1、BRITISH STANDARD BS 756:1952Incorporating Amendment Nos. 1 and 2Dean and stark apparatusCONFIRMED DECEMBER 2007BS 756:1952This British Standard, having been approved by the ScientificGlassware and RelatedLaboratory ApparatusIndustry StandardsCommittee and endorsed by the Chairman of the Chemical Div
2、isional Council, was published under the authority of the GeneralCouncil on 5December 1952 BSI 03-2000First published November 1937First revision May 1939Second revision December 1952ISBN 0 580 35247 1Co-operating organizationsThe Scientific Glassware and Related Laboratory Apparatus Industry Standa
3、rds Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations:Admiralty*Air MinistryAssociation of British Chemical Manufacturers*Association of Scientific WorkersBoard of T
4、radeBritish Association for the Advancement of Science*British Chemical Ware Manufacturers Association*British Laboratory Ware Association*British Lampblown Scientific Glassware Manufacturers Association*British Pharmacopia Commission*British Scientific Instrument Research AssociationChemical Societ
5、y*Department of the Government Chemist*D.S.I.R. Chemical Research LaboratoryGlass Manufacturers Federation*Institute of Petroleum*Ministry of EducationMinistry of Health*Ministry of Supply*National Physical Laboratory*Oil Companies Materials CommitteePharmaceutical Society of Great BritainRoyal Inst
6、itute of Chemistry*Science Masters AssociationSociety of Chemical IndustrySociety of Glass Technology*Society of Public Analysts and Other Analytical Chemists*Standardization of Tar Products Tests Committee*The Government departments and scientific and industrial organizations marked with an asteris
7、k in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard:Association of Hospital Management CommitteesD.S.I.R. Fuel Research StationD.S.I.R. Road Research LaboratoryGuild of Public PharmacistsMetropolitan Wat
8、er BoardOffice of the High Commissioner for IndiaOil and Colour Chemists AssociationResearch Association of British Paint, Colour and Varnish ManufacturersUniversity of London (Faculty of Science)Individual manufacturersAmendments issued since publicationAmd. No. Date of issueComments1778 December 1
9、9534882 July 1985 Indicated by a sideline in the marginBS 756:1952 BSI 03-2000 iContentsPageCo-operating organizations Inside front coverForeword ii1Scope 12Assembly of apparatus 13Material 14Design and dimensions 15Distillation vessel 16Condenser 17Receiver 1Appendix Testing of BS Dean and Stark re
10、ceivers5Figure 1 Typical assembly of Dean and Stark apparatus 6Figure 2 Flanged joint suitable for use with metal distillation vessel 7Figure 3 Condenser 8Figure 4 Spray tube 9Figure 5 2 ml. receiver 10Figure 6 7.5 ml. receiver 11Figure 7 10 ml. receiver 12Figure 8 25 ml. receiver without stopcock 1
11、3Figure 9 25 ml. receiver with stopcock 14Figure 10 100 ml. receiver 15Figure 11 3 ml. Type 2 receiver 16Figure 12 12.5 ml. Type 2 receiver 17Table 1 Sizes and connections of receivers for dean and stark apparatus 2Table 2 Mandatory dimensions and tolerances for dean and stark receivers2Table 3a Rec
12、ommended dimensions for dean and stark receivers (Types 1 and 2) 3Table 3b Recommended dimensions for dean and stark receivers (Type 2 only) 4BS 756:1952ii BSI 03-2000ForewordThis standard makes reference to the following British Standards:BS 572, Interchangeable conical ground glass joints. BS 1751
13、, General purpose glass stopcocks. Apparatus of the Dean and Stark type was first specified in 1936, when BS 614 “ Graduated receivers for Dean and Stark apparatus” was published. At that time ground glass joints were not specified, but in 1937 was added BS 756, “ Apparatus for the determination of
14、small quantities of water by distillation with an immiscible liquid”, which included requirements for condenser, receiver and flask with ground joint connections.In 1939, when the two specifications were combined as a revision of BS 756, standard ground joints were becoming popular, but were still c
15、onsidered somewhat of a luxury in many laboratories; although it was recognized that their use afforded greater accuracy in the apparatus in question, it was still considered advisable on the score of cheapness to provide for the use of corks, despite their shortcomings. In the present revision, how
16、ever, standard joints only are specified for the connection to the condenser, although there is, for most sizes, a choice of standard joint or cork for the connection to the distillation vessel.A further change is the introduction of the B19 joint for the connection between condenser and receiver. W
17、hereas the joints previously specified (A16 for the condenser and B16 for the receiver) were practically confined to this apparatus, the B19 joint is very widely used; a condenser from the laboratory stock with a B19 joint can therefore be employed in an emergency if the Dean and Stark condenser is
