Tiêu chuẩn Việt Nam TCVN 7435-1:2004 (ISO 11602-1:2000) về phòng cháy, chữa cháy - Bình chữa cháy xách tay và xe đẩy chữa cháy - Phần 1: Lựa chọn và bố trí do Bộ Khoa học và Công nghệ ban hành

NATIONAL STANDARD

TCVN 7435-1:2004 - ISO 11602-1:2000

FIRE PROTECTION – PORTABLE AND WHEELED FIRE EXTINGUISHERS - PART 1: SELECTION AND INSTALLATION

FOREWORD

The TCVN 7435-1:2004 is entirely identical to ISO 11602-1:2000

The TCVN 7435-1:2004 is compiled by the Department of Technical Standard TCVN/TC 21 on firefighting facilities, proposed by the Directorate for Standards, Metrology, and Quality, and promulgated by the Ministry of Science and Technology.

1. SCOPE

This Standard prescribes requirements pertaining to selection and installation of portable and wheeled fire extinguishers. This Standard should be used in conjunction with the TCVN 7435-2.

Portable and wheeled fire extinguishers are intended as a first line of defence against fires of limited size. They are necessary even when automatic sprinkler system, wall-mounted firefighting is installed as stand-alone measures or in combination with other firefighting facilities.

This Standard does not apply to stationary systems for extinguishing fire despite parts thereof are portable (such as nozzles, hoses attached to extinguishant delivering system).

The requirements specified in this document are minimum requirements. The use of portable and wheeled fire extinguishers at a greater quantity, at a greater capacity, or at a greater size will, in general, improve protection.

This Standard does not apply to portable and wheeled fire extinguishers aboard aircrafts, watercrafts, and road vehicles.

2. REFERENCING DOCUMENT

TCVN 7602 (ISO 7165), Firefighting – Portable extinguishers – Characteristics and design.

ISO 8421-1, Fire protection – Vocabulary – Part 1: General terms and phenomena of fire.

TCVN 7027 (ISO 11601), Wheeled fire extinguishers – Characteristics and design.

3. TERMS AND DEFINITIONS

This Standard uses terms and definitions set forth under the ISO 8421-1 and the followings:

3.1. Closed recovery system for extinguishing powder.

Means a system that allows reuse of extinguishing powders.

Note: The system allows for the recovering and transferring of powders from extinguishers to recovery containers that are closed to prevent the media from leaking into the air.

3.2. Closed recovery system for halon

Means a system that transfers halon between extinguishers and supply tanks, recovers, and refills in a manner that minimizes halon leak to the atmosphere.

3.3. Competent person

Means a person with the necessary training and experience and access to equipment, instruments, replacement parts, and information (including instruction manuals of manufacturers) and capable of inspecting and refilling in accordance with procedures detailed in this document.

Note: See Appendix A of TCVN 7435-2

3.4. Film-forming media

Means aqueous film forming foam (AFFF) and film forming fluoroprotein foam (FFFP), including types suitable with polar solvents (water-soluble flammable liquids) and types not suitable with polar solvents.

3.5. Fire extinguisher

Means portable and wheeled extinguishers.

3.6. Hazards

3.6.1. Class A hazard

Means fuel sources where Class A fires, involving materials such as wood, cloth, paper, rubber and many plastics, may be expected to develop.

3.6.2. Class B hazard

Means fuel sources where Class B fires, involving materials such as oils, greases and paints, may be expected to develop.

3.6.3. Class C hazard

Means fuel sources where Class C fires, involving materials such as natural and propane gas, may be anticipated.

3.6.4. Class D hazard

Means fuel sources where Class D fires, involving materials such as magnesium, sodium and potassium, may be anticipated.

3.7. High-pressure cylinder

Means a cylinder having a service pressure greater than 2,5 MPa at 20^oC.

3.8. Inspection

Means brief inspection which ensures that fire extinguishers are available and functional.

