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1、BRITISH STANDARD BS 6896:1991 Specification for Installation of gas-fired overhead radiant heaters for industrial and commercial heating (2nd and 3rd family gases) Licensed Copy: London South Bank University, London South Bank University, Thu Dec 07 06:40:33 GMT+00:00 2006, Uncontrolled Copy, (c) BS
2、I BS 6896:1991 This British Standard, having been prepared under the direction of the Gas Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 28 June 1991 BSI 02-1999 First published August 1987 Second edition June 1991 The following BSI refe
3、rences relate to the work on this standard: Committee reference GSE/30 Draft for comment 89/71641 DC ISBN 0 580 19044 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Gas Standards Policy Committee (GSE/-) to Technical Committee GSE/30,
4、 upon which the following bodies were represented: British Flue and Chimney Manufacturers Association British Gas plc Confederation for the Registration of Gas Installers Consumer Policy Committee of BSI Department of the Environment Department of Trade and Industry (Consumer Safety Unit, C A Divisi
5、on) Health and Safety Executive Institute of Domestic Heating and Environmental Engineers Institution of Gas Engineers Liquefied Petroleum Gas Industry Technical Association (UK) Society of British Gas Industries Trades Union Congress The following bodies were also represented in the drafting of the
6、 standard, through subcommittees and panels: British Combustion Equipment Manufacturers Association Coopted member Loss Prevention Council Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Thu Dec 07 06:40:33 GMT+00:00
7、 2006, Uncontrolled Copy, (c) BSI BS 6896:1991 BSI 02-1999i Contents Page Committees responsibleInside front cover Forewordii Section 1. General 1Scope1 2Definitions1 Section 2. Installation 3Heat input requirements for full space heating2 4Materials and components2 5Appliances2 6Siting2 7Air supply
8、3 8Building ventilation5 9Gas supplies and pipework5 10Electrical controls and connections6 11Other controls6 12Flues6 Section 3. Inspection and commissioning 13Inspection8 14Commissioning8 15Instructions8 16Servicing8 Appendix A Exchange of information9 Appendix B Checks to be carried out prior to
9、commissioning9 Appendix C Testing for carbon dioxide in the environment9 Table 1 Ventilation openings4 Table 2 Ventilation openings/flow rate5 Publication(s) referred to10 Licensed Copy: London South Bank University, London South Bank University, Thu Dec 07 06:40:33 GMT+00:00 2006, Uncontrolled Copy
10、, (c) BSI BS 6896:1991 ii BSI 02-1999 Foreword This British Standard has been prepared under the direction of the Gas Standards Policy Committee. It is a revision of BS 6896:1987 which is superseded and withdrawn. This edition introduces technical changes to bring the standard up to date but it does
11、 not reflect a full review of the standard, which will be undertaken in due course. Attention is drawn particularly to technical changes to clauses 2, 6, 7, 9, 12 and 16. NOTEThis standard has been prepared in the format of a practice specification as defined in PD 6501-1. This allows the requiremen
12、ts of the specification to be supported by recommendations. To comply with this specification, the user has to comply with all its requirements. He may depart from recommendations, but this would be his own responsibility and he would be expected to have good reasons for doing so. A British Standard
13、 does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. In particular, attention is drawn to: a) Statutory Instrume
14、nt 1358:1984 (as amended). The Gas Safety (Installation and Use) Regulations 1984 b) Statutory Instrument 1065:1985 (as amended). The Building Regulations 1985 c) Statutory Instrument 1596:1981 (as amended). The Building Standards (Scotland) Regulations 1981 d) The Health and Safety at Work etc. Act
15、 1974 e) The Electricity at Work Regulations 1989 Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This wi
16、ll be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Thu Dec 07 06:40:33 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6896:1991 BSI 02-19991 Section 1. General 1 Scope This British Standard specifies requirement
17、s for the installation, inspection and commissioning of gas-fired overhead radiant heaters for the environmental heating of premises other than domestic dwellings. It applies to installations supplied with 2nd and 3rd family gases including mixtures of liquefied petroleum gas (LPG) and air. Appendix
18、 A highlights points on which design/installation collaboration is essential. NOTE 1This standard does not apply to: a) heaters supplied with a heated fluid from a separate source; b) heaters supplied for process applications; c) portable or transportable heaters. NOTE 2The titles of the publication
