BS 3463-1975 Specification for observation and gauge glasses for pressure vessels《压力容器水位观察和玻璃量杯规范》.pdf

1、BRITISH STANDARD BS 3463:1975 Specification for Observation and gauge glasses for pressure vessels UDC 666.11.025:621.183.31:681.128:621.642:66.023BS3463:1975 This British Standard, having been approved by the Glass Industry Standards Committee,was published underthe authorityof the Executive Boardo

2、n 31October1975 BSI 07-1999 First published January 1962 First revision October 1975 The following BSI references relate to the work on this standard: Committee reference GLC/4 Draft for comment 73/52683 ISBN 0 580 08636 4 Co-operating organizations The Glass Industry Standards Committee, under whos

3、e supervision this British Standard was prepared, consists of representatives from the following scientific and industrial organizations. British Glass Industry Research Association British Lampblown Scientific Glassware Manufacturers Association British Plastics Federation Department of the Environ

4、ment Flat Glass Manufacturers Association* Glass Manufacturers Federation Scientific Instrument Manufacturers Association Society of Glass Technology University of Sheffield (Department of Glass Technology) The industrial organization marked with an asterisk in the above list, together with the foll

5、owing, was directly represented on the committee entrusted with the preparation of this British Standard: British Valve Manufacturers Association Chemical Industries Association Council of British Manufacturers of Petroleum Equipment Department of Trade Electricity Supply Industry in England and Wal

6、es Engineering Equipment Users Association Institution of Mechanical Engineers Society of Chemical Industry Amendments issued since publication Amd. No. Date of issue CommentsBS3463:1975 BSI 07-1999 i Contents Page Co-operating organizations Inside front cover Foreword iii Section 1. General 1 1 Sco

7、pe 1 2 References 1 3 Definitions 1 4 Marking 1 Section 2. Tubular glasses for level gauges 2 5 Material 2 6 Quality of glass 2 7 Dimensions 2 8 Finish of ends 2 9 Straightness 2 10 Ovality 2 11 Thermal shock requirements 2 Section 3. Protector glasses for tubular gauge glasses 2 12 Material 2 13 Qu

8、ality of glass 2 14 Dimensions 2 15 Finish of edges 3 16 Inspection under polarized light 3 17 Thermal shock requirements 3 Section 4. Through-vision and reflex glasses 3 18 Material 3 19 Quality of glass 3 20 Dimensions and shape 3 21 Flatness 4 22 Joint faces and edges for reflex glasses 4 23 Insp

9、ection under polarized light 4 24 Thermal shock requirements 4 Section 5. Circular sight and light glasses 4 25 Material 4 26 Quality of glass 4 27 Dimensions 4 28 Finish of edges 5 29 Inspection under polarized light 5 30 Thermal shock requirements 5 Section 6. Port gauge glasses as used in fitting

10、s for steam boilers 5 31 Material 5 32 Quality of glass 5 33 Dimensions 5 34 Tolerances 6 35 Finish of faces and edges 6 36 Inspection under polarized light 6 37 Thermal shock requirements 6 Section 7. Inspection and thermal shock testing of toughened glasses and tubular glasses 6 38 Inspection 6BS3

11、463:1975 ii BSI 07-1999 Page 39 Thermal shock testing 6 Appendix A Information and recommendations on glasses for pressure vessels 9 Appendix B Information to be given when ordering 10 Figure 1 Designs for edges of protector glasses 12 Figure 2 Annealed soda-lime glass (design bending stress7MN/m 2

12、) 13 Figure 3 Toughened soda-lime glass (design bending stress35MN/m 2 ) 14 Figure 4 Annealed borosilicate glass (design bending stress7MN/m 2 ) 15 Figure 5 Toughened borosilicate glass (design bending stress14MN/m 2 ) 16 Table 1 Diameters, thicknesses and tolerances of tubular glasses 2 Table 2 Len

13、gths of protector glasses for tubular gauge glasses 3 Table 3 Dimensions and tolerances for through-vision and reflex glasses 3 Table 4 Flatness limits for through-vision and reflex glasses 4 Table 5 Preferred thicknesses of circular sight and light glasses 4 Table 6 Limits of bow for circular sight

14、 and light glasses 5 Table 7 Summary of thermal shock testing 8 Table 8 Recommended maximum working temperatures and temperaturedifferentials for through-vision and reflex glasses and circularsightand light glasses 9 Publications referred to Inside back coverBS3463:1975 BSI 07-1999 iii Foreword This

