1、BRITISH STANDARD BS 2775:1987 Specification for Rubber stoppers and tubing for general laboratory use UDC 542.25 + 542.263.3:678BS2775:1987 This British Standard, having been prepared under the direction of the Rubber Standards Committee was published under the authority of the Board of BSI and come
2、s into effect on 31 December 1987 BSI 07-1999 First published October 1956 First revision January 1967 Second revision The following BSI references relate to the work on this standard: Committee reference RUM/35 Draft for comment 85/37794 DC ISBN 0 580 16138 2 Committees responsible for this British
3、 Standard The preparation of this British Standard was entrusted by the Rubber Standards Committee (RUM/-) to Technical Committee RUM/35, upon which the following bodies were represented: British Rubber Manufacturers Association British Structural Bearings Manufacturers Association Building Employer
4、s Confederation Concrete Society Department of the Environment (Building Research Establishment, Princes Risborough Laboratory) Department of Transport (Highways) Flexible Roofing Association Institute of Medical Laboratory Sciences Institution of Structural Engineers Malaysian Rubber Producers Rese
5、arch Association Ministry of Defence Royal Society of Chemistry Amendments issued since publication Amd. No. Date of issue CommentsBS2775:1987 BSI 07-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Physical requirements 1 4 Dimensions 1 5 Colour
6、 5 6 Marking of packaging 5 Appendix A Guide to the properties of each type of polymer 6 Figure 1 Dimensions for stoppers 2 Figure 2 Location of two holes in a stopper 2 Table 1 Physical property requirements 3 Table 2 Change in properties after accelerated ageing 3 Table 3 Dimensions of stoppers 4
7、Table 4 Dimensions of normal wall tubing 4 Table 5 Dimensions of heavy wall tubing 5 Publications referred to Inside back coverBS2775:1987 ii BSI 07-1999 Foreword This British Standard has been prepared under the direction of the Rubber Standards Committee and is a revision of BS2775:1967 which is w
8、ithdrawn. The materials specified in this British Standard are intended for general laboratory use and compounds in which specific properties have been enhanced for special applications are not included. Other British Standards pertaining to stoppers and/or tubing for particular applications are BS2
9、050, BS2463 and BS3212. The types of tubing specified in this British Standard are intended for use at relatively low gauge pressures, below1 bar 1) , or under vacuum. Use of the term “pressure tubing” for the heavy wall tubing specified in this British Standard is deprecated. Reinforced hoses compl
10、ying with BS5118, BS5119, BS5120, BS5121 or BS5122 are suitable for use under pressure. Attention is drawn to the fact that when elastomeric tubing is used in a vacuum system at pressures below 1 mm of mercury, the tubing tends to emit vapours which raise the pressures as if there were a leak in the
11、 system. A guide to some of the properties of the various types of polymer is included as Appendix A. For further information, such as suitability for contact with particular fluids and chemicals, the supplier or manufacturer should be consulted. The task of inserting glass tubing into rubber stoppe
12、rs has been the cause of a large number of accidents in the laboratory. Attention is therefore drawn to “Introduction to safety in the chemical laboratory” by N T Freeman and JWhitehead, published by Academic Press. A British Standard does not purport to include all the necessary provisions of a con
13、tract. 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 and ii, pages1to 6, an inside back cov
14、er 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) 1 bar 10 5Pa = 10 5N/m 2BS2775:1987 BSI 07-1999 1 1 Scope This British Standard specifies requirements for ru
15、bber used for stoppers and tubing intended for general laboratory use, and the dimensions of the stoppers and tubing. It is applicable to stoppers and tubing made from natural rubber and synthetic isoprene rubber, styrene-butadiene rubbers, chloroprene rubbers, ethylene-propylene-diene rubbers (EPDM
16、), silicone rubbers and fluorocarbon rubbers. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard, the definitions given in BS3558 apply. 3 Physical requirements 3.1 General The rubber shall comp
17、ly with the appropriate requirements given in Table 1. 3.2 Appearance and finish When examined visually, all outer surfaces of the finished product shall be homogeneous and free from porosity and grit. NOTEIn the interests of safety, manufacturers should ensure that the interior of rubber stoppers a
18、nd tubing is free from grit and other extraneous matter, porosity, voids, inclusions and other similar defects. 3.3 Change in properties after accelerated ageing The test pieces shall be aged in an air oven in accordance with BS903-A19 for168 h for natural rubber and synthetic isoprene rubber and st