19、s referred to in this standard are listed on page 10. 2 Definitions For the purposes of this British Standard, the definitions given in BS 1179:1967 and in BS 1179-6:1980 apply, together with the following. 2.1 hazardous area a space in which explosive gas-air mixtures are or may be expected to be p
20、resent in quantities such as to require special precautions for the construction, installation and use of electrical apparatus and fuel-fired appliances NOTESee BS 5345-2 and BS 6467-2. 2.2 high-level ventilation ventilation above the level of the heater (See also 7.3.3.) 2.3 low-level ventilation v
21、entilation below the level of the heater (See also 7.3.3.) 2.4 overhead radiant heater a gas-fired appliance intended for installation above head level and designed to heat, mainly by radiation, the space in which it is installed 2.5 overhead radiant tube heater an overhead radiant heater in which a
22、 tube or series of connected tubes are heated by the internal passage of combustion products 2.6 overhead luminous radiant heater an overhead radiant heater in which the heat is produced by means of burning the fuel gas at or near the outer surface of a material such as a ceramic plaque or metal gau
23、ze Licensed Copy: London South Bank University, London South Bank University, Thu Dec 07 06:40:33 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6896:1991 2 BSI 02-1999 Section 2. Installation 3 Heat input requirements for full space heating If the heater(s) is/are specified to be the sole means of h
24、eating, (i.e. intended to provide full heating and not partial or localized heating), the rating of the heater(s) shall be adequate to: a) raise the environmental temperature to a level that the purchaser considers is necessary for the type of usage of the building; b) ensure the specified heating-u
25、p time relative to the lowest design temperature. COMMENTARY AND RECOMMENDATIONS ON CLAUSE 3. Thermal comfort and design information is contained in CIBSE guides A1 to A5. 4 Materials and components All materials and components shall comply with the following standards, as appropriate. BS 21, Specif
26、ication for pipe threads for tubes and fittings where pressure-tight joints are made on the threads (metric dimensions). BS 41, Specification for cast iron spigot and socket flue or smoke pipes and fittings. BS 143 and b) combustible materials shall not be overheated (see 12.8). COMMENTARY AND RECOM
27、MENDATIONS ON 6.1.1. The maximum radiation levels at head height (2 m) should be not more than 240 W/m2 75 Btu/(ft2h) and at floor level not more than 80 W/m2 25 Btu/(ft2h). 6.1.2 Heaters shall be suitable for the conditions in which they are to be installed, particularly in corrosive or high wind s
28、peed environments. If there is any doubt the appliance manufacturer shall be consulted. COMMENTARY AND RECOMMENDATIONS ON 6.1.2. In special working environments, such as food packing areas or areas with significant concentrations of chlorinated hydrocarbons, alternative materials for the finishes or
29、 manufacture of the heater may need to be considered. 6.1.3 Heaters shall be flued and/or have combustion air directly ducted to the burner from the outside air where vapours/gases or airborne dust are present which might cause damage to the heater/flue or might degrade to concentrations of potentia
30、lly harmful gases as specified from the time to time by the Health and Safety Executive (see publication EH/40). Licensed Copy: London South Bank University, London South Bank University, Thu Dec 07 06:40:33 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6896:1991 BSI 02-9993 COMMENTARY AND RECOMMEND
31、ATIONS ON 6.1.3. It is known that some plastics dusts, and some vapours given off during degreasing and curing processes, will when passed through a flame produce potentially harmful gases. The quantities given off and the ventilation rate of the building will determine whether the limits specified
32、in publication EH/40 are exceeded and thus require additional measures to be taken. 6.1.4 Heaters shall either be suitable protected or situated where they will not suffer external mechanical damage. 6.1.5 Adequate clearance in accordance with the manufacturers instructions shall be allowed and mean
33、s provided to give ready access for installing, operating and servicing of the burner(s), fan(s), controls and any other part(s) that require regular attention and which are not liable to accidental disconnection. 6.1.6 Adequate clearance shall be allowed between any combustible materials, or any ma
34、terial likely to be affected by high temperatures, and the appliance or flue (see 6.1.1 and clause 12). 6.1.7 Where heaters are suspended, e.g. from roof trusses, the means of suspension shall be of sufficient number and of adequate strength to support the full weight of the appliance. Any means of