15、 British Standard was first prepared in1962 at the request of the steam using (power) and chemical industries and with the support and participation of manufacturers and users of observation and gauge glasses fitted to pressure vessels containing steam and water or other fluids. The Technical Commit

16、tee representing these interests which prepared the standard based the requirements on the characteristics of glasses which had been shown to meet adequately the demands of service under conditions of high pressure and temperature in contact with corrosive fluids. Attention was drawn to the requirem

17、ents of the Factories Act,1961, Section32(2)(d) in relation to protector glasses for gauge glasses. Recommendations for the use of observation and gauge glasses on pressure vessels are given inAppendix A, but no attempt has been made to deal exhaustively with this subject, for which both reference t

18、o suitable modern textbooks and practical experience are indispensable. The main changes incorporated in this revision as compared with the1962 edition are the following. a) In the1962 edition, ranges of standard dimensions for each type of glass were specified with the object of reducing the number

19、 of such sizes to be manufactured and kept in stock. In this revision, the need to increase the number of sizes has been recognized. b) Since 1962, liquid level indicators of the through-vision type having circular ports (referred to for example in BS759 “Valves, gauges and other safety fittings for

20、 application to boilers and to piping installations for and in connection with boilers”), have gained worldwide acceptance, and specifications for the circular glasses used therein have now been included. c) The use of soda-lime glass for tubular glasses and annealed borosilicate glass for through-v

21、ision and reflex glasses is no longer permitted. d) The section on inspection and thermal shock testing of toughened glasses (which was originally given in an appendix) now contains mandatory methods and criteria and accordingly this material has been incorporated into the main body of the standard.

22、 e) Dimensions and units have been converted to metric units. For design stress the MN/m 2 1)has been used; for fluid pressure, however, the bar 2)has been adopted. f) At the time of preparation of this British Standard, much borosilicate glass was still being supplied in imperial measure. In view o

23、f the stocks of these glasses and the expectation of their use continuing for a period before the changeover to metric sizes is complete, the thicknesses of borosilicate circular sight and light glasses are given in the former inch sizes but expressed in millimetres. In some cases the difference bet

24、ween the imperial and nearest metric equivalent is too large to ignore in design calculations, and it was therefore thought important in this revision to give (inAppendix A) recommended maximum pressures in graphical form to facilitate interpolation. g) Appendix B now lists separately the informatio

25、n to be provided with an order or enquiry. 1) 1MN/m 2 =1MPa. 2) 1 bar = 10 5 N/m 2 =100kPa.BS3463:1975 iv BSI 07-1999 Certification. It is strongly recommended that in view of the nature of this specification manufacturers and purchasers should make use of the certification facilities described on t

26、he inside back cover of this standard. 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. Su

27、mmary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to16, 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

28、 cover.BS3463:1975 BSI 07-1999 1 Section 1. General 1 Scope This British Standard specifies requirements for the main types of observation and gauge glasses for pressure vessels, and also specifies inspection and testing techniques for toughened glasses, under the following main headings. 2 Referenc

29、es The title of the British Standard referred to in this standard is given on the inside back cover. 3 Definitions For the purposes of this British Standard, the following definitions apply. 3.1 annealed glass glass which has had objectionable stresses removed by controlled heating and cooling 3.2 t

30、oughened glass (heat-treated glass, tempered glass, hardened glass) glass, the surface of which has been rapidly cooled from near its softening point, so that after cooling a residual compressive stress remains in the surface and is balanced by tensile stresses below the surface. This increases the

31、mechanical strength and thermal shock resistance of the glass and also, when it breaks, causes it to shatter into smaller and less angular fragments than an annealed glass. Chemically toughened glass is not permitted within the scope of this British Standard 3.3 “as drawn” glass glass tubing in the

32、“as made” state, not having been furnace annealed, and containing certain desirable residual stresses, in particular compression stress in the outer surface. For design purposes, stress values for annealed glasses (seeA.3.2) may be used 3.4 soda-lime glass glass in which the main constituents are si

33、lica, soda and lime. Soda-lime glass has a relatively high coefficient of expansion and hence in the annealed state has only little resistance to thermal shock but its strength and thermal resistance can be greatly increased by toughening 3.5 borosilicate glass silicate glass containing boron as a c

