BS-7435-1-1991.pdf

BRITISH STANDARD BS 7435-1: 1991 Fibre cement flue pipes, fittings and terminals Part 1: Specification for light quality fibre cement flue pipes, fittings and terminals Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 This British Standard, having been prepared under the direction of the Fibre Reinforced Cement Products Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 31 July 1991 © BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference FRB/3 Draft for comment 88/13656 DC ISBN 0 580 19563 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Fibre Reinforced Cement Products Standards Policy Committee (FRB/-) to Technical Committee FRB/3, upon which the following bodies were represented: British Gas plc Fibre Cement Manufacturers Association Limited Glassfibre Reinforced Cement Association Institution of Water and Environmental Management Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 © BSI 01-2000i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Definitions1 3Composition and materials1 4Fire properties1 5Manufacture1 6Sizes and tolerances2 7Performance criteria2 8Marking3 9Instructions3 Appendix A Sizes of pipes and fittings4 Appendix B Test for transverse crushing strength8 Appendix C Test for flow resistance of terminals8 Appendix D Test for acid resistance11 Figure 1 Typical freestanding terminals and ridge terminal adaptor2 Figure 2 Straight pipe4 Figure 3 Square/obtuse bend5 Figure 4 Equal square/obtuse tee5 Figure 5 Unequal square/obtuse tee6 Figure 6 Taper piece6 Figure 7 Slip socket7 Figure 8 Loose socket for connecting fibre cement pipes of the same nominal size7 Figure 9 Blank cap7 Figure 10 Split socket with connecting strap8 Figure 11 Loading in transverse crushing test9 Figure 12 Apparatus for measuring flow resistance of freestanding terminals under wind conditions10 Figure 13 Apparatus for measuring flow resistance of ridge terminals under wind conditions11 Table 1 Tolerances4 Table 2 Straight pipes4 Table 3 Square and obtuse bends5 Table 4 Equal square and obtuse tees5 Table 5 Unequal square and obtuse tees6 Table 6 Taper pieces6 Table 7 Slip sockets7 Table 8 Loose sockets for connecting fibre cement pipes of the same nominal size7 Table 9 Blank caps7 Table 10 Split sockets with metal connecting strap7 Table 11 Flue flow rates and values of the constant X9 Publication(s) referred toInside back cover Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 ii © BSI 01-2000 Foreword This Part of BS 7435, which has been prepared under the direction of the Fibre Reinforced Cement Products Standards Policy Committee, contains dimensional and performance requirements for light quality fibre cement flue pipes, fittings and terminals. BS 7435-1 contains requirements for heavy quality fibre cement flue pipes, fittings and freestanding terminals. Tests for transverse crushing strength, flow resistance of terminals and acid resistance are given in Appendix B, Appendix C and Appendix D. The standard relates to products composed of cement based compounds including particulate fillers, reinforced with selected fibres excluding asbestos, and includes methods of test for transverse crushing strength, flow resistance of terminals and acid resistance. A British Standard 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. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 12, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 © BSI 01-20001 1 Scope This Part of BS 7435 specifies dimensional, performance and test requirements for light quality fibre cement (excluding fibres of asbestos) flue pipes, fittings and terminals of nominal sizes 75 mm, 100 mm, 125 mm and 150 mm. This quality of pipe, which is unsuitable for use where there is direct flame impingement, is intended for use with the following. a) Oil burning appliances with a rated output up to 44 kW (for space heating and hot water supply purposes) and a flue gas temperature not exceeding 260 °C. NOTE 1For further information reference should be made to BS 5410-1. b) Gas burning appliances with a rated input up to 60 kW. NOTE 2For further information reference should be made to BS 5440-1. c) Ventilation ducts and other purposes. NOTE 3For nominal sizes exceeding 150 mm for use with gas burning appliances and for fibre cement (excluding fibres of asbestos) flue pipes, fittings and freestanding terminals for use with oil burning equipment (for industrial installations) with a waste gas temperature not exceeding 230 °C, and incinerators (not exceeding 0.03 m3 in capacity) see BS 7435-2. NOTE 4The titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Part of BS 7435, the definitions given in BS 6100-2.8, BS 1179:19671) and BS 1179-61) apply, together with the following. 