35、suspension shall be protected against corrosion. 6.1.8 Where heaters are wall-mounted, they shall be fitted using sufficient brackets of adequate strength to support the full weight of the appliance. The brackets shall be protected against corrosion. 6.1.9 No installation shall be carried out unless
36、 the supporting structure is sufficiently strong to withstand the additional loads imposed by pipework, appliances and, where fitted, flue systems. 6.2 Siting where petroleum and other heavier-than-air flammable vapours are present 6.2.1 Heaters shall not be installed in spaces classified as hazardo
37、us as defined in BS 5345-2. COMMENTARY AND RECOMMENDATIONS ON 6.2.1. It should be noted that correct hazardous areas classification will normally result in the identification of distinct zones at different elevations, i.e. zones 0, 1 or 2. Consequently it may be possible to install heaters in safe a
38、reas, as defined, above zones exposed to heavier-than-air vapours/gases. Increasing the ventilation rates within hazardous areas may alter their extent and may thus permit the use of such heaters. 6.2.2 Where heavier-than-air flammable vapours may be present, cables and switchgear shall not be sited
39、 within 1.2 m of the floor level within the space to be heated. 6.2.3 An appliance for use with 3rd family gases shall not be installed in a room below ground level, e.g. in a basement or a cellar. COMMENTARY AND RECOMMENDATIONS ON 6.2.3. This does not preclude the installation of such appliances in
40、to rooms which are basements with respect to one side of the building but open to ground level on the opposite side. 7 Air supply 7.1 General 7.1.1 The supply of air for combustion shall comply with either 7.2 or 7.3. 7.1.2 Means, such as interlocks, shall be provided for installations in which the
41、incorrect operation or blockage of any fan supplying ventilation air, or extracting combustion products, fumes, etc. can lead to an insufficient supply of air or spillage. In the event of such a fan failure, the means provided shall shut down the appliance(s), their associated fans and all other equ
42、ipment that could be affected. COMMENTARY AND RECOMMENDATIONS ON 7.1.2. Consideration should be given to any precautions that may need to be taken for plant fitted with integral extract fans and systems. 7.1.3 Where other fuel-fired appliances are installed, the combustion and ventilation requiremen
43、ts of all such plant, particularly if it is unflued, shall be taken into account. 7.1.4 Where mechanical ventilation is used in conjunction with flued appliances, it shall be by mechanical inlet and either natural or mechanical extraction. 7.1.5 Mechanically supplied air inlets shall be at or below
44、the level of fuel-fired appliances. 7.1.6 Where natural ventilation is used it shall be by suitable permanent openings of free area as specified in 7.2 or 7.3 as appropriate. These openings shall communicate directly to outside and, where practicable, shall be fitted with grilles of low resistance.
45、Low-level inlets shall be below the appliance(s) and high-level outlets shall be above the appliance(s). Where high- and low-level ventilation openings are required (see 7.3.1) the vertical distance between the centre line of the high- and low-level grilles shall be not less than 3 m. Licensed Copy:
46、 London South Bank University, London South Bank University, Thu Dec 07 06:40:33 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6896:1991 4 BSI 02-1999 COMMENTARY AND RECOMMENDATIONS ON 7.1.6. In order to decrease the effect of downdraught in the buildings, high-level roof vents should be of a design
47、 to encourage upward air flow under crosswind conditions. 7.1.7 The disposition of ventilation openings shall depend on the location of appliance(s), in so far as is reasonably practicable, and they shall be sited so that they cannot easily be blocked or flooded. They shall be located, where practic
48、able, on at least two sides of the building. COMMENTARY AND RECOMMENDATIONS ON 7.1.7. Consideration should also be given to the use of ventilation near floor level where heavier-than-air gases, e.g. LPG, are distributed. 7.1.8 Ventilation air shall be taken from an outside point where it is not like
49、ly to be contaminated, e.g. by smells, road vehicle exhausts or dry-cleaner exhausts. 7.2 Flued appliances 7.2.1 Natural ventilation Low-level openings shall be provided in all cases as given in Table 1. In those special cases where the combustion air is directly ducted to the burner from the outside air, the low-level openings shall be not less than 50 % of the areas given in Table 1 (see also 6.1.3). COMMENTARY AND RECOMMENDATIONS ON 7.2.1. High-level ventilation is not generally needed for this type of flued appliance. Table 1 Ventilation openings 7.2.2 Mechanic