1、BRITISH STANDARD BS7335-1: 1991 Installation of monolithic refractories Part1: Code of practice for installation by castingBS7335-1:1991 This BritishStandard, having been prepared under the directionof the Refractory Products Standards Policy Committee, was published underthe authority of the Standa
2、rds Board and comes intoeffect on 31May1991 BSI 12-1999 The following BSI references relate to the work on this standard: Committee referenceRPM/8 Draft for comment90/35416DC ISBN 0 580 19448 5 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by t
3、he Refractory Products Standards Policy Committee (RPM/-) to Technical Committee RPM/8, upon which the following bodies were represented: British Ceramic Research Ltd. British Metallurgical Plant Constructors Association British Steel Industry Coke Oven Managers Association Combustion Engineering As
4、sociation Department of trade and Industry Energy Industries Council Engineering Equipment and Materials Users Association Institute of Refractories Engineers METCON National Federation of Master Steeplejacks and Lightning ConductorEngineers Refractories Association of Great Britain Refractory Contr
5、actors Association Amendments issued since publication Amd. No. Date CommentsBS7335-1:1991 BSI 12-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Planning 1 4 Personnel 2 5 Castable materials 2 6 Water supply 3 7 Equipment 3 8 Preparation for ca
6、sting 8 9 Casting 10 10 Replacement of unsatisfactory panels 12 11 Curing 12 12 Drying out and initial firing 13 13 Quality of the lining 13 Publication(s) referred to Inside back coverBS7335-1:1991 ii BSI 12-1999 Foreword This Part of BS7335 was prepared under the direction of the Refractory Produc
7、ts Standards Policy Committee. A code of practice for installation by gunning has also been published as BS7335-2. The purpose of this code of practice is to advise on good or recommended practice before, during and after installation of monolithic refractories. Nothing in the code should be taken a
8、s a specification for either the materials or their installation. Assessed capability. Users of this BritishStandard are advised to consider the desirability of assessment and registration of a suppliers quality systems against the appropriate Part of BS5750 by a third party certification body. A Br
9、itish 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 fr
10、ont cover, an inside front cover, pagesi andii, pages1 to14, 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.BS7335-1:1991 BSI 12-1999 1 1 Scop
11、e This code of practice describes good practice for working procedures in the installation of refractory linings by casting techniques. The code is specifically concerned with the casting of replacement linings, using refractory materials bonded by calcium aluminate cement. Major repairs, involving
12、the removal of old panels of the lining back to the shell, are also covered. Recommendations for ensuring accordance with the agreed design are included where appropriate. The casting of linings for steel chimneys is specifically described in BS4207. NOTE 1Because of the complex nature of most appli
13、cations of refractory castables, the manufacturers written instructions should always take precedence over any guidance information contained herein. The application of castables with low cement levels is not included. NOTE 2The titles of the publications referred to in this standard are listed on t
14、he inside back cover. 2 Definitions For the purposes of this code of practice, the definitions given in BS3446-1 apply, together with the following. 2.1 normal cement content mixes with a cement content of greater than10% by mass, which develop their strength by hydration, without the incorporation
15、of small quantities of electrolytes or other materials 2.2 low cement content mixes which have less than10% by mass of cement and contain very small amounts of soluble compounds whose effect is to enhance the strength developed in the finished cast body 2.3 air line a pipe, usually of flexible synth
16、etic rubber, through which compressed air is conveyed to an item of equipment 2.4 material hose a pipe, usually of flexible synthetic rubber, through which mixed castable is conveyed to a point of installation 2.5 panel a section of lining divided from its surroundings. This division may be created
17、by casting one panel against another after the first has set, or it may be separated by a small gap to allow for movement of one panel relative to the other 2.6 gauging water the amount of water required to correctly mix the castable material 2.7 anchor a device for retaining a castable in position
18、in a wall, roof or floor. Anchors may be made of ceramic or metallic material 2.8 hanger a metallic device used for fixing (usually loosely) a ceramic anchor in position 3 Planning NOTEThe installation should be planned in detail, in advance, so that work on site can proceed quickly and efficiently.