2.1 freestanding terminal terminal, other than a ridge terminal, designed for fitting directly to the outlet of a flue system 2.2 ridge terminal terminal designed for fitting at the ridge of a building 2.3 ridge terminal adaptor (“R”-type adaptor) fitting for connecting circular cross section pipe to the rectangular section connection of a ridge terminal 3 Composition and materials 3.1 Composition Fibre cement (excluding fibres of asbestos) flue pipes, fittings and terminals shall be made from a close and homogeneous mixture consisting of a suitable inorganic hydraulic binder, fibre, fillers and water; they shall exclude any materials liable to cause deterioration in the quality of the pipes, fittings and terminals, which shall be left in their natural colour. NOTE 1Cement complying with BS 12 is a suitable binder. NOTE 2Pipes, fittings and terminals can also be supplied with adherent sealant on their surfaces. Sealant is only applied for purposes of dust suppression. 3.2 Materials Except for fastenings and other components that do not come into direct contact with flue gases (e.g. the galvanized steel strap shown in Figure 10), metal parts that are to be incorporated in a terminal or fitting shall be manufactured from highly corrosion resistant stainless steel complying with grade 316S11, 316S13, 316S31, 316S33 or 320S31 of BS 970-1 or with grade 315S16, 316S11, 316S13, 316S31, 316S33, 317S12, 317S16, 320S31 or 320S33 of BS 1449-2. 4 Fire properties When tested in accordance with BS 476-4, pipes, fittings and terminals shall be classified as non-combustible. 5 Manufacture 5.1 General Pipes, fittings and terminals shall be in all respects sound, homogeneous and free from excrescences or other imperfections detrimental to their performance. NOTEFinished pipes, fittings and terminals should be smooth and of good appearance, their inner and outer surfaces being as nearly as practicable concentric. 5.2 Construction of terminals NOTETerminals should be designed so that they are unlikely to be blocked by leaves and/or snow and so that they minimize entry of birds, rain, snow or condensate to the flue. 5.2.1 Freestanding terminals A freestanding terminal shall be so designed that it cannot be inadvertently pushed onto a flue pipe or fitting of the same nominal size in such a manner that the terminal outlet free area is restricted. 1) Applicable to gas only. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 2 © BSI 01-2000 NOTE 1The end of the terminal that is to be connected to the flue pipe can be either a spigot or a socket type. NOTE 2Typical freestanding terminals are shown in Figure 1(a). 5.2.2 Ridge terminals If a terminal is fitted with a ridge terminal adaptor it shall be capable of being connected to the type of flue pipe recommended by the manufacturer. If the terminal is not provided with a ridge terminal adaptor it shall be provided with bolts capable of entering 8 ± 0.5 mm holes spaced at 330 ± 2 mm centres and with an opening of 45 ± 2 mm × 290 ± 10 mm to accept a typical ridge terminal adaptor. NOTEA typical “R”-type adaptor is shown in Figure 1(b). A means of sealing the terminal to the adaptor shall be described by the terminal manufacturer. The material used for this sealing shall be capable of withstanding temperatures of 20 °C to + 200 °C. 5.2.3 Ridge terminal adaptors The flue pipe end connection of the adaptor shall be a spigot type. 6 Sizes and tolerances 6.1 General Sizes of pipes and fittings shall be as shown in Appendix A. Tolerances on internal and external diameters, thicknesses and effective lengths shall be as shown in Table 1 and Figure 2. 6.2 Effective length The effective length of pipes shall be the length exclusive of the internal depth of the socket. Effective lengths shall be 900 mm, 1 200 mm and 1 800 mm subject to the tolerances given in Table 1. 6.3 Spigots and sockets of pipes, fittings and terminals Spigots and sockets of pipes, fittings and terminals shall conform to the sizes given in Table 2. 