NOTE ON INTERNAL FIRE HYDRANT SYSTEM

 

NOTE ON INTERNAL FIRE HYDRANT SYSTEM

Internal fire hydrants are provided for use by the fire brigade or other internally trained fire personnel. These Internal fire hydrants provide means of delivering considerable quantities of water to extinguish the fire or to prevent the spread of fire. These internal fire hydrant system effectiveness in stopping the fire is more pronounced if the premises are provided with an early warning device of any outbreak of fire.

Internal hydrant installation comprises of the following elements:

1.        STATIC TANK OR TERRACE TANK

2.       RISER SYSTEMS

3.       FIRE FIGHTING PUMP/PUMPS

4.       COMPONENTS/ ACCESSORIES:

1) STATIC TANK / TERRACE TANK:  Static / terrace tank is meant to store adequate quantities of water for firefighting purposes.  Static tanks are placed underground or on the leveled surface.  Terrace tanks are placed on the top especially for multi-story buildings. Underground tanks (static tanks) are to be provided with compartments with external interconnection at bottom levels having gate valves at both ends. These gate valves will help in periodical maintenance/cleaning purposes. The most important thing is to provide at least two-man holes on the tank to facilitate fire appliances to draw water as and when necessary. The access roads to these tanks should be 6m in width with no encroachment and obstructions so that fire brigade trucks can easily maneuver. If tanks are built on the terrace, they should be properly placed on suitable girders and plates for equal distribution of load.

The capacity of the tank is decided by the area and the number of risers.

2)RISER SYSTEMS: They are four types of riser systems

1.      Dry riser

2.     Wet riser

3.      Wet riser cum down riser

4.     Down comer system

 Dry riser: This is a kind of arrangement within the building above 15 m height but not exceeding 24 m using vertical rising mains not less than 100 mm internal diameter and comprising of landing valves on each floor/landing. The vertical mains pipelines are normally dry. The rising main should have a two-way fire service inlet without a non-return valve at ground level about 1 meter from the ground level in front of the building. These fire service inlet valves should have no obstruction.  The vertical mains are provided with an air-releasing valve at the top level and a drain valve at the bottom.  In the event of a fire incident, water is pumped into the riser from Fire tenders using these inlets.

Wet riser:  This is a kind of arrangement in which rising mains are permanently charged with water which is under pressure and connected to dedicated fire pumps and also provided fire service inlets. This wet-riser installation in the building should be so situated as not to be farther than 30 m from any point in the area covered by the hydrant

Wet riser CUM downcomer:  This uses a combination of both WET RISER and DOWN COMER system using terrace tanks and static tank

Down Comer System:  This is a kind of arrangement in which down comer mains are connected to terrace tanks charged with water through the terrace pump, gate valve, and a non-return valve and landing valves on each floor.  There is also provision given for inlet connections at ground level so that water can be charged

3)FIRE FIGHTING PUMP/PUMPS: Firefighting pump/pumps with all fitments and components and pump control panel, housed in a pump house should be of adequate dimensions, there are four types of pumps that are used

· Fire pump: This is the main pump connected to the static tank and help in supplying water to the wet risers.

· Stand by pump: This pump is used as an alternative to the main Fire pump

·  Terrace pump: This is connected to the Terrace tank

· Jockey pump: This pump is to regulate the pressure in the hydrant lines, in case if there is a drop in pressure, this automatically starts and stops when required pressure is reached in pipelines

Depending upon the suction and delivery pipe sizes the capacity of pumps should be 450 l/min to 1400 l/min for Terrace pumps and 2280 l/min to 4540 l/min for fire pumps stationed in the firehouse.

For a wet-riser system, two automatic pumps should be installed.

· One acts as a duty pump it will operate automatically when the drop in pressure in the pipeline happens due to the hydrant/hose reel getting up opened

· The second one acts as a standby pump which automatically starts up in case of failure of the duty pump. The interlocking mechanism between the pumps will make sure that only one pump will run

It is preferable to have positive suction to have a permanently flooded suction, if not possible a priming tank with foot valve and Stainer to be provided, this helps in keeping the suction permanently flooded.

4)COMPONENTS/ACCESSORIES: All necessary components like a hose reels, hose cabinets, fire hoses, nozzles and branch pipes should be properly maintained also spare hose pipes, landing valve lugs, valves wheel etc should be also be properly secured and kept in hose cabinet (painted red with a glass front)

INTERNAL FIRE HYDRANT SYSTEM MAINTENANCE

·   Periodic inspections near all the places and approach ways to hydrants should be done to ensure that there are no obstructions that are preventing proper accessibility and that hydrant indicator plates are in position.