19、 The checklist in3.1 to3.18 is given as an aid in drawing up such a plan. 3.1 The safety requirements of the site should be considered, taking guidance where necessary from appropriate BritishStandards (see7.9) and publications by the Health and Safety Executive. 3.2 The extent of the job and the ti
20、me available should be determined so that the required rate of installation may be calculated and an appropriate schedule for casting prepared. Allowance should be included for any preparation of the unit which may be necessary, including the fixing of anchors, fixing forms and any intermediate dryi
21、ng-out which may be required. 3.3 The number of men required to be able to place each panel of the lining continuously and correctly in the allocated time should be established. An evaluation should be made to ensure that the proposed number of men can work in the space available and that the castab
22、le material can be conveyed to the installation point, placed and densified within the working time for the material being used. 3.4 The material storage conditions and duration should be evaluated so that suitable packaging, for example hermetically sealed drums and paper sacks, may be agreed. If p
23、ossible castable material should be ordered well in advance and a schedule for delivery to site should be agreed so that the material arrives on site just prior to installation. 3.5 A water supply of appropriate quality, capacity and temperature should be provided. 3.6 Materials handling and waste d
24、isposal facilities should be provided as appropriate for the materials and equipment involved.BS7335-1:1991 2 BSI 12-1999 3.7 The type of formwork, screed boards, formwork retention systems, scaffolding and staging required to achieve the planned installation should be determined, and prepared and p
25、ositioned prior to commencement of refractories installation. 3.8 Mixers, vibrators, other compacting equipment, conveying equipment and hoses, appropriate for the planned installation rate, should be provided. 3.9 Suitable electrical power supplies should be arranged, with due regard to voltage, fr
26、equency, current and phase requirements. Artificial lighting should be provided at all work areas and access points, if necessary. 3.10 A compressed air supply may be necessary for the conveyance of material or for the equipment used to ensure proper compaction of the castable. Existing site supplie
27、s of compressed air may be adequate in some cases but provision of an independent compressor is recommended to ensure that air supply is not lost as a result of out of area activities. Whatever source of compressed air is used a suitable moisture trap or drying system should be included to prevent d
28、amage to motor units. 3.11 If necessary, auxiliary heating or cooling should be arranged, for example space heating or water cooling of the shell of the unit to be lined. 3.12 The optimum siting of the various items of equipment for efficient operation should be decided. 3.13 A suitable welding proc
29、edure for anchors or hangers should be agreed. 3.14 The size of panels to be cast and sequence of panel installation should be decided, if not specified in the unit design. If the size and shape of the unit is suitable, square panels of1m to2m sides are usually employed. 3.15 If not already designat
30、ed (in a working drawing), the refractories manufacturer/supplier or the furnace designer should be consulted regarding the type and spacing of joints between panels, and the type and spacing of anchors. 3.16 The curing and drying out procedure to be adopted should be agreed (see clauses11 and12). I
31、n multi-layer linings, the need for drying out between installation of successive layers should be considered. 3.17 If required, a quality control procedure should be agreed for incoming materials (see clause5) and/or for the cast lining, samples taken from them or samples fabricated simultaneously
32、with them (see clause13). 3.18 If required, the quality of workmanship and the efficiency of the equipment may be assessed at the commencement of the operation. 4 Personnel Operations directly involved in installation by casting are as follows: a) mixing; b) movement; c) placement; d) compaction; e)
33、 finishing; f) demoulding; g) curing. Depending on the size and difficulty of the job, it is possible that some of these activities can be carried out by the same man, or a team may be required to execute one single activity. 5 Castable materials 5.1 Quality control These recommendations are concern
34、ed with the quality of the castable material as tested prior to installation. The quality of the cast lining, which depends on both the quality of the castable material and on the method of installation, is described in clause13. Any problem associated with the castable material will be compounded b