Note: This is intended to give reasonable assurance that the extinguisher is fully charged and operable. This is done by observing that seeing that it is in its designated place, that it has not been actuated or tampered with, and that there is no obvious damage or condition to prevent its operation.

3.9. Low-pressure cylinder

Means a cylinder having a service pressure of 2,5 Mpa or lower at 20 ^oC.

3.10. Maintenance

Means thorough examination of the extinguisher.

Note: This is intended to give maximum assurance that an extinguisher will operate effectively and safely. It includes a thorough examination and any necessary repair or replacement. It will normally reveal if hydrostatic testing is required.

3.11. Non-rechargeable extinguisher, non-refillable extinguisher

Means fire extinguisher that is not capable of (nor intended for) undergoing complete maintenance, hydrostatic testing, and being restored to its full operating capability by the standard practices used by fire equipment service companies.

3.12. Occupancy hazard (high)

Means location where the total amount of Class A combustibles and Class B flammables present, in storage, production use and/or finished product, is over and above those expected under moderate hazard occupancies.

3.13. Occupancy hazard (low)

Means location where the total amount of Class A combustible materials, including furnishings, decorations, and contents, is of minor quantity.

Note: This classification anticipates that the majority of items contained are either non-combustible or so arranged that a fire is not likely to spread rapidly. Small amounts of Class B flammables used for duplicating machines, art departments, etc., are included provided that they are kept in closed containers and safely stored.

3.14. Occupancy hazard (moderate)

Means location where the total amount of Class A combustibles and Class B flammables are present in greater amounts than expected under low hazard occupancies

3.15. Portable extinguisher

Means portable appliance containing an extinguishing medium which can be discharged and directed onto a fire by the action of internal pressure.

Note: The internal pressure may be provided by:

- a stored pressure (pressurization of the extinguishing medium container at the time of charging), or

- a gas cartridge (pressurization at the time of use through the release of gas from a separate cylinder into the medium container).

3.16. Rating

Means comparative number associated with the classification assigned to an extinguisher and indicative of its capability in the extinguishment of a standard fire.

3.17. Rechargeable extinguisher - refillable extinguisher

Means fire extinguisher capable of undergoing complete maintenance, including internal inspection of the pressure vessel, replacement of all substandard parts and seals, and hydrostatic testing.

Note: This type of extinguisher is capable of being recharged with media and propellant, and restored to its full operating capability by the standard practices used by fire equipment service companies. Rechargeable (refillable) extinguishers are marked "Recharge Immediately After Any Use" or with a similar equivalent marking.

3.18. Recharging

Means replacement of the extinguishing medium.

Note: This also includes the propellant for certain types of extinguishers.

3.19. Self-expelling medium extinguisher

Means extinguisher in which the medium has sufficient vapour pressure at normal operating temperatures to expel itself

3.20. Service, servicing

Means process which includes one or more of the following:

- Maintenance;

- Recharging;

- Hydrostatic testing

3.21. Service pressure

Means normal operating pressure at 20 ^oC as indicated on the pressure gauge or indicator and nameplate of a stored pressure extinguisher, or the pressure developed in a cartridge-operated extinguisher upon release of the gas from the cartridge into the medium container at a temperature of 20 ^oC.

3.22. Test pressure

Means pressure at which the extinguisher or its components were tested at time of manufacture.

Note: The pressure at which the shell was tested is shown on the nameplate or the extinguisher body.

3.23. Travel distance

Means distance a person must travel from any point to the closest appropriate extinguisher.

3.24. Water-type extinguisher

Means a fire extinguisher which contains a water-based medium, such as water, foam (AFFF or FFFP) and antifreeze.

3.25. Wheeled extinguisher

Means a fire extinguisher having a total mass of more than 20 kg, mounted on wheels, which is designed to be transported and operated by one person.

4. CLASSIFICATIONS, RATINGS AND PERFORMANCE OF EXTINGUISHERS

4.1. Extinguishers are classified for use on certain classes of fires and rated for relative extinguishing effectiveness by testing laboratories. This is based on the classification of fires and the fire-extinguishing potentials as determined by fire tests.

