1、BRITISH STANDARD BS3958-2: 1982 Specification for Thermal insulation materials Part 2: Calcium silicate preformed insulation UDC 662.998:666.96:661.842.65BS3958-2:1982 This British Standard, having been prepared under the directionof the Refrigeration, Heating and Air Conditioning Standards Committe
2、e, was published under the authority ofthe Board of BSI and comesintoeffect on 31 August1982 BSI 07-1999 First published December 1965 First revision February 1970 Second revision August 1982 The following BSI references relate to the work on this standard: Committee reference RHE/9 Draft for commen
3、t80/77466 ISBN 0 580 12598 X Cooperating organizations The Refrigeration, Heating and Air Conditioning Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Association of Manufacturers of Domestic Electricity Supply Industry i
4、n England and Electrical Appliances wales* Association of Consulting Engineers Heating and Ventilating Contractors Boiler and Radiator Manufacturers Association Association Limited Hevac Association British Combustion Equipment Institute of Energy Manufacturers Association Institute of Refrigeration
5、* British Gas Corporation* Institution of Gas Engineers* British Refrigeration and Air Conditioning Lloyds Register of Shipping Association* Manufacturers Association of Radiators and Building Services Research and Information Convectors Limited Association Ministry of Defence Chartered Institution
6、of Building Services* National Coal Board Department of Energy (Energy Technology) Society of British Gas Industries Department of Health and Social Security* Water-tube Boilermakers Association* Department of the Environment (PSA) The organizations marked with an asterisk in the above list, togethe
7、r with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Albury Laboratories Limited EPS Association Asbestos Cement Manufacturers Eurisol (UK) Association of Manufacturers of Association Limited Mineral Fibre Insulation Brit
8、ish Ceramic Research Association Fibre Building Board Development British Rubber Manufacturers Organization Limited Association Gypsum Products Development Association Combustion Engineering Association Institution of Mechanical Engineers Cranfield Institute of Technology Process Plant Association D
9、epartment of Industry (National Physical Royal Institute of British Architects Laboratory) Structural Insulation Association Department of the Environment (Building Thermal Insulation Manufacturers and Research Establishment) Suppliers Association (TIMSA) Department of the Environment (Housing Therm
10、al Insulations Contractors Association and Construction) Yarsley Testing Laboratories Limited Energy Industries Council Coopted member Engineering Equipment Users Association Amendments issued since publication Amd. No. Date of issue CommentsBS 3958-2:1982 BSI 07-1999 i Contents Page Cooperating org
11、anizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 Classification 1 5 Sampling and testing 1 6 Composition 1 7 Moisture content 1 8 Physical requirements 1 9 Chemical requirements 2 10 Identification of asbestos-free material 2 11 Standard shapes and sizes 2 12 Dime
12、nsional tolerances 3 13 Marking 3 Appendix A Method of test for alkalinity 4 Table 1 Thermal conductivity values 1 Publications referred to Inside back coverBS3958-2:1982 ii BSI 07-1999 Foreword This revision of this Part of this British Standard is one of a series published under the direction of t
13、he Refrigeration, Heating and Air Conditioning Standards Committee to specify requirements for a particular range of insulating materials. It supersedes the1970 edition which is withdrawn. Other Parts of this standard are: Part 1: Magnesia preformed insulation; Part 3: Metal mesh faced mineral wool
14、mats and mattresses; Part 4: Bonded preformed man-made mineral fibre pipe sections 1) ; Part 5: Bonded mineral wool slabs (for use at temperatures above50C); Part 6: Finishing materials; hard setting composition, self-setting cement and gypsum plaster. The 1970 edition of this Part specified require
15、ments for calcium silicate preformed insulation for use up to at least650C. This edition includes both medium temperature and high temperature types for use up to at least 650C and950C respectively, with appropriate requirements for each type. A British Standard does not purport to include all the n
16、ecessary 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, pagesi andii, page
17、s1 to4, 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. 1) In course of revision.BS3958-2:1982 BSI 07-1999 1 1 Scope This Part of this British
18、 Standard specifies composition, moisture content, physical and chemical requirements for two types of calcium silicate preformed insulation (see clause4). 2 References The titles of the publications referred to in this standard are listed on the inside back cover. 3 Definitions For the purposes of