19、yrene-butadiene rubbers, and for70h for the other polymers, at the appropriate temperature as follows: a) natural rubber and synthetic isoprene rubber and styrene-butadiene rubbers at70 C; b) chloroprene rubbers and EPDM at100 C; c) silicone rubbers at200 C; d) fluorocarbon rubbers at250 C. After ag
20、eing, the rubber shall comply with the appropriate requirements given in Table 2. 3.4 Test pieces The test pieces shall be taken either from the product, or from a moulded test sheet prepared from the same material as the product and vulcanized for an appropriate time and at an appropriate temperatu
21、re to achieve the same state of cure. NOTE 1In most instances it is not possible to obtain the required test pieces from the actual product and so the test pieces are taken from a moulded test sheet. NOTE 2An example of a suitable test sheet is specified in BS1674 and is a sheet approximately250 mm
22、square with a section along one side35mm to50mm wide and6.30 0.15mm thick, while the thickness of the remainder of the sheet is2.00 0.15 mm. Part of the6.30mm section may be moulded in the form of cylindrical buttons conforming to the requirements for type 1 test pieces specified in BS903-A6, for us
23、e in the determination of compression set. No additional vulcanization should be applied to the thicker section (or buttons) of the sheet. 4 Dimensions 4.1 Stoppers 4.1.1 General. The sizes of a stopper shall be designated by the nominal bottom diameter (dimension A in Figure 1). The diameters and l
24、ength of stoppers shall be as given in Table 3. NOTEThe size of stopper selected for use should provide a seal at a point between30% and60% along its length from the bottom (see Figure 1). 4.1.2 Pre-bored stoppers. Holes in pre-bored stoppers shall be parallel with the axis of the stopper. For sizes
25、5 to8 inclusive there shall be one central hole of3mm diameter and for sizes9 to13 inclusive there shall be one central hole of5mm diameter. For sizes15 to105 inclusive there shall be either one central hole of5 mm diameter or two holes each of5mm diameter, disposed as shown in Figure 2. NOTEThe hol
26、e diameters specified in4.1.2 are nominal only and the size and tolerance of glass tubing used should be carefully considered. Attention is drawn particularly to BS5895. WARNING. Caution should be exercised when inserting glass tubing into rubber stoppers. The glass tubing should be of a diameter sl
27、ightly smaller than the borer used to create the hole. During the operation of boring the hole, the borer should be lubricated with soap or grease. The glass tubing should be eased gently into the hole, using a cloth or gloves to protect the hands. With some types of borer the glass tube can be plac
28、ed inside the borer while the borer is still in the stopper. The borer can then be removed, leaving the tube in the stopper.BS2775:1987 2 BSI 07-1999 Figure 1 Dimensions for stoppers Figure 2 Location of two holes in a stopperBS2775:1987 BSI 07-1999 3 Table 1 Physical property requirements Table 2 C
29、hange in properties after accelerated ageing Property Test method and test conditions Natural rubber and synthetic isoprene rubber, styrene-butadiene rubbers and blends of these polymers Chloroprene rubbers EPDM Silicone rubbers Fluorocarbon rubbers Hardness (IRHD) Method N in BS903-A26 a 46 to 55 4
30、6 to 55 55 to 65 46 to 55 66 to 75 Tensile strength (MPa) min. BS 903-A2, using type 2 dumb-bells 10 10 10 6 10 Elongation at break (%) min. 400 350 350 300 175 Compression set (%) max. BS 903-A6, using type 1 test pieces, with lubrication of the compression plates, for a test duration of 22 h, at t
31、he appropriate temperature as follows: 70 C 150 C 200 C 30 30 30 40 40 a If the test sheet described in note2 to3.4 is used, the test piece for the determination of hardness should comprise a6.3mm thick ply on top of a2.0mm thick ply. Property Test method and test conditions Natural rubber and synth
32、etic isoprene rubber, styrene-butadiene rubbers and blends of these polymers Chloroprene rubbers EPDM Silicon rubbers Fluorocarbon rubbers Change in apparent hardness (IRHD) Method N in BS903-A26, measuring the hardness before and after ageing using a test piece comprising two2mm thick plies 0, + 5
33、0, + 10 0, + 10 0, + 10 0, + 10 Change in tensile strength (% of value before ageing) max. BS 903-A2, using type 2 dumb-bells 25 15 20 25 25 Change in elongation at break (% of value before ageing) max. 25 30 40 30 25BS2775:1987 4 BSI 07-1999 Table 3 Dimensions of stoppers 4.2 Tubing The dimensions
34、of rubber tubing shall be as given in Table 4 for normal wall tubing and Table 5 for heavy wall tubing. Table 4 Dimensions of normal wall tubing Nominal size Bottom diameter (A) Top diameter (B) Length (C) Taper mm mm mm 3 4 5 6 7 8 9 10 11 13 15 17 19 21 23 25 27 29 3.00 0.25 4.00 0.25 5.00 0.25 6.
35、00 0.25 7.00 0.30 8.00 0.30 9.00 0.30 10.00 0.30 11.00 0.40 13.00 0.40 15.00 0.40 17.00 0.50 19.00 0.50 21.00 0.50 23.00 0.50 25.00 0.50 27.00 0.60 29.00 0.60 4.50 0.25 5.80 0.25 7.00 0.30 8.00 0.30 9.00 0.30 10.50 0.40 11.50 0.40 12.50 0.40 14.00 0.40 16.00 0.40 18.00 0.50 20.30 0.50 22.50 0.50 24.