 

    For every 6 months hydrant components like Inlets, landing valves, drain valves, door hinges, and landing valve boxes should be inspected every six months.

Valves, spindles, glands, and washers also to be ensured that they are checked every 6 months for any leakages and to ensure that they are in satisfactory condition so that all equipment is ready for immediate use.

·       Water storage tanks cleanliness is also important and to be ensured.

• Proper maintenance of pumps, when any part like the outlet  on the rising mains is found to be defective and no replacement is immediately available, the whole valve assembly should be removed from the main and should be replaced with a blanking off plate or plug, so that the system remains operative without disturbing the whole system

·       Regular inspection should be done to Hose reels to ensure that there are no leaks in

o   Inlet valve

o   Automatic on/off valve

o   Glands

o   Tubing

o   Shut off nozzle

and also, to ensure that the outlet of the nozzle is not chocked.

 

                                                                                                                                                            FIRE Notes by PJ Mohan

                                                                                                                                                                            Sr. Faculty, NIFS

 

A NOTE ON FIRE DETECTORS

 

A NOTE ON FIRE DETECTORS

 Fire detectors are meant to detect any one of the below characteristics of a fire

·        Heat

·        Smoke

·        Radiation (given by flame)

 There are different detectors available to choose from, but we cannot conclude that a particular detector is suitable for all applications.  Every detector whether it designed to detect either heat, flame or smoke or sometimes a combination, each one of them has their advantages and disadvantages, and no one type of detector is most suitable for all applications, the choice of a detector depends primarily on

      THE SPEED OF RESPONSE: The faster a detector detects the particular characteristic of fire (smoke, heat or flame) the faster would be the response to extinguish the fire.

       FALSE ALARMS: The false alarms can be an outcome of malicious, mistaken or accidental intention, too much detector sensitivity can also increase false alarms, smoke detectors are faster than heat detectors but may give more false alarms than heat detectors.

3.    NATURE OF FIRE HAZARD: It is important to understand the nature of the fire hazard that exists before selecting the required fire detector.  Some fires give more smoke and some intense heat.  The selection should be based on the requirement

4.    COST:  Using several types of detectors and reducing the space between detectors may help in a better system, but that would increase the cost which may not be feasible for some industries.

5.  SUITABILITY OF THE ENVIRONMENT: Dusty environments will provide false alarms if smoke detectors are used, near heat generation, equipment certain type of heat detectors may give false alarms, the suitability of the environment also plays a vital role

TYPES OF FIRE DETECTORS

Fire detectors can be classified into

·        HEAT DETECTORS

·        SMOKE DETECTORS

·        FLAME DETECTORS

·        SPARK/EMBER DETECTORS

HEAT DETECTORS: These detectors work on the principle of heat detection in the fire. These heat-sensitive fire detectors sense heat due to the temperature rise with the help of probes/sensors which detect heat during the early stages of fire.

Typical examples are bimetallic type, fusible alloy type, pneumatic type, etc.Heat sensitive detectors (both resettable and non-resettable) are of the following types

1.      FIXED TEMPERATURE TYPE HEAT DETECTOR

2.      RATE OF RISING – CUM FIXED TEMPERATURE HEAT DETECTOR

3.      PROBE TYPE HIGH-TEMPERATURE BI-METAL HEAT DETECTOR

4.      LINEAR HEAT SENSING CABLE TYPE HEAT DETECTOR

1)FIXED TEMPERATURE DETECTOR:  These detectors designed to operate at a fixed predetermined value, when the temperature of the detector exceeds the set predetermined value then immediately the probe senses it and gets activated.

2)RATE OF RISING – CUM FIXED TEMPERATURE HEAT DETECTOR: These detectors are designed to operate based on the rate of rising in temperature based on time.

3)PROBE TYPE HIGH-TEMPERATURE BI-METAL HEAT DETECTOR: In places like oven and furnace areas where electronic sensors cannot be used and where the temperature is above 80⁰C these bimetallic heat detectors are highly suitable

4)LINEAR HEAT SENSING CABLE TYPE HEAT DETECTOR: In the case of a Digital sensor, the heat-sensitive insulator separates the two core cables consist of two core cable in which the conductors are separated by a heat-sensitive insulator. When a specified temperature is reached, the cable insulation breaks down and an alarm is indicated

SMOKE DETECTORS: These detectors work on the principle of Invisible aerosols and smoke that gets released in certain cases during the early stage of fire. There are three types of smoke detectors like

1.      IONIZATION SMOKE DETECTOR

2.      OPTICAL (PHOTOELECTRIC) SMOKE DETECTOR

3.      AIR SAMPLING TYPE SMOKE DETECTOR

1)IONIZATION TYPE SMOKE DETECTOR:  These detectors are designed to sense aerosols given off by fires with the help of Ionizing chambers fixed within the smoke detectors.

