ISO 7-2-2000

Reference number ISO 7-2:2000(E) © ISO 2000 INTERNATIONAL STANDARD ISO 7-2 Second edition 2000-09-15 Pipe threads where pressure-tight joints are made on the threads — Part 2: Verification by means of limit gauges Filetages de tuyauterie pour raccordement avec étanchéité dans le filet — Partie 2: Vérification par calibres à limites Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. 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ISO copyright office Case postale 56 � CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.ch Web www.iso.ch Printed in Switzerland ii © ISO 2000 – All rights reserved Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) © ISO 2000 – All rights reserved iii Contents Page Foreword.....................................................................................................................................................................iv Introduction .................................................................................................................................................................v 1 Scope ..............................................................................................................................................................1 2 Normative reference ......................................................................................................................................1 3 Terms and definitions ...................................................................................................................................1 4 Symbols ..........................................................................................................................................................2 5 Design of gauges...........................................................................................................................................3 5.1 General............................................................................................................................................................3 5.2 Taper full form threaded plug gauges (gauges No. 1 and No. 2)..............................................................4 5.3 Parallel full form threaded ring gauge (gauge No. 3) .................................................................................8 5.4 Taper plain ring gauge (gauge No. 4) ........................................................................................................10 5.5 Taper modified thread form check plug gauge (gauge No. 5) ................................................................11 5.6 Parallel modified thread form check ring gauge (gauge No. 6) ..............................................................13 6 Use of gauges and checking of pipe threads ...........................................................................................14 6.1 General..........................................................................................................................................................14 6.2 Checking of internal taper (Rc) and internal parallel (Rp) threads.........................................................15 6.3 Checking of external taper (R) threads .....................................................................................................16 7 Gauge dimensions and manufacturing tolerances, checking of new gauges and checking gauges for wear ...........................................................................................................................................17 7.1 Gauge dimensions and manufacturing tolerances..................................................................................17 7.2 Checking of new gauges.............................................................................................................................23 7.3 Checking gauges for wear ..........................................................................................................................26 7.4 Marking of gauges .......................................................................................................................................28 Annex A (normative) Summary of gauges..............................................................................................................29 Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) iv © ISO 2000 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established 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. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 7 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 7-2 was prepared by Technical Committee ISO/TC 5, Ferrous metal pipes and metallic fittings, Subcommittee SC 5, Threaded or plain end butt-welding fittings, gauging of threads. This second edition cancels and replaces the first edition (ISO 7-2:1982), which has been technically revised. ISO 7 consists of the following parts, under the general title Pipe threads where pressure-tight joints are made on the threads: � Part 1: Dimensions, tolerances and designation � Part 2: Verification by means of limit gauges Annex A forms a normative part of this part of ISO 7. Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) © ISO 2000 – All rights reserved v Introduction This revision of ISO 7-2 has been undertaken with the aim of providing a unified gauging system which could be adopted worldwide and thus eliminate the differing gauging results obtained with the use of gauges in accordance with ISO 7-2:1982 and existing national practices. This revision also includes details of plain ring gauges to provide additional means of checking ISO 7-1 external threads and a parallel modified thread form check ring gauge for checking taper full form threaded plug gauges. Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service INTERNATIONAL STANDARD ISO 7-2:2000(E) © ISO 2000 – All rights reserved 1 Pipe threads where pressure-tight joints are made on the threads — Part 2: Verification by means of limit gauges 1 Scope This part of ISO 7 specifies a process using limit gauges, for the validation of taper internal and external threads and parallel internal threads on piping systems components and other products, the dimensions and tolerances of which are detailed in ISO 7-1. The gauging system described may not be suitable, without special precautions, for gauging of threads on injection moulded plastic workpieces. This part of ISO 7 does not cover completely all the requirements necessary for full control of thread quality and dimensions. Additional control of tools and equipment and visual inspection during production are required to ensure complete compliance with ISO 7-1, for example the length of useful thread on internally threaded workpieces should be checked by direct measurement. Annex A gives a summary of the gauges included in this part of ISO 7, together with details of the thread elements controlled by each gauge and gauge identification numbers. In the event of a dispute over compliance with the requirements of ISO 7-1, the gauges in this part of ISO 7 are to be considered as decisive for the thread elements which they control on the workpiece. 2 Normative reference The following normative document contains provisions which, through reference in this text, constitute provisions of this part of ISO 7. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of ISO 7 are encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 7-1:1994, Pipe threads where pressure-tight joints are made on the threads — Part 1: Dimensions, tolerances and designation. 3 Terms and definitions For the purposes of this part of ISO 7, the terms and definitions given in ISO 7-1 and the following apply. 3.1 accommodation length distance from the face of an internally threaded workpiece to the first obstruction which the externally threaded workpiece will encounter on assembly See Figure 3. Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) 2 © ISO 2000 – All rights reserved 4 Symbols The symbols used and their explanations are given in Table 1. Table 1 — Symbols Symbol Explanation b1 Width of clearance groove at major diameter of parallel full form threaded ring gauges and minor diameter of taper full form threaded plug gauges b2 Width of clearance groove at major diameter of parallel modified thread form check ring gauges and at minor diameter of taper modified thread form check plug gauges c Height of tolerance step on plug gauges D Major diameter of internal thread at gauge plane D1 Minor diameter of internal thread at gauge plane D2 Pitch diameter of internal thread at gauge plane D4 Counterbore diameter of parallel full form threaded ring gauge and taper plain ring gauge d Major diameter of external thread at gauge plane d1 Minor diameter of external thread at gauge plane d2 Pitch diameter of external thread at gauge plane F Radial distance from the pitch diameter to the truncated crest, along the centreline of the thread profile l0 Overall length of taper full form threaded plug gauge and taper modified thread form check plug gauge l1 Length from end face to the gauge plane on taper full form threaded plug gauge l2 Length of tolerance step on plug gauges l3 Overall length of parallel full form threaded ring gauge, parallel modified thread form check ring gauge and length from gauge plane to small end of taper plain ring gauge l4 Length of tolerance step on ring gauges l5 Depth of counterbore on parallel full form threaded ring gauge l6 Overall length of taper full form threaded plug gauge with relief l7 Width of relief on taper full form threaded plug gauge with relief l8 Length from relief on taper full form threaded plug gauge with relief to large end of gauge l9 Overall length of taper plain ring gauge l10 Depth of counterbore on taper plain ring gauge l11 Distance from step on gauge Nos. 1 and 2 to face of gauge No. 6 when verifying pitch diameter of new gauge Nos. 1 and 2 l12 Distance from step on gauge No. 5 to face of gauge No. 6 when verifying pitch diameter of new gauge No. 6 l13 Distance from step on gauge Nos. 1 and 2 to face of gauge No. 6 when checking pitch diameter of gauge Nos. 1 and 2 for wear Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) © ISO 2000 – All rights reserved 3 Table 1 (concluded) Symbol Explanation l14 Distance from step on gauge No. 5 to