18、not available. This change will not, however, render obsolete any older apparatus that may still be in use.Investigations have shown that two sizes of condenser are not normally required for the apparatus, and a jacket length of 25 cm. has therefore been standardized in place of the 20 cm. and 30 cm
19、. sizes previously in use. A single size of spray tube is likewise specified, and it is emphasized that this is an optional part of the apparatus.Additional receivers have been included as developed by the Road Research Laboratory for tests on soils. These are the 25 and 100 ml. receivers with stopc
20、ock (each with a plain vapour tube for cork connection).In the 1939 edition the distance which separated the vapour tube from the body of the receiver was fixed at 70 mm. but experience has shown that this may result in the base of the receiver being unduly close to the source of heat under the dist
21、illation vessel. It has therefore been decided, for all Type 1receivers, except the 2ml. size, to revert to the 150 mm. separation originally specified in 1936 in BS 614.The Type 2apparatus of the 1939 edition has been replaced by the modified Dean and Stark type specified by the Institute of Petrol
22、eum for the determination of motor fuel diluent in crankcase oil, which may also be used for the determination of water, using a heavier liquid. As such liquids, e.g. trichlorethylene or perchlorethylene, are generally non-inflammable this apparatus may commend itself in many laboratories owing to t
23、he absence of the fire hazard. The 12.5 ml. size is that specified by the Institute of Petroleum and a3ml. size has been added for the convenience of other users.Little information on assembly of apparatus or on methods of use has been included in this standard as these points are generally dealt wi
24、th in the test methods which require the use of the apparatus.BS 756:1952 BSI 03-2000 iiiThe following British Standards make reference to an apparatus of the Dean and Stark type. Consultations have taken place with committees of the Institution which are responsible for the production of these stan
25、dards, and it is understood that the appropriate size and type of apparatus herein described can be satisfactorily employed in each case, and will be proposed for inclusion in future revisions. Agreement has also been reached with the Institute of Petroleum and the Standardization of Tar Products Te
26、sts Committee to adopt British Standard apparatus for inclusion in future editions of their handbooks on methods of test.BS 76:1943, Tars for road purposes. BS 209:1947, Fuels for oil engines. BS 241:1935, White oil pastes for paints. BS 261:1936, Ready mixed paints (oil gloss). BS 331:1938, Driers
27、for paints. BS 390:1938, Oil pastes (excluding white lead, zinc oxide and lithopone) for paints. BS 517:1948, Cresylic acid of specified orthocresol content. BS 521:1948, Cresylic acid of specified metacresol content. BS 523:1948, Phenol. BS 524:1948, Refined cresylic acid. BS 544:1934, Linseed oil
28、putty. BS 598:1950, Sampling and examination of bituminous road mixtures. BS 618:1935, Emulsions of road tar and of road tar-asphaltic bitumen mixtures for penetration (grouting and semi-grouting) and surface dressing. BS 628-32 and BS 650-56:1950, Vegetable oils. BS 684:1950, Methods of analysis of
29、 oils and fats. BS 735:1944, Sampling and analysis of coal and coke for performance and efficiency tests on industrial plant. BS 742:1947, Fuel oils for burners. BS 929:1947, Ready mixed oil paints. BS 1011:1942, Red lead ready mixed paints. BS 1016:1942, Methods for the analysis and testing of coal
30、 and coke. BS 1017:1942, Methods for the sampling of coal and coke. BS 1033:1942, Priming paint (lead base) for the protection of steel sheet. BS 1067:1942, Coal tar pitch felt damp-proof courses for temporary war-time building. BS 1070:1942, Black paint (tar base) for use on iron and steel. BS 1177
31、:1944, Pitch mastic flooring incorporating lake asphalt. BS 1375:1947, Coloured pitch mastic flooring. BS 1450:1948, Black pitch mastic flooring. BS 1469:1948, Coal tar liquid fuels. BS 1673-2, Methods of testing raw rubber and unvulcanized compounded rubber: Methods of chemical analysis. BS 1715:19
32、51, Methods for the analysis of soaps. BS 1737:1951, Jointing materials and compounds for water, town gas and low-pressure steam installations. BS 756:1952iv BSI 03-2000BS 434:1952, “ Bitumen road emulsion for penetration (grouting and semi-grouting) and surface dressing”, also specifies an apparatu
33、s of the Dean and Stark type, but this has a25ml. receiver of special design with a longer scale graduated in 01 ml. and has therefore been omitted from the present standard.SUBSIDIARY STANDARD TEMPERATUREOF 27 C.At the Second Meeting, in 1951, of Technical Committee ISO/TC 48 Laboratory Glassware a
