Shopping malls

12.Cafeteria and restaurants

Nfpa 13 - What is the Alarm Government Valve - Wet Pipe ? 👉🏻👈🏻

Wet pipe VGAs are designed for systems with temperatures above +4°C as they are susceptible to freezing. For mechanical and electronic alarm detection, alarm check valves and flowmeter detectors are used.

VGA wet pipe normally installed in a Sprinklers system designed to distribute water in the fire in case of emergency.

VGA is designed to open automatically when a sprinkler is activated by the heat of a fire. When the valve opens, it allows water to flow into the piping system and into the Sprinklers nozzles, which then spray water into the fire.

👉🏻Application Areas:
1. Warehouses
2. Factories
3. Hospitals
4. Shopping malls
5. Skyscraper structures and residences

When the fire fighting system starts increasing pressure, water will flow into the system until reaching a balance between the water supplying with the system pressure. And the alarm check valve can put pressure on the fire pumps valve to prevent the water backflowing. Once the pressure comes to balance, the alarm check valve will be in operation state, and the middle chamber of its seat ring will be sealed. So if the alarm check valve was set at maintenance state, there will no alarm port to the alarm facility (alarm pressure switch).