1、BRITISH STANDARD BS3958-1: 1982 Specification for Thermal insulation materials Part 1: Magnesia preformed insulation UDC 662.998:666.96:661.846.22BS3958-1:1982 This British Standard, having been prepared under the directionof the Refrigeration, Heating and Air Conditioning Standards Committee, was p
2、ublished under the authority ofthe Board of BSI and comes intoeffect on 31August1982 BSI 03-1999 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 comment 80/769
3、73 DC ISBN 0 580 12597 1 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 in En
4、gland 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* Br
5、itish 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 of B
6、uilding 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, together wi
7、th the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Albury Laboratories Limited Eurisol (UK) Association of Manufacturers of Asbestos Cement Manufacturers Mineral Fibre Insulation Association Limited Fibre Building Board Dev
8、elopment British Ceramic Research Association Organization Limited British Rubber Manufacturers Association Gypsum Products Development Association Combustion Engineering Association Institution of Mechanical Engineers Cranfield Institute of Technology Process Plant Association Department of Industr
9、y (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 Thermal Insulations Contr
10、actors and Construction) Association Energy Industries Council Yarsley Testing Laboratories Limited Engineering Equipment Users Association Coopted member EPS Association Amendments issued since publication Amd. No. Date of issue CommentsBS3958-1:1982 BSI 03-1999 i Contents Page Cooperating organiza
11、tions Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 Sampling and testing 1 5 Composition 1 6 Moisture content 1 7 Physical requirements 1 8 Chemical requirements 1 9 Identification of asbestos-free material 2 10 Standard shapes and sizes 2 11 Dimensional tolerances 2 12 M
12、arking 2 Appendix A Methods of test for alkalinity and composition 3 Table 1 Thermal conductivity values 1 Publications referred to Inside back coverBS3958-1:1982 ii BSI 03-1999 Foreword This revision of this Part of this British Standard is one of a series published under the direction of the Refri
13、geration, Heating and Air Conditioning Standards Committee to specify requirements for a particular range of insulating materials. It supersedes the 1970 edition which is withdrawn. Other Parts of this standard are: Part 2: Calcium silicate preformed insulation; Part 3: Metal mesh faced mineral wool
14、 mats and mattresses; Part 4 1) : Bonded preformed man-made mineral fibre pipe sections; Part 5: Bonded mineral wool slabs (for use at temperatures above50C); Part 6: Finishing materials; hard setting composition, self-setting cement and gypsum plaster. A British Standard does not purport to include
15、 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
16、and ii, pages1 to 4, 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 theinside front cover. 1) In course of revision.BS3958-1:1982 BSI 03-1999 1 1 Scope This Part of
17、this British Standard specifies composition, moisture content, physical and chemical requirements for magnesia preformed insulation slabs, lags and pipe sections, generally for use up to about315 C. 2 References The titles of the standards publications referred to in this standard are listed on the
18、inside back cover. 3 Definitions For the purposes of this Part of this BritishStandard, the definitions given in BS874, BS2972, BS3533, BS5422 and BS5970 apply. 4 Sampling and testing Sampling and testing shall be in accordance with the appropriate clause in BS2972 unless otherwise stated in this st
19、andard. For thermal conductivity determinations a flat slab shall be used for the tests. 5 Composition The material shall consist of a mixture of not less than85% by mass of light basic magnesium carbonate with well-opened reinforcing fibres evenly distributed (see8.2, note 2). 6 Moisture content Wh
20、en tested in accordance with 40.1 of BS2972:1975 the moisture content of the material as received shall not exceed5% by mass. 7 Physical requirements 7.1 General. In the application of the physical requirements of7.3 to 7.6,95% confidence limits shall apply. 7.2 Thermal conductivity. When tested in
21、accordance with the appropriate method of test for thermal conductivity given in BS874, 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 of test was employed, the bulk density of the ma
22、terial, the hot face temperature and cold face temperature (generally within the range15C to30C), the conditioning procedure and the moisture content before and after the test. 7.3 Bulk density. The bulk density of the dry material shall lie within the range175kg/m 3to225kg/m 3 . 7.4 Flexural streng
23、th. The flexural strength shall be not less than250kN/m 2 . 7.5 Compressive strength. The reduction in thickness shall not exceed5% under a compressive load of350kN/m 2 . 7.6 Heat stability. When tested in accordance with BS2972 under conditions of soaking heat at increasing temperatures the materia
24、l shall be deemed suitable for normal use at operating temperatures at which the following requirements are met: a) linear shrinkage 2% maximum; b) reduction in thickness not exceeding5% under a compressive load of200kN/m 2 . 8 Chemical requirements 8.1 Alkalinity. When tested by the method describe
25、d in Appendix A the pH value recorded shall be between9.5and11.0. 8.2 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. Where necessary, trace quantities of water-soluble chlorid
26、es shall be estimated in accordance with section 22 of BS2972:1975. NOTE 1Water-soluble chlorides are normally present in trace quantities in magnesia preformed insulation as in most thermal insulating materials. In the presence of moisture and oxygen, and under certain adverse metallurgical conditi
27、ons, chloride ions are capable of initiating stress corrosion cracking in susceptible metal alloys such as austenitic stainless steels. It is not practicable to indicate a safe upper limit for chloride content since water can leach out soluble chlorides from substantial volumes of insulating materia
28、ls 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 potentially conducive to stress corrosion cracking, appropr
