1、BRITISH STANDARD BS 3958-6: 1972 Incorporating Amendment No.1 Specification for Thermal insulating materials Part6: Finishing materials; hard setting composition, self-setting cement and gypsum plasterBS3958-6:1972 This British Standard, having been approved by the Refrigeration, Heating and AirCond
2、itioning Industry Standards Committee, was published under the authority ofthe Executive Board on 7 April1972 BSI 07-1999 The following BSI references relate to the work on this standard: Committee reference RHE/9 andRHE/9/4 Draft for comment70/20324 ISBN 580 07121 9 Co-operating organizations The R
3、efrigeration, Heating and Air Conditioning Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Association of Consulting Engineers Gas Council* Ass
4、ociation of Manufacturers of Domestic Heating and Ventilating Contractors Electrical Appliances Association Boiler and Radiator Manufacturers Heating and Ventilating Research Association Association HEVAC Association British Mechanical Engineering Confederation Institute of Fuel British Oil and Gas
5、Firing Equipment Institute of Refrigeration Manufacturers Association Institution of Electrical Engineers British Refrigeration and Air Conditioning Institution of Gas Engineers* Association* Institution of Heating and Ventilating Department of the Environment* Engineers* Department of Health and So
6、cial Security Lloyds Register of Shipping Electricity Council, The Central Electricity Ministry of Defence (Navy) Generating Board and the Area Boards in National Coal Board England and Wales Royal Institute of British Architects* Engineering Equipment Users Association Water-tube Boilermakers Assoc
7、iation The Government department and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Asbestos Cement Manufacturers Association Fibre Bui
8、lding Board Development British Chemical Plant Manufacturers Organization Association EurosilUK Association of Manufacturers of Combustion Engineering Association Mineral Fibre Insulation Council of British Manufacturers of Petroleum Gypsum Plasterboard Development Equipment Association Department o
9、f the Environment (Building Ministry of Defence (Combined) Research Station) Structural Insulation Association Electrical Research Association Thermal Insulation Contractors Association Amendments issued since publication Amd. No. Date of issue Comments 3287 May 1980 Indicated by a sideline in the m
10、arginBS3958-6:1972 BSI 07-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Sampling and testing 1 4 Classification 1 5 Bulk density 1 6 Wet coveting capacity 1 7 Thermal conductivity 1 8 Storage requirements 2 9 Additional requirements 2 10 I
11、nformation to be given by the purchaser and by the manufacturer 3 11 Packaging 3 12 Marking 3 13 Identification of asbestos-free material 3 Appendix A Consistency test 4 Appendix B Conditioning of test specimens 4 Appendix C Test for determination of wet covering capacity 4 Appendix D Heat resistanc
12、e test 5 Appendix E Resistance to impact test for self-setting cement 5 Figure 1 Apparatus for comparison of consistency 6BS3958-6:1972 ii BSI 07-1999 Foreword This standard makes reference to the following British Standards and Code of Practice: BS874, Methods of determining thermal properties, wit
13、h definitions of thermal insulating terms. BS2972, Methods of test for thermal insulating materials. BS3533, Glossary of terms relating to thermal insulation. BS3958, Thermal insulating materials. CP3005, Thermal insulation of pipework and equipment. This Part of this British Standard gives requirem
14、ents for certain finishing materials that are used in conjunction with the thermal insulating materials specified in other Parts of the Standard. A complementary series of British Standard 1)relating to the use of thermal insulation materials for temperatures above ambient and up to650C has been est
15、ablished to give guidance on the thickness of insulation to be used. 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 immun
16、ity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesiandii, pages1to6 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 insid
17、e front cover. 1) BS1334, “The use of thermal insulating materials for central heating and hot and cold water supply installations”. BS1588, “The use of thermal insulating materials in the temperature range95C to230C”. BS3708, “The use of thermal insulating materials between230C and650C”.BS3958-6:19
18、72 BSI 07-1999 1 1 Scope This British Standard specifies requirements for finishing materials, prepared for use by mixing with water, for application to insulating materials after they have been applied at site to the plant or piping systems. Some of these finishing materials are used for services a