4.2. Fire classifications are as follows

- Class A: fires involving solid materials, usually of an organic nature, in which combustion normally takes place with the formation of glowing embers.

- Class B: fires involving liquids or liquefiable solids;

- Class C: fires involving combustible gases;

- Class D: fires involving combustible metals.

4.3. The classification and rating systems referenced in this document are those described in TCVN 7026:2002 and TCVN 7027:2002.

4.4. Extinguishers shall be in accordance with TCVN 7026:2002 and TCVN 7027:2002.

4.5. The identification of the certification organization, the fire-extinguishing classification and rating and the performance standard that the extinguisher meets are clearly marked on each extinguisher.

5. GENERAL REQUIREMENTS

5.1. Extinguishers shall be maintained in a fully charged and operable condition, and shall be kept in their designated places at all times when they are not being used.

5.2. Extinguishers shall be conspicuously located where they will be readily accessible and immediately available in the event of fire. Preferably they shall be located along normal paths of travel, including exits from areas.

5.3. Cabinets housing extinguishers shall not be locked.

Note: Where extinguishers are subject to vandalism, locked cabinets may be used provided they include means of emergency access.

5.4. Extinguishers shall not be obstructed or obscured from view.

Note: In large rooms and in certain locations where visual obstruction cannot be completely avoided, means shall be provided to indicate the location of the extinguishers.

5.5. Extinguishers shall be installed on hangers or in brackets, or mounted in cabinets, unless the extinguishers are of the wheeled type.

5.6. Extinguishers installed under conditions where they are subject to dislodgement shall be installed in specifically designed brackets.

5.7. Extinguishers installed under conditions where they may be subject to physical damage shall be protected from impact.

5.8. Extinguishers having a gross mass of 18 kg or less shall be installed so that the top of the extinguisher is not more than 1,5 m above the floor. Extinguishers having a gross mass greater than 18 kg (except wheeled types) shall be installed so that the top of the extinguisher is not more than 1,0 m above the floor. The clearance between the bottom of extinguishers mounted on hangers or brackets and the floor shall not be less than 3 cm.

5.9. When mounted or placed in their intended location, the operating instructions shall face outwards or towards the most likely direction of access.

5.10. Where extinguishers are installed in closed cabinets that are located outdoors, or are exposed to elevated temperatures, such cabinets shall be provided with ventilation openings.

5.11. Extinguishers shall not be installed in areas where temperatures are outside the range marked on the extinguisher, or where they may be exposed to elevated temperatures from heating sources.

5.12. Units of measurement in this document are in accordance with the International System of Units (SI). Some units (e.g. cm, bar and litre), outside of but recognized by SI, may appear as they are commonly used in international fire protection. See ISO 1000.

6. SELECTION OF EXTINGUISHERS

6.1. General provisions

The selection of extinguishers for a given situation shall be determined by the character and extent of the fires anticipated, the construction and occupancy of the individual property, the hazard to be protected against, the ambient temperature conditions, and other factors. The number, rating, placement and limitations of use of the required extinguishers shall meet the requirements of Article 7.

6.2. Halon fire extinguishers

The use of halon fire extinguishers shall be limited to applications where a clean medium is necessary to extinguish fire efficiently without damaging the equipment or area being protected, or where the use of alternative media could cause a hazard to personnel in the area.

6.3. Selection by hazard

6.3.1. Extinguishers shall be selected for the specific class(es) of hazards to be protected against.

6.3.2. Extinguishers for protection against Class A hazards shall be selected from extinguishers with the appropriate Class A rating.

Note: For halon-type extinguishers, see 6.2.

6.3.3. Extinguishers for protection against Class B hazards shall be selected from extinguishers with the appropriate Class B rating.

Note: For halon-type extinguishers, see 6.2.

6.3.4. Extinguishers for protection against Class C hazards shall be of the powder type.

6.3.5. Extinguishers and extinguishing media for protection against Class D hazards shall be of types suitable for use on the specific combustible-metal hazards.

