ISO-383-1976.pdf

INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARLXZATION MExWHAPOfiHAl OPrAHW3AUWR IlO CTAHAAPTH3ALWf.ORGANISATION INTERNATIONALE DE NORMALISATION Laboratory glassware - Interchangeable conical ground joints Verrerie de laboratoire - Assemblages coniques rods ? i .: : . ,-%( $ ._ “4.y ; ys: + d ,c ;2 “r.-+ 2 :,-c34 b 6 u- - - .“” _ x t-c i “LA i UDC 542.231.7 Ref. No. IS0 383-1976 (El : 7 Descriptors : laboratory glassware, joints (junctions), conical components, specifications, interchangeability. m % 0 i!? Price based on 5 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 20:03:01 MDTNo reproduction or networking permitted without license from IHS -,-,- FOREWORD IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 Member Bodies). The work of developing International Standards is carried out through IS0 Technical Committees. Every Member Body interested in a subject for which a Technical Committee has been set up has the right to be represented on that Committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the Technical Committees are circulated to the Member Bodies for approval before their acceptance as International Standards by the IS0 Council. Prior to 1972, the results of the work of the Technical Committees were published as IS0 Recommendations; these documents are now in the process of being transformed into International Standards. As part of this process, Technical Committee ISO/TC 48 has reviewed IS0 Recommendation R 383 and found it technically suitable for transformation. International Standard IS0 383 therefore replaces IS0 Recommendation R 383-1964 to which it is technically identical. IS0 Recommendation R 383 was approved by the Member Bodies of the following countries : Australia Austria Belgium Canada Chile Colombia Czechoslovakia France Germany Greece India Israel Japan Netherlands New Zealand Poland Romania Spain Sweden United Kingdom U.S.A. U.S.S.R. The Member Body of the following country expressed disapproval of the Recommendation on technical gorunds : Italy* l Subsequently, this Member Body approved the Recommendation. No Member Body disapproved the transformation of ISO/R 383 into an International Standard. 0 International Organization for Standardization, 1976 l Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 20:03:01 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 383-1976 (E) Laboratory glassware - Interchangeable conical ground joints 0 INTRODUCTION 1 SCOPE AND FIELD OF APPLICATION The purpose of this international Standard is to ensure interchangeability between standard conical ground glass joints, irrespective of where they are manufactured. In order to achieve interchangeability, it is necessary that each of the following requirements be adequately specified, including appropriate tolerances : This International Standard specifies the essential geometric requirements for interchangeability in relation to four series of conical ground glass joints for laboratory use. 2 REFERENCE a) taper; ISO/R 468, Surface roughness. b) large end diameter; c) length of ground zone; d) surface finish. 3 TAPER The taper of the joints shall be such as to give one increment on diameter for ten increments on axial length, with a tolerance of f 0,006 on the diameter increment, i.e. a taper of (I,00 f 0,006)/l 0. The nominal dimensions listed below are based on the series of joints already widely used in many countries; in particular, the series of large end diameters represents the nearest acceptable compromise to the R 40/3 series of preferred numbers (5, 3, . . . . 100) laid down in IS0 3, Preferred numbers - Series of preferred numbers. From the practical point of view, and especially because of the difficulty of carrying out precise measurements on the ground portions of the finished joints, it is desirable to apply a gauging system which allows rapid checking of the essential dimensions. The definition of these dimensions in clause 6 is an integral part of this International Standard, but the system of gauging described in annex A, while it has been proved in practice as fully satisfactory, is not the only one which can be applied for the purpose. The leakage test described in annex B is one which is commonly used for testing joints, but its inclusion in this International Standard is not intended to preclude the use of other tests which may be found more convenient for particular purposes. Attention is specifically drawn to the method of pneumatic gauging. ) NOTE - Actual manufacturing techniques normally result in a tighter tolerance than that given above, but owing to the lack of experimental evidence it is not yet possible to reduce the specified value. , 4 LARGE END DIAMETERS The following series of large end diameters shall be adopted : 5 - 7,5 - 10 - 12,5 - 14.5 - 18,8 - 21,5 - 24 - 29.2 - 34,5-40-45-50-60-71 -85-IOOmm 5 LENGTH OF GROUND ZONE The length of the ground zone I, in millimetres, is calculated using the formula I=k d is the large end diameter, in millimetres. 1) This method is described in Laboratory practice, March 1958, Vol. 7, No. 3, “Pneumatic gauging applied to standard ground glass joints”, by I.C.P. Smith. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 20:03:01 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 383-1976 (El The calculated length is rounded off to the nearest whole number. The four series of joints listed in table 1 are obtained by using the values, 2,4, 6 and 8 for the constant k. k6 is the preferred series. TABLE 1 -Series of joints Dimensions in millimetres 6 TOLERANCES ON DIAMETER AND LENGTH The diameter and length of the ground zone shall be such that, when it is placed with its axis in the plane of the dimensional frame shown in figure 1, it fits in such a way that the upper and lower edges of the ground surface fall within the zones of height ht and h, respectively, the values of d, I, hI and h, for any particular joint size being taken from table 2. For special purposes, the ground surface may extend beyond these limits, provided that the zone of length I is always included within this ground portion. A system of gauging suitable for finding out whether joints fall within these limits is described in annex A. r Large end diameter 12,5 14.5 18.8 21,5 24 29.2 34,5 40 45 50 60 71 85 100 Length of ground zone k6 series k4 series 9 13 11 16 13 19 14 21 15 23 17 26 19 28 20 29 22 32 23 35 38 40 42 46 51 55 60 k2 series k8 series 18 22 25 28 30 35 37 39 43 47 -1 kTwer=G I 1 e (Increase of diameter/length) s” FIGURE I TABLE 2 - Dimensions and tolerances (see clause 6 and figure 1) Dimensions in millimetres k2 series k4 series k6 series k8 series Nominal diameter of joint 5 7.5 10 12,5 14,5 18,s 21,5 24 29.5 34.5 40 45 50 60 71 85 100 d 5,l k 0,008 7.6 i 0,008 10.1 f 0,008 12.6 i 0,010 14.6 F o.010 18.9 + 0,015 21.6 t 0,015 24.1 f 0.015 29,3 i 0,015 34,6 i 0,015 40.1 i 0,015 45,l i 0,015 50,l ?- 0,015 60.1 i 0,015 71.1 i 0,020 85.1 + 0,020 100.1 t 0,020 * Tolerance on = +_ 0,015. * Tolerance on h1 and h2 = i 0,010. 1” h,* h2* 1” h, l * 8 2.5 2 9 2.5 2 10 2.5 2 11 2.5 2 11 2.5 2,5 11 2.5 2.5 12 2.5 2.5 h2* 2 2 2 2 2 2 17 21 24 27 29 34 36 38 40 43 12 15 18 20 22 25 27 28 31 h,* 2 2 2 h2* 2 2 2 hl l * 2.5 2.5 2.5 2.5 2.5 2,5 2,5 2.5 2.5 2.5 h2* 2 2 2 2 2 2 2 2 3,5 3.5 8 10 12 13 14 16 18 19 21 22 2 2 2 2 2 2 2 2 2 2 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 20:03:01 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 383-1976 (E) 7 SURFACE FINISH The centre-line-average height of the ground surface shall not exceed 1 pm and should preferably be less than 0,5 pm. NOTE - The “centre-line-average height” of the ground surface is the average value R, of the roughness as defined in ISO/R 468. 8 DESIGNATION For convenience of reference to joints complying with the geometric requirements of this International Standard, the use is recommended of a designation consisting of the following dimensions, expressed in millimetres : - large end diameter of the joint (7,5 - 12,5 - 14.5 - 18.8 - 21,5 - 29.2 - 34,5 being rounded to 7 - 12 - 14 - 19 - 21 - 29 - 34 respectively), and - length of ground zone, separated by an oblique or horizontal stroke, Example : 19126 or g 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 20:03:01 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 383-1976 (El ANNEX A SUITABLE GAUGING SYSTEM FOR DIAMETER AND LENGTH OF CONICAL JOINTS The suggested gauges are made of hardened steel or other suitable material. The gauges for sockets are conical plugs with a step at each end, and the gauges for cones are conical rings with a step at each end; they are shown in figures 2 and 3. The cone semi-angle of each gauge is 2” 51 45” + 15”. (The sine of the specified angle is 0,049 94 + 0,000 07.) A separate gauge is required for each size of cone or socket, the gauge dimensions being given in table 2. When a socket or cone is fitted to its appropriate gauge, it should rest in such a position that the upper and lower ends of the ground zone lie wholly within the steps of height h, and h, respectively. For special purposes, the ground surface may extend beyond the outer extremity of the step at the smaller end, provided that it also extends to at least the inner extremity of the step at the larger end. FIGURE 2 -Gauge for sockets FIGURE 3 -Gauge for cones Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 20:03:01 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 383-1976 (E) ANNEX B LEAKAGE TEST FOR CONICAL JOINTS The leakage test is carried out on dry joints by observing the rate of increase in pressure in a previously evacuated system in communication with the atmosphere via the leaking joint. A suitable apparatus is used, as illustrated in figure 4, the details not being essential, provided that the total capacity of the system is approximately 1,5 I. It is essential to render all joints in the testing apparatus leak-proof and to check the apparatus before coupling in the joint to be tested. Any leakage found during checking must be negligible in compa- rison with the leakage measured during the test. The degree of cleanliness of the ground surface is a vital factor affecting the rate of leakage. The components are first rubbed with a cloth soaked in a suitable solvent, for example cyclohexane, then dipped in the solvent and allowed to dry. Any particles adhering to the surfaces are removed with a camel s-hair brush. The components are then placed in turn in a vertical position in the apparatus and the system evacuated. No pressure, other than that exerted by the atmosphere, is applied to the joint. When the mercury gauge reading is above 380 mm, the stopcock is closed and after 1 min the scale reading is noted. After a further 5 min, the scale reading is noted again. Having equalized the pressures inside and outside the system, the component is turned on its axis through 90” and the test is then repeated. NOTE - It has been found that when cones and sockets complying with the geometric requirements are tested under the above conditions, the rise in pressure in the system does not exceed 10 mm of mercury over a period of 5 min, the total capacity being 1,5 I. For total capacities differing slightly from 1.5 I, the corresponding maximum pressure rise is in inverse proportion to the capacity. I- Rubber bung F+- Joint under test c Rubber bung or tubing according to size of joint under test Scale covering pressure range of approximately 350 to 760 mmHg in 1 mm increments Mercury U-tube manometer FIGURE 4 -Suitable apparatus for leakage test on conical joints 5 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 20:03:01 MDTNo reproduction or networking permitted without license from IHS -,-,-