34、nd Related Apparatus, of the International Organization for Standardization, it was agreed to qualify as follows the acceptance of 20 C. as the standard temperature for volumetric glassware :“When it is necessary in tropical countries to work at an ambient temperature considerably above20 C., and th
35、ese countries do not wish to use exclusively the standard temperature of 20 C., it recommended that they should adopt a temperature of 27 C.”In order to meet the requirements of such tropical countries it has been decided to amend the British Standards for volumetric glassware to permit 27 C., as an
36、 alternative to 20 C.In the present British Standard this amendment applies to Clause 7 and to the Figure 5 to Figure 12.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
37、 a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv, pages1 to 18, an inside back cover and a back cover.This standard has been updated (see copyright date) and may have had amendmen
38、ts incorporated. This will be indicated in the amendment table on the inside front cover.BS 756:1952 BSI 03-2000 11 ScopeThis British Standard specifies suitable apparatus for the determination of water by the method of distillation with an immiscible liquid. The method is applicable to a wide range
39、 of materials in industrial processes and laboratory practice.2 Assembly of apparatusThe apparatus shall consist of the following components, assembled as shown in Figure 1 :a) Distillation vessel.b) Condenser, including spray tube if required.c) Receiver.3 MaterialThe receiver and condenser shall b
40、e made of borosilicate glass as free as possible from visible defects, and shall be well annealed.4 Design and dimensionsThe general design and dimensions of the apparatus shall be as shown in Figure 1 to Figure 12. The only mandatory dimensions are those given in Clause 6and Table 2. The remaining
41、dimensions are given for the guidance of manufacturers and are not a mandatory part of the specification, but an apparatus which, on visual inspection, shows any gross departure from them shall be deemed not to comply with the specification.5 Distillation vesselFor different purposes a flask made of
42、 borosilicate glass or a metal flask or pot is suitable. If a glass flask is used, the connection to the receiver shall be made by means of a cork or by a ground glass joint complying with BS 5721), as specified in Table 1. If a metal vessel is used, the connection shall be made by a cork or by othe
43、r suitable means such as that shown in Figure 2.6 Condensera) Design and dimensions. The condenser shall be a glass water-cooled reflux type, of the design and dimensions shown in Figure 3. The only mandatory dimensions (see Clause 4 ) for the condenser are the external diameters of the inner tube a
44、nd of the jacket, which shall be 1617mm. and 2325 mm. respectively.b) Construction. In the construction of the condenser, the following points should be noted: i) The joints A and B should be neatly finished as shown in Figure 3; in particular, the bore at B should have the minimum disturbance.ii) T
45、he shoulder above the cone of the B19 joint at C should be elongated as shown in Figure 3, thus avoiding a sharp re-entrant shape which may restrict the free flow of liquid down the inner wall.iii) The cone should be extended beyond the length appropriate to the B19 joint, and the lower end ground a
46、t an angle of approximately 60 to the axis. The drainage tip should be at the front of the condenser when the lower water-connection is to the left, and the finish should be either smooth or fire-polished.c) Spray tube. The spray tube, if provided, shall be sealed at one end and shall have four smal
47、l holes spaced regularly round its circumference near the closed end; it shall be of the design illustrated in Figure 4.7 Receivera) Type. Two types of receiver are included, as follows: Type 1 is based on the Dean and Stark apparatus proper, and is used with light liquids, such as petroleum spirit
48、or toluole.Type 2 is based on the apparatus specified by the Institute of Petroleum for determining the diluent content of crankcase oil, and is used with heavy liquids such as trichlorethylene or perchlorethylene.b) Sizes. Five sizes of Type1receiver and two sizes of Type 2receiver are specified, a
49、nd are illustrated in, Figure 5 to Figure 12. The connection to the condenser is provided by a ground glass joint of size B19 complying with BS 572 1). Some sizes are provided with stopcocks and with alternative connections to the distillation vessel, as shown in Table 1.1) BS 572, “Interchangeable conical ground glass joints”.BS 756:19522 BSI 03-2000Table 1 Sizes and connections of receivers for dean and stark apparatusTable 2 Mandatory dimensions and tolerances for dean and stark receiversc) Dimensions. The o