2)OPTICAL (PHOTOELECTRIC) SMOKE DETECTOR: These detectors are designed to operate when the light gets attenuated or scattered by the presence of smoke particles. This attenuation or scattering of light alters the standard condition and alarm is raised 

3)AIR SAMPLING TYPE SMOKE DETECTOR:  These types of detectors are based on a system of piping or tubing distribution network that runs from the detector to the areas to be protected. An aspiration fan in the detector housing draws air from the protected area back to the detector through air sampling ports, piping or tubing. At the detector, the air is analyzed for fire products.

FLAME DETECTORS: These detectors work on the principle of sensing the emitted radiant energy released from the fire combustion process at specific wavelength bands determined by the combustion chemistry of the fuel. There are classified into

1.      UV FLAME DETECTOR

2.      IR FLAME DETECTOR

3.      IR/UV FLAME DETECTOR

1)UV FLAME DETECTOR:  These detectors use ultraviolet-sensitive photocathode for detecting flame. It has a narrow spectral sensitivity of 185 to 260 nm which is insensitive to visible light.

2)IR FLAME DETECTOR: These detectors are designed to operate in the INFRARED spectrum of light. They sense wavelength in the infrared spectrum

3) IR/UV FLAME DETECTOR: These detectors are designed to operate at both UV AND INFRARED spectrum

EMBER /SPARK DETECTORS: Spark/ember detectors are installed primarily to detect sparks and embers that could if allowed to continue to bum, precipitate a much larger fire or explosion These detectors sense radiant energy from sparks or embers, or both. These devices are normally intended to operate in dark environments and the infra-red part of the spectrum.

These SPARK/EMBER detectors use phototransistors or photodiodes to sense the radiant energy from sparks or embers. These detectors are extremely sensitive (microwatts) and their response times can be made very short (microseconds). Spark/ember detectors are installed primarily to detect sparks and embers that could if allowed to continue to bum, precipitate a much larger fire or explosion.

CONCLUSION:  Each type of detector is designed to detect a particular type of fire. Hence in any building, careful planning for a combination of various detectors is necessary depending upon the type of fire hazard and nature of fire that can exist at that point. The fire behavior of the contents of each part of the building and the design of the building should be considered during planning for installing the detectors. The susceptibility of the contents to heat, smoke, and water damage shall also be considered. Hence any type of detectors / or combination of detectors chosen shall be based on the conditions that provide the earliest reliable warning.

                                                                                                                                                             FIRE Notes by PJ Mohan

                                                                                                                                                                            Sr. Faculty, NIFS

 

HAZARDOUS ENERGY AND LOTO

 

WHAT IS HAZARDOUS ENERGY 

Hazardous energy is any energy source either in primary form or residual form that has the potential to cause injury or death to workers while undertaking servicing or maintenance activities on machines or equipment due to unexpected energization or accidental release of stored energy. 

The different types of hazardous energies are 

1.     Electrical Energy

2.     Chemical Energy

3.     Radiation Energy

4.     Thermal Energy

5.     Kinetic Energy

6.     Potential Energy

 

ELECTRICAL ENERGY: Electrical energy is the commonest energy hazard encountered in industries, it is dangerous because it can cause shock, burns, secondary injuries, arc blast exposures. Source of energy is either live through conductors or stored as capacitors, either in the form of low voltage or high voltage.  These electrical hazards can be hazardous or injurious to health

CHEMICAL ENERGY: Energy associated with hazardous chemical reactions. Explosions, fires and heat of reaction caused by hazardous chemical reactions result in the release of large amounts of energy in the form of heat and pressure. All types of chemicals whether they are flammable, combustible or corrosive release hazardous chemical energies. All chemicals stored near a potential ignition source can cause explosions are fires.