19、t temperatures below ambient, in which case a vapour barrier is-required (see CP3005). NOTEThe titles of British Standards referred to in this standard are listed on page2. 2 Definitions For the purposes of this British Standard, the definitions given in BS874, BS3533 and BS3958 apply. 3 Sampling an
20、d testing Sampling and testing shall be in accordance with the appropriate clauses of BS2972, supplemented where necessary, or where demanded by the user, by additional tests, details of which are given in appendices to this standard. For the purposes of the tests in this standard, the water to weig
21、ht ratio shall be such as to give a consistency of between5 and20 revolutions as given by the results of the consistency test described in Appendix A. For conditioning prior to test, see Appendix B. 4 Classification 4.1 Finishing materials are generally supplied as dry powders which, when mixed with
22、 water in suitable proportions, are applied in plastic form and dried or set in place to form a hard, smooth surface. 4.2 Finishing materials may be classified in three main types, as follows: 1) Hard setting composition, which sets by removal of water on heating, is a mixture of inorganic fillers a
23、nd well distributed reinforcing fibres with a clay bonding agent. 2) Self-setting cement, which sets without the application of heat, consists of well distributed reinforcing fibres with a hydraulic cement as binder, with or without a plasticizing agent or fillers. 3) Gypsum plaster composition, whi
24、ch sets without the application of heat, consists of calcium sulphate hemihydrate, with the addition of well distributed reinforcing fibres, usually to a lower percentage by weight than for self-setting cement. NOTEMaterials(1) and(3) above are adversely affected by water. Material (2) is not advers
25、ely affected but may absorb and transmit water if it is allowed to lie for long periods. Materials(1) and(3) should not be used out of doors unless protected, and care should be taken in using material(2) out of doors (see CP3005). 5 Bulk density The bulk density shall be determined in accordance wi
26、th BS2972. 5.1 Hard setting composition. The density of the coating, applied and dried, shall be not greater than1 500 kg/m 3 . 5.2 Self-setting cement. The density of the coating, applied and dried, shall be not greater than1 800kg/m 3 . 5.3 Gypsum plaster composition. The density of the coating, a
27、pplied and dried, shall be not greater than1 600kg/m 3 . 5.4 Limits. For any particular product the variation from the manufacturers quoted value for bulk density shall not exceed 15%. 6 Wet covering capacity The wet covering capacity shall be determined in accordance with Appendix C. As a general g
28、uide, it will be found that the covering capacities will lie between the following ranges: 1) Hard setting composition. 10550 m 21000 kg at13mm thickness. 2) Self-setting cement. 9540 m 2 /1000 kg at13mm thickness. 3) Gypsum plaster composition. 6045 m 2 /1 000 kg at13mm thickness. NOTEThe wet cover
29、ing capacity of the self-setting cements cannot be directly related to the applied and dried density as some of the water used for mixing combines chemically with hydraulic cement. The self-setting cements, of course, vary with the manufacturer and the water of hydration will vary from material to m
30、aterial. The covering capacity over insulation may differ from figures obtained by the method described in Appendix C, which refers to a non-absorbent substrate. 7 Thermal conductivity Finishing compositions are not specifically manufactured as thermal insulants, but they do make some contribution t
31、o the thermal resistance of the insulation system. Where it is necessary to take this into account in calculations, a thermal conductivity of0.2 W/m K may be assumed.BS3958-6:1972 2 BSI 07-1999 8 Storage requirements For hard setting compositions, the maximum free moisture content shall be not great
32、er than5%. Self-setting compositions and gypsum plaster will be supplied dry and it is essential that they are maintained dry during storage. 9 Additional requirements 9.1 Homogeneity. The materials shall be thoroughly premixed and substantially free from unopened or badly distributed fibre or coars
33、e constituents. 9.2 Inertness. The material shall not include substances that will promote corrosive attack on the surfaces with which it is in contact (e.g.wire netting used as reinforcement). Attention is drawn to the effects of chlorides on austenitic steels (see CP3005). 9.3 Heat resistance. The
34、 material as applied shall not deteriorate at the maximum temperature of use. Finishing compositions and self-setting cements are normally not applied to surfaces that will be above65C, but they may come into contact with hot surfaces where the insulation is penetrated by supports or valves or termi