6.3.6. Extinguishers for protection against hazards which involve energized electrical equipment shall be of the carbon dioxide, powder, halon, or water-based types which have been tested and found suitable for this application. Note: For halon-type extinguishers, see 6.2.

Carbon dioxide extinguishers equipped with metal horns are not considered safe for use on fires involving energized electrical equipment.

While powder extinguishers may be effective in extinguishing fires in delicate electronic equipment, the residue from their media may seriously damage the equipment they are intended to protect.

6.4. Selection for pressurized flammable liquid and gas fires

6.4.1. Extinguishers containing media other than powder are relatively ineffective on pressurized flammable liquids and pressurized gas fires. The selection of extinguishers for this type of hazard shall be made on the basis of recommendations by the manufacturers of this specialized equipment. The system used to rate the effectiveness of extinguishers on Class B fires (flammable liquids in depth) is not applicable to these types of hazard. It has been determined that special nozzle design and rates of media application are required to cope with such hazards.

Warning: It is undesirable to attempt to extinguish this type of fire unless there is reasonable assurance that the source of fuel can be promptly shut off.

6.4.2. Extinguishers for three-dimensional Class B hazards involving Class B materials in motion, such as pouring, running or dripping flammable liquids, shall be selected on the basis of recommendations by the manufacturers of the extinguishers. The system used to rate extinguishers on Class B fires (flammable liquids in depth) is not directly applicable to this type of hazard.

Note: The installation of fixed systems for such hazards should be considered when applicable.

6.4.3. Extinguishers for use on water-soluble flammable liquid fires, such as alcohols, esters, ketones, etc., shall not be of the AFFF or FFFP type unless the extinguishing medium has been specifically tested and found to be suitable for such applications.

6.4.4. Wheeled extinguishers shall be considered for hazard protection in high hazard areas or where

- High media flow rates are required;

- Increased media stream range is required;

- Increased media capacity is required.

7. DISTRIBUTION OF EXTINGUISHERS

7.1 General requirements

7.1.1. The minimum number of extinguishers needed to protect a hazard shall be determined as outlined in this Article.

Additional extinguishers may be installed to provide more suitable protection for special hazards. Consideration shall be given to the protection of high storage items and other hazards requiring extinguishers with a suitable vertical range. Extinguishers having ratings less than specified in Tables 1 and 2 may be installed, provided they are not used to fulfill the minimum protective requirements of this Article.

7.1.2. Extinguishers shall be provided for the protection of both the building structure, if combustible, and the hazards contained therein.

7.1.3. Required building protection shall be provided by extinguishers suitable for Class A fires.

7.1.4. Protection of building contents shall be provided by extinguishers suitable for such Class A, B, C or D fire hazards as may be present.

7.1.5. Extinguishers provided for building protection may be considered also for the protection of occupancies having a Class A fire potential.

7.1.6. Buildings having Class B and/or Class C hazards shall have a standard complement of Class A extinguishers for building protection, plus additional Class B and/or Class C extinguishers. Where extinguishers have more than one letter classification, they may be considered to satisfy the requirements of each letter class.

7.1.7. Occupancies shall be classified generally as low hazard, moderate hazard, or high hazard occupancies (see 3.12 to 3.14). Limited areas with greater or lesser hazards shall be protected as required. Consideration shall also be given to the number of occupants, their ages, and their ability to evacuate in the case of fire.

7.1.8. On each floor level, the area protected and the travel distances are based on extinguishers installed in accordance with Tables 1 and 2.

7.2. Fire extinguisher ratings and placement for Class A hazards

7.2.1. Fire extinguishers for the different types of hazards shall be provided on the basis of Table 1.

Table 1

7.2.2. At least two extinguishers as recommended in Table 1 shall be provided per storey (floor).

Note: For storeys having an area of less than 100 m², one extinguisher may be provided.