19、this Part of this British Standard, the definitions given in BS874, BS2972, BS3533, BS5422 and BS5970 apply. 4 Classification This standard covers two types of calcium silicate preformed insulation as follows. Type I: slabs, radiused and bevelled lags and pipe sections for use at temperatures up to6
20、50C or such higher temperatures recommended by the manufacturer. Type II: slabs and flat bevelled lags for use up to950C or at such higher temperatures recommended by the manufacturer. 5 Sampling and testing Sampling and testing shall be in accordance with the appropriate clause in BS2972 unless oth
21、erwise stated in this standard. For thermal conductivity determinations a flat slab shall be used for the tests. 6 Composition The material shall be composed predominantly of reacted hydrous calcium silicate reinforced with suitable fibres (see9.2, note2). 7 Moisture content When conditioned at medi
22、um humidity in accordance with40.3 of BS2972:1975, the moisture content of the material shall not exceed7.5% by mass. 8 Physical requirements 8.1 General. In the application of the physical requirements of8.3 to8.6,95% confidence limits shall apply. 8.2 Thermal conductivity. When tested in accordanc
23、e with the appropriate method of test for thermal conductivity given in BS874, at a cold face temperature within the range of10C to50C, the thermal conductivity shall not exceed the values given in Table 1. Table 1 Thermal conductivity values NOTEBS874 requires the test report to state which method
24、of test was employed, the bulk density of the material, the hot face temperature and cold face temperature, the conditioning procedure and the moisture content before and after the test. 8.3 Bulk density. The bulk density of the dry material shall lie within the range: type I:180kg/m 3to240kg/m 3 ;
25、type II:210kg/m 3to280kg/m 3 . 8.4 Flexural strength. The flexural strength shall be not less than: type I:250 kN/m 2 ; type II:250 kN/m 2 . 8.5 Compressive strength 8.5.1 Dry. The reduction in thickness shall not exceed5% under a compressive load of: type I:500kN/m 2 ; type II:550kN/m 2 . The minim
26、um load at onset of disruption 2)shall be: type I:500kN/m 2 ; type II:550kN/m 2 . 8.5.2 Wet. After18 h immersion in water, the reduction in thickness shall not exceed5% under a compressive load of: type I:170kN/m 2 ; type II:170kN/m 2 . Type I Type II Mean temperature Thermal conductivity Mean tempe
27、rature Thermal conductivity C 100 150 200 250 300 350 400 425 W/(m.k) 0.061 0.067 0.074 0.080 0.087 0.094 0.102 0.106 C 200 250 300 350 400 450 500 W/(mk) 0.074 0.080 0.087 0.094 0.102 0.110 0.120 2) This is indicated by a noticeable change in the slope of the graph obtained from an automatic record
28、ing of thickness versus load, according to2.5.3 b) of BS2972:1975.BS3958-2:1982 2 BSI 07-1999 8.6 Heat stability. When tested in accordance with BS2972 under conditions of soaking heat at increasing temperatures the material shall be deemed suitable for normal use at operating temperatures at which
29、the following requirements are met. a) Maximum linear shrinkage: type I:2% type II:2%. b) Reduction in thickness not exceeding5% under a compressive load of: type I:400kN/m 2 ; type II:400kN/m 2 . c) Minimum load at onset of disruption 3)of: type I:400kN/m 2 ; type II:400kN/m 2 . 9 Chemical requirem
30、ents 9.1 Alkalinity. When tested by the method described in Appendix A the pH value recorded shall be between9.5 and11.0. 9.2 Corrosive attack. The material shall not include significant quantities of substances that will promote corrosive attack on the surfaces with which it is to be in contact. Wh
31、ere necessary, trace quantities of water-soluble chlorides shall be estimated in accordance with section 22 of BS2972:1975. NOTE 1Water-soluble chlorides are normally present in trace quantities in commercial calcium silicates as in most thermal insulating materials. In the presence of moisture and
32、oxygen and under certain adverse metallurgical conditions chloride ions are capable of initiating stress corrosion cracking in susceptible metal alloys such as austenitic stainless steels. It is not practical to indicate a safe upper limit for chloride content since water can leach out soluble chlor
33、ides from substantial volumes of insulating materials and allow them to be concentrated at the metal-insulation interface. In addition, water from outside sources such as the process itself or wind-driven spray can substantially increase the chloride content of the insulation. In conditions potentia
34、lly conducive to stress corrosion cracking, appropriate safeguards should be adopted (see BS5970). Special forms of calcium silicate incorporating corrosion inhibitors are commercially available. NOTE 2Some organic matter may be present either in fibrous form or as a bonding agent. It is suggested t