35、y time and expense if it remains undetected until after installation, particularly if it causes failure on commissioning or in service. It is therefore recommended that acceptable limits for appropriate properties of the castable material should be agreed between the parties concerned, and that supp
36、lies of the castable material should be sampled and tested to ensure that the agreed requirements are met. The following options may be considered for quality control of supplies of castable material. a) It may be agreed between the parties concerned that the quality control procedures of the refrac
37、tories manufacturer/supplier are adequate, particularly where an accredited quality assurance scheme is operated. (SeeBS5750). b) A scheme of sampling and testing specific to the job in hand may be agreed between the parties concerned. (See, for example, the sampling scheme and testing procedures in
38、 BS1902-7.)BS7335-1:1991 BSI 12-1999 3 If option b) is implemented, the sampling of the material is most easily carried out at some stage before final palleting or storage of the consignment, such as at the end of the manufacturers production line. Only whole bags or containers should be taken as sa
39、mples. Selected samples should be clearly marked and, where necessary, stored in accordance with the guidance in5.2 until required for the preparation of test pieces in order to avoid deterioration. 5.2 Storage All castable materials should be used as soon as possible after manufacture, since they d
40、eteriorate during storage. Storage time may be reduced by arranging for the manufacturer/supplier to deliver fresh stock at short notice, subject to allowing time for acceptance tests to be completed before use. No precise storage life can be quoted, but, as a guide, the manufacturers of most castab
41、le materials aim for a storage life of at least six months under good conditions. Castable material in torn, punctured or open containers should be discarded. If undated material is to be stored, it should be stamped with its delivery date or batch number. For prolonged storage times, the castable m
42、aterial should be kept in a clean, dry, well-ventilated building. It should be stored off the ground on a ventilated platform (e.g.a pallet) and placed under a cover (e.g.tarpaulin), arranged so as to prevent any ground moisture causing condensation or high humidity under the cover. Castable materia
43、ls should not be stored at temperatures above35 C immediately before use, as rapid setting may result. In cold conditions, the precautions given in8.5.2 may be taken. After being stored for some time, castable material from the bottom of stacks may have lumps in it. These should break down when ligh
44、tly rubbed between the fingers. If they do not, the material may have hydrated and the whole bag should be discarded. Storage life depends on many factors, including the type of aggregate, cement, additives, packaging and storage conditions. Some additives, such as accelerators or inhibitors, may th
45、emselves deteriorate in storage. Castable materials may be supplied in various types of container, from hermetically sealed drums to multi-walled paper sacks. Whilst better quality containers provide better protection in adverse storage conditions, they do not necessarily extend storage life. Some c
46、astable materials may deteriorate even when stored in hermetically sealed containers. Where the condition of castable material after storage is uncertain or any doubts exist, the refractories manufacturer/supplier should be consulted. 6 Water supply 6.1 Quality The water for mixing to make the casta
47、ble should be clean, free from harmful matter and preferably should be of drinking quality to avoid the presence of dissolved chemicals which might have adverse effects on the setting or refractory properties of the cast lining. If there is any uncertainty, samples of water should be taken for analy
48、sis (see BS3148). 6.2 Capacity The rate of flow of water at the mixer position should be adequate for the maximum demand expected during the installation. If a continuous supply of sufficient volume is not available a storage tank should be sited so that it can be replenished at a lower continuous r
49、ate but still allow the gauging water to be extracted at the rate required for adequate mixing of the castable material. 6.3 Temperature The water temperature should normally be in the range5 C to25 C. In cold conditions a heated water supply may be used (see8.5.2). 7 Equipment 7.1 General The number, type and capacity of mixers, vibrators, conveying apparatus, hoses and tanks required will be dependent on the personnel and time available to complete the installation project and the accessibility of the job. Additional standby equipment might also be necessary. Therefore
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