7.2.3. The protection requirements may be fulfilled with extinguishers of higher ratings, provided the travel distance to such larger extinguishers does not exceed the distance shown in Table 1.

7.3. Extinguisher rating and placement for Class B hazards other than hazards in flammable liquids of appreciable depth (in excess of 0,6 cm) and for Class C hazards.

7.3.1. Extinguishers for the listed types of hazard shall be provided on the basis of Table 2.

Note: Extinguishers of lesser rating, for small specific hazards within the general hazard area, may be used, but shall not be considered as fulfilling any part of the requirements of Table 2.

Table 2

For pressurized flammable liquid and gas fires, see 6.4.

For fires involving water-soluble flammable liquids, see 6.4.3.

7.3.2. Two or more extinguishers of lower rating shall not be used to fulfill the protection requirements of Table 2.

Note: Up to three AFFF- or FFFP-type extinguishers, provided the sum of their ratings equals or exceeds the minimum required rating, may be used to fulfill the requirements of a single extinguisher of the required rating.

7.3.3. The protection requirements may be fulfilled with extinguishers of higher ratings, provided the travel distance to such larger extinguishers does not exceed the distance shown in Table 2.

7.3.4. At least two extinguishers as recommended in Table 2 shall be provided per storey (floor).

Note: For storeys having an area of less than 100 m², one extinguisher may be provided.

7.4. Extinguisher size and placement for Class B hazards in flammable liquids of appreciable depth (in excess of 0,6 cm)

7.4.1. Extinguishers shall not be installed as the sole protection for flammable liquid hazards of appreciable depth (greater than 0,6 cm) where the surface area exceeds 1 m².

 7.4.2. For flammable liquid hazards of appreciable depth, such as in dip or quench tanks, a Class B extinguisher shall be provided on the basis of at least 144 numerical units of Class B extinguishing potential per square meter of the estimated maximum fire area.

Note 1: Where approved automatic fire protection devices or systems have been installed for a flammable liquid hazard, additional portable Class B fire extinguishers may be waived. Where so waived, Class B extinguishers shall be provided as covered in 7.3.1 to protect areas in the vicinity of such protected hazards.

Note 2: AFFF- or FFFP-type extinguishers may be provided on the basis of 89B of protection per square meter of hazard.

7.4.3. Two or more extinguishers of lower ratings shall not be used in lieu of the extinguisher required for the largest tank.

Note: Up to three AFFF- or FFFP-type extinguishers may be used to fulfill the requirements of a single extinguisher of the required rating, provided the sum of their ratings equals or exceeds the minimum required rating.

7.4.4. When the size of a Class B hazard of appreciable depth is such that it cannot be protected by portable extinguishers, the use of a wheeled extinguisher may be considered when it can be demonstrated that it is capable of protecting against the hazard. Where so used, Class B portable extinguishers shall also be provided, as covered in 7.3.1, to protect areas in the vicinity of such a hazard.

7.4.5. Travel distances to extinguishers shall not exceed 15 m.

7.4.6. Scattered or widely separated hazards shall be individually protected. An extinguisher in the proximity of a hazard shall be carefully located to be accessible in the presence of a fire without undue danger to the operator.

7.5. Extinguisher size and placement for electrical hazards

7.5.1. Electrical hazards include hazards either directly involving or surrounding electrical equipment.

7.5.2. As the hazard itself is a Class A or Class B hazard, the extinguishers shall be sized and located on the basis of the anticipated Class A or B hazard.

7.5.3. Where energized electrical equipment may be encountered, the extinguishers shall have been proved to be suitable for use on energized electrical equipment and so marked.

Electrical equipment should be de-energized as soon as possible to prevent re-ignition.

7.6. Extinguisher size and placement for Class D hazards

7.6.1. Class D extinguishers shall be provided for hazards involving combustible metals.

7.6.2. The travel distances to extinguishers for Class D hazards shall not exceed 20 m.

7.6.3. The size and number of extinguishers shall be determined on the basis of the specific combustible metal, its physical particle size, and the area to be covered.