RADIATION ENERGY:  Electromagnetic sources like X rays, UV rays, IR rays have radiation energy, Exposure to alpha, beta and gamma rays are harmful to human health and can cause burns and radiation sickness 

THERMAL ENERGY: This energy is also encountered frequently in industries during servicing or maintenance operations, Thermal energy which involves both cold and hot systems is about the motion of particles at the particulate level. Instances of fire and release of gases during welding, torch work, cryogenic systems, working near boiler which involves steam to dissipate hazardous thermal energy in the form of heat. The most common injuries are burns, frostbite and dehydration. Service personnel working on steam pipes can encounter these situations

KINETIC ENERGY: This is the energy of machinery, equipment or material in motion. Moving, spinning or rotating equipment parts continuing their motion even after power is switched off are the examples of kinetic energy 

POTENTIAL ENERGY: 

o   Energy stored in coiled materials like springs which get released when expands suspended or elevated objects or materials

o   Energy stored within pressurized liquids used to lift objects or equipment 

  

CONTROL OF HAZARDOUS ENERGY THROUGH

LOTO (LOCKOUT / TAGOUT)

 

Since hazardous energy can cause injuries or fatalities if not properly disconnected or isolated from the required workplace, there should be a system that should be in place for controlling the hazardous energy during servicing or maintenance operations, one such procedural system is LOTO procedure. LOTO is LOCKOUT / TAGOUT, it is a safety procedure that assists in the protection of employees who are working near equipment and machinery for servicing/maintenance by locking out/tagging out to ensure that all possible and potential sources of hazardous energies have been isolated. Normal production operations do not require isolation as this work is a repetitive, routine and integral to the normal use of equipment or machinery 

The following steps are to be followed for every de-energization and lockout process.

1. IDENTIFICATION AND NOTIFICATION: The Machinery or equipment to be identified for LOCKOUT on which service or maintenance is planned. All employees who work near the machine or who operate any part of the machine or any part of the equipment should be notified that LOTO will be performed on their equipment. This LOTO will be an integral part of the WORK PERMIT SYSTEM if work permit system is taken.

2.     SHUTDOWN OF MACHINE: The identified machinery to be Shut off completely by ensuring that all the moving or rotating parts come to a complete halt. The machine or equipment must be shut down in a STEP-BY-STEP procedure to avoid the generation of new hazard(s) to employees or damage to the machine or equipment as a result of the de-energization.

3.     ISOLATION OF MACHINE OR EQUIPMENT: Identifying and de-energizing all primary and residual hazardous energy sources so that the machine or equipment comes to a complete zero energy state.  Isolating devices are needed to control the energy to the machine or equipment. These energy isolating devices must be located and operated in such a manner as to isolate the machine or equipment from all the energy source(s). that are needed to control the energy to the machine or equipment.

4.   APPLICATION OF LOCKS: Across each identified hazardous energy sources, there should be a personal lock applied at all energy isolating devices along with the tag.  Employees who are performing the lockout / Tagout must attach a lockout/ Tagout device to each energy-isolating device and ensure that they will hold the energy isolating devices in a safe or off position.

5.     VERIFICATION OF DE-ENERGIZATION:  Before carrying out the service/maintenance work, the de-energization and lockout process to be verified for its effectiveness by testing after each energy-isolating device is locked out or after a group of nearby devices is locked out. For example, checking the valve position, checking with the help of instruments to see if any supply still exits like pressure gauges, to check the electrical points and circuit elements for any induced voltages and all the keys to open the locks are kept in LOTO BOX which is also LOCKED and kept with the person who undertakes the service/maintenance work.

6.    RELEASE FROM LOCKOUT / TAGOUT AFTER THE WORK IS COMPLETED: Once the work has been completed and the unit is to be placed in service the following steps to be performed for release from Lockout / Tagout

·       Work area to be inspected and ensured that all tools and employees have been removed and machine or equipment components are operationally ready. All affected employees to be notified that Lockout / Tagout devices are being removed.

·       Lockout / Tagout Devices to be removed by the authorized personnel in their respective departments along after getting a confirmation by the service/maintenance personnel and physically inspecting the work area. All energy isolating devices are kept back to the normal positions 

·       After Lockout / Tagout devices have been removed all affected employees to be notified that the machine or equipment can be taken up for and before a machine or equipment is started, affected employees shall be notified that the Lockout / Tagout device(s) have been removed.

HSE Notes by PJ Mohan

Sr.Faculty, NIFS 

 

IMPORTANCE OF SAFETY COMMITTEE

                                               

THE IMPORTANCE OF SAFETY COMMITTEE

WHAT IS SAFETY COMMITTEE?

It is a method of involving all levels of employees in an organization to understand the organizations' safety and health objectives along with the diversity and variability of workplace hazards that can impact any employee while discharging their duties and accordingly taking the required measures based on an agreed and accepted terms with clearly defined responsibility and action plans along with continuous monitoring of implemented controls (or) arrangements for their effectiveness.

It is a discussion platform on safety and health matters and possible solutions where the participation, involvement, co-operation and commitment of employees is ensured so that everyone has the shared responsibility towards ensuring safety and health at work of the employees.