36、50 0.50 26.50 0.60 28.50 0.60 31.00 0.60 33.00 0.60 12.00 0.60 14.00 0.60 16.00 0.60 16.00 0.60 16.00 0.60 20.00 0.80 20.00 0.80 20.00 0.80 24.00 0.80 24.00 0.80 24.00 0.80 26.00 1.00 28.00 1.00 28.00 1.00 28.00 1.00 28.00 1.00 32.00 1.00 32.00 1.00 1 : 8 31 33 35 37 39 41 43 45 49 53 57 62 67 71 31
37、.00 0.60 33.00 0.60 35.00 0.60 37.00 0.60 39.00 0.60 41.00 0.80 43.00 0.80 45.00 0.80 49.00 0.80 53.00 0.80 57.00 0.80 62.00 0.80 67.00 1.00 71.00 1.00 36.00 0.60 38.50 0.60 40.50 0.80 42.50 0.80 44.50 0.80 47.00 0.80 49.00 0.80 51.00 0.80 55.00 0.80 59.50 0.80 64.00 1.00 69.00 1.00 74.00 1.00 78.00
38、 1.00 35.00 1.00 38.50 1.00 38.50 1.00 38.50 1.00 38.50 1.00 42.00 1.30 42.00 1.30 42.00 1.30 42.00 1.30 45.50 1.30 49.00 1.30 49.00 1.30 49.00 1.30 49.00 1.30 1 : 7 75 79 86 92 99 105 75.00 1.00 79.00 1.00 86.00 1.00 92.00 1.00 99.00 1.00 105.00 1.30 85.00 1.00 89.00 1.00 96.00 1.00 102.00 1.30 109
39、.00 1.30 116.50 1.30 54.00 1.30 54.00 1.30 54.00 1.30 54.00 1.30 54.00 1.30 63.50 1.60 1 : 5.5 Designation Bore Wall thickness mm mm N 3 N 5 N 6.5 N 8 N 10 N 12.5 N 16 N 20 N 25 3.00 0.40 5.00 0.50 6.50 0.70 8.00 0.70 10.00 0.70 12.50 0.80 16.00 0.80 20.00 1.00 25.00 1.00 0.75 0.35 1.50 0.35 1.50 0.
40、35 2.00 0.35 2.00 0.35 2.25 0.35 3.25 0.40 3.25 0.40 3.25 0.40BS2775:1987 BSI 07-1999 5 Table 5 Dimensions of heavy wall tubing 5 Colour The colour of the stoppers and tubing shall be as follows: a) natural rubber and synthetic isoprene rubber and blends of these with styrene-butadiene rubbers: red;
41、 b) chloroprene rubbers: grey; c) silicone rubbers: translucent, opaque white, or cream; d) other polymers: black. 6 Marking of packaging The packaging shall be marked with the following information: a) the size or designation of the product; b) the number of stoppers or length of tubing in the pack
42、; c) for pre-bored stoppers which are not supplied in transparent packs, the number of holes and the nominal size of hole; d) the type of rubber polymer; e) the name or identification mark of the manufacturer or supplier and the relevant batch code; f) a reference to this British Standard; i.e.BS277
43、5:1987 2) . Designation Bore Wall thickness mm mm H 3 H 5 H 6.5 H 8 H 10 H 12.5 3.00 0.40 5.00 0.50 6.50 0.70 8.00 0.70 10.00 0.70 12.50 0.80 3.00 0.40 4.00 0.40 5.00 0.50 6.00 0.50 7.00 0.70 8.50 0.70 2) Marking BS 2775:1987 on or in relation to a product represents a manufacturers declaration of c
44、onformity, ie a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, w
45、hich may also be desirable.BS2775:1987 6 BSI 07-1999 Appendix A Guide to the properties of each type of polymer A.1 General It is emphasized that the information given below is intended only as a very basic guide to some of the properties of the various polymers. The choice of rubber polymer type de
46、pends on the conditions under which the stopper or tubing is to be used. Particular attention should be paid to the following. a) The temperature to which the product will be subjected: consider whether the product is to be subjected to heat or whether it might be exposed for long periods at low tem
47、peratures. b) Contact with fluids and chemicals: rubbers vary in their resistance to gases and liquids and improper use may result in a deterioration of properties because of chemical attack or excessive swelling. Care should also be taken to ensure compatibility (when it applies) with foodstuffs, b
48、iological systems and other medical requirements. Detailed information on the chemical resistance of the rubbers mentioned in this standard is given in ISO technical report ISO/TR7620. A.2 Natural rubber and synthetic isoprene rubber Isoprene rubbers have a good balance of properties for most general purpose applications. They have higher resilience than most other polymers and retain flexibility at lower temperatures than other polymers. They are not suitable for use with petroleum oils a