35、hat the composition of the product be checked with the manufacturer for use in process conditions where organics may present a hazard, e.g.processes involving powerful oxidizing agents or thermal insulation on pipework and plant in a flammable atmosphere. 10 Identification of asbestos-free material
36、10.1 In order to identify those materials which are not subject to control by Government regulations, (see note), asbestos-free calcium silicate preformed insulation, manufactured in accordance with Part2 of this standard, shall be distinctively coloured yellow. The colouring matter shall remain suf
37、ficiently stable and permanent under service conditions to permit the ready identification of the outer surface of the insulation. NOTEGovernment regulations 4)concerning asbestos-containing insulation require that special precautions be observed in order to safeguard the health of individuals who a
38、re handling these materials or who are working in the vicinity. 10.2 Materials which contain asbestos fibre shall not be other than self-coloured. 11 Standard shapes and sizes 11.1 Preformed calcium silicate shall be supplied in the form of flat slabs, bevelled lags, pipe sections or radiused and be
39、velled lags, complying with the following. NOTENot all suppliers provide the full range of standard shapes and sizes listed ina) tod). Conversely other shapes and sizes may be available. Suppliers literature should be consulted for details of the range offered. a) Flat slabs: types I and II Length:6
40、00mm to1000mm Width:150mm to1000mm Thickness:25mm to100mm; b) Pipe sections: type I only Length:914mm Diameter: to fit standard mild steel pipes of external diameter up to329mm Wall thickness:25mm to75mm. c) Flat bevelled lags: types I and II Length:600mm to1000mm Major width:150mm to166mm Thickness
41、:25mm to100mm. d) Radiused and bevelled lags: type I only Length:914mm Width of outer curved surface: approximately140mm to170mm depending on radius of curvature, thickness and number of lags to fit circumference Thickness:25mm to100mm. 3) This is indicated by a noticeable change in the slope of the
42、 graph obtained from an automatic recording of thickness versus load, according to2.5.3 b) of BS2972:1975. 4) Statutory Instruments 1969, No. 690, Factories, The Asbestos Regulations 1969.BS3958-2:1982 BSI 07-1999 3 11.2 Flat slabs shall be free from warp. Mating faces shall be plane and edges shall
43、 be square to the surfaces and to one another. 11.3 Pipe sections and lags shall be concentric and free from warp. Mating faces shall be plane and ends shall correspond with a plane at right angles to the long axis. 11.4 Bevelled edges of radiused and bevelled lags shall correspond with the radii of
44、 the curved surface to be insulated. 12 Dimensional tolerances The insulation shapes shall be in accordance with the dimensions stated by the manufacturer (or supplier, as appropriate), subject to the following tolerances. a) Slabs and lags Length and width: 3mm Thickness: 1.5mm,+3mm. b) Pipe sectio
45、ns Length:3mm Inside diameter: 0mm,+5mm Thickness (average): 1.5mm,+3mm Uniformity: the local thickness at any point shall not vary from the average thickness by more than3mm. 13 Marking Each package shall be indelibly marked with the following: a) the manufacturers name, mark or symbol; b) the manu
46、facturers type designation and maximum service temperature limit: if the material contains asbestos, this shall be clearly indicated; c) the nominal dimensions; d) the number of this British Standard, i.e.BS3958-2 5) . 5) Marking BS3958-2 on or in relation to a product is a claim by the manufacturer
47、 that the product has been manufactured in accordance with the requirements of the standard. The accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification to support such claims should be addressed to the Director, Qu
48、ality Assurance Division, British Standards Institution, Maylands Avenue, Hemel Hempstead, Herts HP24SQ in the case of certification marks administered by BSI or to the appropriate authority for other certification marks.BS3958-2:1982 4 BSI 07-1999 Appendix A Method of test for alkalinity A.1 Prepar
49、ation of sample. From the bulk sample, taken in accordance with BS2972, cut five pieces, each of approximate mass5g, from separate units. Crush these pieces and mix thoroughly. A.2 Determination of pH. Weigh2g of the crushed sample and shake well for10 min with100mL of distilled water at room temperature. Leave to settle for5 min and measure the pH of the mixture, using a standard pH meter (see BS1647 and BS3145) and decanting the solution if necessary. Repeat the test on a further2g of the sample and report the mean pH
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