6.4 Terminals Openings in a terminal shall be such that they will admit, without distortion, a 6 mm diameter ball but not a 16 mm diameter ball. 7 Performance criteria 7.1 Density Pipes, fittings and terminals, when tested as described in clause 14 of BS 4624:1981, shall have a minimum density of 1 100 kg/m3. NOTEAll dimensions are in millimetres. Figure 1 Typical freestanding terminals and ridge terminal adaptor Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 © BSI 01-20003 7.2 Frost resistance Pipes and fittings, when tested as described in clause 17 of BS 4624:1981, shall not exhibit signs of cracking or other defects likely to impair their performance. The specimen to be tested shall be a 250 mm length of the pipe or fitting. 7.3 Straightness, regularity of thickness, and diameter The deviation from straightness of pipes when tested as described in clause 18 of BS 4624:1981 shall be not more than 3 mm in any 600 mm and shall be not more than 6 mm in 1 800 mm. The regularity of pipe thickness and diameter shall be in accordance with Table 1. 7.4 Water permeability Pipes and fittings, when subjected to a test of 0.04 N/mm2 internal hydraulic pressure by the method described in clause 19 of BS 4624:1981, shall not show any defects. 7.5 Transverse crushing strength When tested as described in Appendix B, pipes shall have a minimum transverse crushing strength of 6 N/mm2. 7.6 Flow resistance of terminals When tested for flow resistance as described in Appendix C, a flue terminal shall have a resistance factor K not greater than 5 for freestanding terminals (see 2.1), or not greater than 15 for ridge terminals (see 2.2). The tests shall be repeated whenever there is a change in design of the flue terminal. 7.7 Acid resistance When tested for acid resistance as described in Appendix D, the mass loss from any test piece shall not exceed 1.5 %. 8 Marking Each pipe, fitting and terminal shall be permanently and legibly marked with the following information: a) the manufacturers name or trade mark; b) nominal size or, in the case of a ridge terminal, the nominal size(s) of the flue for which the terminal is suitable; c) the number and date of this British Standard, i.e. BS 7435-1:19912). 9 Instructions The manufacturer shall make available the following information: a) full installation instructions; b) list of all flue pipes, fittings and terminals necessary for the installation of a complete system. 2) Marking BS 7435-1:1991 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the a claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may be also be desirable. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 4 © BSI 01-2000 Appendix A Sizes of pipes and fittings The sizes of pipes and fittings are given in Figure 2 to Figure 10 and Table 2 to Table 10. Table 1 Tolerances (see Figure 2) Table 2 Straight pipes Figure 2 Straight pipe Nominal sizeDiameter ABDiameter CDiameter EF mmmmmmmmmmmm 75 100 125 150 ± 3.0± 1.0+ 6.0, 0± 3.0+ 0, 12 Nominal sizeDiameter ABDiameter CDDiameter EF mm mm mm mm mm mm 75 100 125 150 76 102 127 152 4.5 4.5 6 6 92 118 146 172 51 64 76 89 85 111 139 164 900, 1 200 and 1 800 mm in all nominal sizes NOTE 1These sizes of sockets and spigots apply to all pipes, fittings and terminals. NOTE 2For dimensional tolerances see Table 1. Licensed Copy: London South Bank University, London South Bank University, Fri Dec 08 14:43:20 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7435-1:1991 © BSI 01-20005 Table 3 Square and obtuse bends Table 4 Equal square and obtuse tees Figure 3 Square/obtuse bend Nominal size Diameter A GÚ mm mm mm 75 100 125 150 76 102 127 152 118 149 184 216 Standard range of angles Ú 90°, 110° 120°, 135° NOTE 1For further spigot and socket details see Table 2, as appropriate. NOTE 2For other dimensions relating to each nominal size of bend see manufacturers literature. Figure 4 Equal square/obtuse tee Nominal sizeDiameter AHJÚ 90°110°120°135°90°110°120°135° mm mm mm mm mm mm mm mm mm mm 75 100 125 150 76 102 127 152 184 235 292 343 223 286 356 419 242 311 387 457 261 337 419 495 118 149 184 216 156 200 248 292 175 225 279 330 194 251 311 368 Standard range of angles Ú 90°, 110°, 120°, 135° NOTE 1For further spigot and socket details see Table 2, as appropriate. NOTE 2For other dimensions relating to each nominal size of tee see manufacturers literature. Lic