29、iate safeguards should be adopted (see BS 5970). NOTE 2Some organic matter may be present either in fibrous form or as a bonding agent. It is suggested that the composition of the product be checked with the manufacturer for use in process conditions where organics may present a hazard, e.g.processe
30、s involving powerful oxidizing agents, or thermal insulation on pipework and plant in a flammable atmosphere. Mean temperature Thermal conductivity C W/(mK) 50 0.059 100 0.064 150 0.070 180 0.074BS3958-1:1982 2 BSI 03-1999 9 Identification of asbestos-free material 9.1 In order to identify those mat
31、erials that are not subject to control by Government regulations, (seenote), asbestos-free magnesia preformed insulation, manufactured in accordance with Part 1 of this standard, shall be distinctively coloured pink/red. The colouring matter shall remain sufficiently stable and permanent under servi
32、ce conditions to permit the ready identification of the outer surface of the insulation. NOTEGovernment regulations 2)concerning asbestos-containing insulation require that special precautions be observed in order to safeguard the health of individuals who are handling these materials or who are wor
33、king in the vicinity. 9.2 Materials which contain asbestos fibre shall not be other than self-coloured. 10 Standard shapes and sizes 10.1 Preformed magnesia shall be supplied in the form of flat slabs, bevelled lags, pipe sections or radiused and bevelled lags complying with the following. NOTENot a
34、ll suppliers provide the full range of standard shapes and sizes listed in a) to d). Conversely other shapes and sizes may be available. Suppliers literature should be consulted for details of the range offered. a) Flat slabs Length:914mm Width:150mm to305mm Thickness:25mm to100mm. b) Pipe sections
35、Length:914mm Diameter: to fit standard pipes of external diameter up to329mm Wall thickness:25mm to75mm. c) Bevelled lags Length:914mm Major width:75mm to150mm Thickness:25mm to100mm. d) Radiused and bevelled lags Length:914mm Width of outer curved surface: approximately140mm to170mm depending on ra
36、dius of curvature, thickness and number of lags to fit circumference. 10.2 Flat slabs shall be free from warp. Mating faces shall be plane and edges shall be square to the surfaces and to one another. 10.3 Pipe sections and lags shall be concentric and free from warp. Mating faces shall be plane and
37、 ends shall correspond with a plane at right angles to the long axis. 10.4 Bevelled edges of radiused and bevelled lags shall correspond with the radii of the curved surface to be insulated. 11 Dimensional tolerances The insulation shapes shall be in accordance with the dimensions stated by the manu
38、facturer (or supplier, as appropriate), subject to the following tolerances. a) Slabs and lags Length and width:3mm Thickness: 1.5mm, +3mm. b) Pipe sections Length: 3mm Inside diameter: 0, +5mm Thickness (average): 1.5mm, +3mm Uniformity: the local thickness at any point shall not vary from the aver
39、age thickness by more than3mm. 12 Marking Each package shall be indelibly marked with the following: a) the manufacturers name, mark or symbol; b) the manufacturers type designation and maximum service temperature limit: if the material contains asbestos, this shall be clearly indicated; c) the nomi
40、nal dimensions; d) the number of this British Standard, i.e.BS3958/1 3) . 2) Statutory Instruments 1969, No. 690, Factories, The Asbestos Regulations 1969. 3) Marking BS3958/1 on or in relation to a product is a claim by the manufacturer that the product has been manufactured in accordance with the
41、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, Quality Assurance Division, British Standards Institution, Maylan
42、ds Avenue, Hemel Hempstead, Herts HP2 4SQ in the case of certification marks administered by BSI or to the appropriate authority for other certification marks.BS3958-1:1982 BSI 03-1999 3 Appendix A Methods of test for alkalinity and composition A.1 Preparation of sample. From the bulk sample, taken
43、in accordance withBS2972, cut five pieces, each of approximate mass7g, from separate units. Crush these pieces and mix thoroughly. A.2 Determination of pH. Weigh2g of the crushed sample and shake well for10min with100mL of distilled water at room temperature. Leave to settle for5min and measure the
44、pH of the mixture, using a standard pH meter (seeBS1647and BS3145) and decanting the solution if necessary. Repeat the test on a further2g of the sample and report the mean pH value. A.3 Check on composition A.3.1 General. If it is considered desirable to determine fibre or magnesia contents, the fo
45、llowing methods are suitable. A.3.2 Fibre content. Dry and weigh up to30g of the remainder of the crushed sample, transfer to a beaker, add200mL of distilled water and30mL of glacial acetic acid. Boil gently for10min, filter by suction through a Buchner funnel and wash with distilled water. Dry the
46、residue to constant mass at105C to110C. Mass of fibre in sample (in%) A.3.3 Magnesium oxide content. Transfer the filtrate and washings from A.3.2 to a calibrated2L flask and dilute to the mark. Mix well and withdraw suitable aliquots for the determination of magnesia by titration with diaminoethane
47、-tetra-acetic acid (EDTA) 4) . Calculate as a percentage by mass of the weighed sample. 4) A method for the determination of magnesia, using EDTA, is given in BS 1902-2A. mass of residue mass of sample -100. =4 blankBS3958-1:1982 BSI 03-1999 Publications referred to BS874, Methods for determining th
48、ermal insulating properties, with definitions of thermal insulating terms. BS1647, pH scale. BS1902, Methods of testing refractory materials. BS1902-2A, Chemical analysis of high silica and aluminosilicate materials. BS 2972, Methods of test for inorganic thermal insulating materials. BS 3145, Speci
49、fication for laboratory pH meters. BS 3533, Glossary of terms relating to thermal insulation. BS 5422, Specification for the use of thermal insulating materials. BS 5970, Code of practice for thermal insulation of pipework and equipment. BS 3958, Specification for thermal insulation materials 5) . BS 3958-2, Calcium silicate preformed insulation. BS 3958-3, Metal mesh faced mineral wool mats and mattresses. BS 3958-4, Bonded preformed man-made mineral fibre pipe sections 6) . BS 3958-5, Bonde