PURPOSE OF SAFETY COMMITTEE

The main purpose of any safety committee is to 

·       Promote encouragement and participation of employees in expressing their safety and health issues/concerns at workplaces with regards to unsafe acts or unsafe conditions

·       To promote co-operation between the employer and employees for carrying out action plans to ensure the safety and health at work of the employees.

·       To help reduce the risk of workplace injuries and illnesses.

 

STRUCTURE OF SAFETY COMMITTEE

The structure of the safety committee should be formed based on the consultation between the top management and the workers so that a proper representation of interests of management and employees are taken care of.  The main roles are

1)Chairman who governs and oversees the proper functioning of the safety committee, his role is very important since he represents the managements real and practical interest in accident prevention and providing a safe workplace. 

2)Safety officer/Secretary:  The safety advisor is responsible for the agenda of the meeting and makes sure all the persons responsible to close the open safety points prepare a proper report and present to the committee and plays a vital role in organizing and functioning of safety committee. 

3) Committee members:  These are the persons who are selected from different departments/functions at all levels 

 

RESPONSIBILITIES AND DUTIES OF SAFETY COMMITTEE

1.   To select members from different areas and levels of the organization covering all departments and functions and clearly defining the rules and responsibilities of all the participants, this helps the industry to cover the overall safety requirements.

2.   Holding regular meetings, for this, the meeting schedules should be planned for the entire year so that all committee members will be prepared.  Example on biweekly/monthly basis/quarterly basis etc. 

3.   The minutes of the meeting to be recorded in writing and shall be produced to the inspector on demand and a copy shall be sent to the factories inspector of the region concerned

4.   The minutes of the meeting (recording and disseminating), which should consist of 

·       Previous or pending safety problems/ Issues discussed and action plan regarding the same.

·       New safety problems discussed and actions proposed to correct the same with responsibility assigned with time.

·       New methods discussed to increase safety awareness among the employees.

·       The achievements of the safety committee.

·       The persons who are present/absent for the committee.

·       The approvals required from top management etc.

 

  

FUNCTIONS OF SAFETY COMMITTEE

The main functions of any safety committee are 

ANALYZE:  The safety committee shall analyse all the accident/incident/Near miss reports and discuss among the members who are from different levels and departments to understand the root causes and to reach a better solution/control and ensure proper responsibility to implement the solutions with an accepted time frame.

MONITOR: The safety deviations/observations pointed out in reports (which include internal safety audits, external safety audits, safety inspection report, safety and occupational health surveys, risk assessment, emergency and disaster management plans and all safety observations data collected from various sources) should be keenly monitored for all the implementation of recommendations in the reports and to observe closely for any repetitive safety issues and the same should be discussed during the committee meeting.

REVIEW: The committee should keep track of all safety goals and their progress across all parameters that are defined and accordingly review them. A proper review should be conducted for all the safety and health policies and procedures established by the organization

TRAINING NEEDS: The effectiveness of training programmes that are given to all the employees should be verified and the training programmes needs also to be discussed in the committee meetings to understand the specific needs of all employees for making sure that companies Occupational health and safety management system goals, objectives, and safety training activities are accomplished by the safety committee

PARTICIPATION: The committee should ensure measures to stimulate interest in employers and workers in safety by organising safety competitions, talks and other activities on safety. There needs to be an equal number of representatives of workers and management, the workers’ representatives of this committee shall be elected by the workers. 

STATUTORY REQUIREMENT OF SAFETY COMMITTEE

    The importance of safety committee can be understood by the fact that its mention in statutory requirements like

ACT /RULE/REGULATION	REQUIREMENT
1) Section 41- G in The Factories Act, 1948	The occupier shall, in every factory where a hazardous process takes place, or where hazardous substances are used or handled, set up a Safety Committee consisting of an equal number of representatives of workers and management to promote co-operation between the workers and the management in maintaining proper safety and health at work and to review periodically the measures taken in that behalf
2)  The Dock Workers (Safety, Health & Welfare) Regulations, 1990	At every port, there shall be constituted a safety committee which shall be headed by an officer, not below the rank of Deputy Chairman of the Port.
3)The mines act 1955	the formation of safety committees in every mine where more than 100 persons are employed
4) The Building & Other Construction Workers (Regulations of Employment and Conditions of Service) Act, 1996	In every establishment wherein five hundred or more building workers are ordinarily employed, the employer shall constitute a Safety Committee consisting of a such number of representatives of the employer and the building workers as may be prescribed by the State Government: Provided that the number of persons representing the workers, shall, in no case, be less than the persons representing the employer.

 

 

HSE Notes by PJ Mohan

Sr.Faculty, NIFS