35、nates at boiler or furnace casings. In some applications the insulated equipment may be entirely enclosed in spaces where the ambient temperature is relatively high, with a correspondingly elevated temperature of the finishing composition. A method of test for stability at elevated temperatures is g
36、iven in Appendix D. NOTENormally, hard setting composition is not recommended for use above 150C, or gypsum plaster above50C. 9.4 Setting time. The conditions of setting should be stated by the manufacturer. NOTE 1Hard setting compositions do not contain hydraulic setting agents and setting time wil
37、l depend upon the rate at which the mixing water is either absorbed into the underlying insulation or evaporated from the surface, or both. Application is facilitated and setting time reduced when the equipment to be insulated is gently heated. Then the hard setting composition will be reasonably se
38、t in5 hours to6 hours, although complete drying may take much longer. NOTE 2Self-setting cements are hydraulic setting and only as much as can be used within1 hour should be mixed at one time. The time for the cement to take an initial set depends upon the absorbency of the underlying insulating mat
39、erial. On absorbent material the cement takes its initial set and can be compacted and finally trowelled in2 hours to3 hours. On non-absorbent or only slightly absorbent materials the initial set may take up to24 hours. Final drying out will depend on the ambient temperature. NOTE 3Gypsum plaster co
40、mpositions set much more rapidly and only as much as can be used within30 minutes should be mixed at one time. These compositions will set hard over absorbent or non-absorbent insulation materials within1 hour. 9.5 Resistance to compression. The characteristics of the insulating materials to which t
41、he finishing materials are applied vary widely both in respect of mechanical strength and adhesion between the insulation and covering. Commonly used reinforcing materials, such as wire netting, also affect the mechanical strength of the complete installation. The test specified in 7.2 of BS2972:196
42、1 may be used to determine the resistance to compression of finishing materials except that the sample size shall be75mm 75mm 25mm. For10% deformation the resistance to compression shall be not less than the following values: The density of the specimen tested shall be stated. 9.6 Flexural strength.
43、 When coating compositions are applied over resilient or easily compressed insulating materials, any loading such as may arise, for example, from a ladder placed against the surface, may cause damage by flexing the covering rather than by direct compression. The method of test of flexural strength s
44、hall be as given in BS2972, except that the specimen size shall be300mm 75mm 13mm and that the test shall be carried out on250mm centres. The flexural strength of self-setting cement shall be not less than2000 kN/m 2 . Figures for hard setting compositions and gypsum plaster vary considerably from o
45、ne manufacturer to another and manufacturers recommendations should be sought. The density of the specimens shall be stated in the test report. 9.7 Resistance to impact. The test for resistance to impact is only intended for self-setting cement and the method of test is given in Appendix E. The aver
46、age diameter of five indentations shall not exceed30mm. Any cracking of the specimen that is observed shall be reported. 9.8 Consistency of wet-mixed finishing materials. The consistency of the wet material, as prepared in accordance with the manufacturers recommendations for application, affects su
47、ch properties as ease of trowelling, wet adhesion, drying, shrinkage and density. A method of test for consistency is given in Appendix A. Hard setting composition 1000 kN/m 2 Self-setting cement 1700 kN/m 2 Gypsum plaster 800 kN/m 2BS3958-6:1972 BSI 07-1999 3 For the purposes of the tests in this s
48、tandard, the water to weight ratio shall be such as to give a consistency of between5 and20 revolutions (as given by the results of the consistency test described in Appendix A). 10 Information to be given by the purchaser and by the manufacturer 10.1 The following information shall be given by the
49、purchaser. 1) Type of finishing material required, i.e.hard setting composition or self-setting cement or gypsum plaster. 2) Whether or not the finishing material is to be asbestos-free. 3) Nature of insulation material to which finishing material is to be applied. 4) Whether heat is expected to be available at the time of application. 5) Any special features of storage conditions so that appropriate packing may be arranged, e.g.where the material may be kept in very humid conditions. 6) Any special or unusual conditions of service anticipated,
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