34、haracteristic constituent. Borosilicate glass has a relatively low coefficient of expansion and hence has considerable resistance to thermal shock. Because it has a low coefficient of expansion, it does not develop as much stress as soda-lime glass under comparable toughening treatments. Because of

35、its higher softening temperature, borosilicate glass withstands higher duty temperatures than does soda-lime glass without de-toughening. Because it is more resistant to corrosion than soda-lime glass, borosilicate glass is recommended for all reflex glasses 3.6 defects defects that may occur in gla

36、ss and affect its performance, as listed and defined in BS3447 3.7 corrosion chemical and mechanical attack of glass surfaces by the contents of the pressure vessel NOTEOwing to the difficulty of distinguishing corrosion and erosion as separate processes, the term corrosion is used to cover both pro

37、cesses. 4 Marking Glasses for which compliance with this standard is claimed shall be permanently marked with the following inscriptions: a) The manufacturers identification or trade mark. b) The number of this British Standard, i.e.“BS3463”. These markings shall not interfere with the function of t

38、he glass and preferably shall be placed so as to be visible when mounted. This latter requirement does not apply to through-vision and reflex glasses as described in section4 nor to port gauge glasses as described in section6. Section 1 General Section 2 Tubular glasses for level gauges Section 3 Pr

39、otector glasses for tubular gauge glasses Section 4 Through-vision and reflex glasses Section 5 Circular sight and light glasses Section 6 Port gauge glasses as used in fittings for steam boilers Section 7 Inspection and thermal shock testing of toughened glasses and tubular glassesBS3463:1975 2 BSI

40、 07-1999 Section 2. Tubular glasses for level gauges 5 Material Tubular glasses shall be made of borosilicate glass. It is recommended that for steaming conditions, tubular glasses should not be used above18.5bar 3)For non-steaming conditions higher pressures are allowable up to a limit of30bar. Tub

41、ing used for steaming conditions shall be in the “as drawn” state and not annealed. Tubing used for non-steaming conditions may be “as drawn” or annealed. NOTERequirements are not specified for toughened tubular glasses, as the manufacture of these is not practicable at present. 6 Quality of glass T

42、ubular glasses shall be free from defects that would interfere with vision or service. 7 Dimensions 7.1 Diameters and wall thicknesses of tubular glasses shall be as specified inTable 1. Each of the three sizes is available with two different tolerances on diameter, the two grades being designated “

43、selected grade” and “ordinary grade”. 7.2 The lengths of tubular glasses are determined by the design of the fittings into which they are assembled. For steaming applications, such fittings should not be further than505mm apart if the glass is unsupported, or600mm apart if an intermediate support is

44、 used. For non-steaming applications, the corresponding distances should be1000mm and1200mm. For the purposes of this British Standard the respective lengths of tubular glasses shall be505mm,600mm,1000mm and1200mm. Unless otherwise agreed between purchaser and manufacturer, the tolerance on length s

45、hall be 2.0mm. 8 Finish of ends The ends of tubular gauge glasses shall be cut at right angles to the axis, then fused and flame cooled to prevent severe ring stress. 9 Straightness Tubular glasses shall be straight within limits agreed between purchaser and manufacturer. Table 1 Diameters, thicknes

46、ses and tolerances of tubular glasses 10 Ovality The maximum and minimum external diameters of any cross section at right angles to the axis of tubular glasses shall not differ by more than3% of the nominal diameter. 11 Thermal shock requirements Manufacturers shall certify that tubular glasses for

47、steaming conditions will pass the thermal shock test and acceptance conditions described in section7. In the event of a purchaser requiring tests to be made on any consignment, the sampling procedure described in section7 shall be adopted. NOTEWith tubular glasses, it is not practicable to require d

48、estructive tests on small batches(10glasses or fewer) because a sampling procedure is not considered appropriate at this level. Glasses subjected to the test shall be destroyed after the test to prevent them being inadvertently put into service. Section 3. Protector glasses for tubular gauge glasses

49、 12 Material Protector glasses shall be made of toughened soda-lime clear glass. Annealed or chemically toughened glass shall not be used. 13 Quality of glass Protector glasses shall be free from defects that would interfere with vision or service. 14 Dimensions 14.1 Protector glasses should preferably be57 0.5mm wide, and12 0.5mm thick. 14.2 The length of protector glasses should preferably be as specified inTable 2 with a tolerance in each case of 0.8mm. 3) 1 bar = 10 5N/m 2= 100 kPa. Nominal external diameter Tolerance on external diame