face of gauge No. 3 when checking pitch diameter of gauge No. 3 for wear P Pitch T� 1/2 Tolerance on flank angle of full form threads T� 2/2 Tolerance on flank angle of modified form threads TCP Tolerance on pitch diameter for taper modified thread form check plug gauge and parallel modified thread form check ring gauge TP Tolerance on pitch TPL Tolerance on pitch diameter and wear allowance for taper full form threaded plug gauges TR Tolerance on pitch diameter and wear allowance for parallel full form threaded ring gauge and tolerance on diameter and wear allowance for taper plain ring gauge T1 Tolerance on the gauge length of an external thread T2 Tolerance on position of gauge plane on an internal thread W Permissible wear on diameter of all gauges except taper modified thread form check plug gauges NOTE The values of D, D1, D2, d, d1 and d2 shown in Table 2 to Table 7 are basic values and are subject to the manufacturing tolerances specified in clause 7. 5 Design of gauges 5.1 General The taper full form threaded plug gauges and parallel full form threaded ring gauges (see 5.2 and 5.3) together with the taper plain ring gauges (see 5.4) have been chosen as representing the requirements for mating components or products within the tolerances of ISO 7-1. Because of the 1:16 taper of the gauge and/or the threaded workpiece, it is possible to represent the maximum and minimum limits of diameter by means of tolerance steps within the axial length of the gauges. The plain ring gauges included in this part of ISO 7, allow a combined check of the major diameter and the length of useful thread of externally threaded workpieces. The taper modified thread form check plug gauge (see 5.5) and parallel modified thread form check ring gauge (see 5.6) for checking the manufacturing tolerances and wear allowances for the parallel full form threaded ring gauges and taper full form threaded plug gauges respectively, are made to a modified thread form. Some dimensions given in this part of ISO 7 are more precise than the equivalent dimensions given in ISO 7-1. This greater precision is only intended to assist the gauge manufacturing process and is of no practical significance when using the gauges. NOTE The expression "full form" has been used to describe those threaded plug and ring gauges which may be full form or alternatively have thread form relief at the discretion of the manufacturer, so as to differentiate from those threaded check plug and check ring gauges which are always of modified thread form. Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) 4 © ISO 2000 – All rights reserved 5.2 Taper full form threaded plug gauges (gauges No. 1 and No. 2) 5.2.1 Taper full form threaded plug gauge (gauge No. 1) This gauge is a 1:16 taper full form threaded plug gauge (see Figure 1) and is suitable for checking the major diameter (D) and pitch diameter (D2) at the gauge plane of internal parallel (Rp) threads and internal taper (Rc) threads. Figure 1 — Taper full form threaded plug gauge (gauge No. 1) The dimensions of this gauge are given in Table 2 and manufacturing tolerances are given in 7.1.1.2. The gauge incorporates a step equal in length to the total tolerance T2 on the position of the gauge plane of the internal thread specified in ISO 7-1. To allow for the chamfer on the internal thread, the step is displaced by 0,5P relative to the gauge plane, such that the internally threaded workpiece can be verified with reference to its face. The large diameter end face of the gauge is marked '+' (positive) and the face of the tolerance step is marked '–' (negative). NOTE For sizes smaller than 1/2, the '+' and '–' markings may be omitted if not practicable. Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) © ISO 2000 – All rights reserved 5 Table 2 — Dimensions of taper full form threaded plug gauge (gauge No. 1) Dimensions in millimetres Diameters at gauge plane Designation of thread Pitch major Pitch minor Overall length of gauge Length from end face to the gauge plane Length of tolerance step Width of clearance groove Height of step P d, D d2, D2 d1, D1 l0 l1 l2 b1 max. c 1 2 3 4 5 6 7 8 9 10 1/16 0,907 7,723 7,142 6,561 5,6 1,588 2,268 0,3 1,8 1/8 0,907 9,728 9,147 8,566 5,6 1,588 2,268 0,3 1,8 1/4 1,337 13,157 12,301 11,445 8,4 2,339 3,342 0,4 2,4 3/8 1,337 16,662 15,806 14,950 8,8 2,339 3,342 0,4 2,4 1/2 1,814 20,955 19,793 18,631 11,4 3,175 4,536 0,5 3,3 3/4 1,814 26,441 25,279 24,117 12,7 3,175 4,536 0,5 4,5 1 2,309 33,249 31,770 30,291 14,5 4,041 5,773 0,6 5,8 1 1/4 2,309 41,910 40,431 38,952 14,5 4,041 5,773 0,6 5,8 1 1/2 2,309 47,803 46,324 44,845 14,5 4,041 5,773 0,6 5,8 2 2,309 59,614 58,135 56,656 15 4,041 5,773 0,6 5,8 2 1/2 2,309 75,184 73,705 72,226 17,5 4,618 6,927 0,6 6,9 3 2,309 87,884 86,405 84,926 18,5 4,618 6,927 0,6 6,9 4 2,309 113,030 111,551 110,072 20 4,618 6,927 0,6 6,9 5 2,309 138,430 136,951 135,472 24 4,618 6,927 0,6 10 6 2,309 163,830 162,351 160,872 24 4,618 6,927 0,6 10 NOTE The values given in columns 3, 4 and 5 are basic values intended for the calculation of diameters at the gauge plane in accordance with 7.1.1. 5.2.2 Taper full form threaded plug gauge with relief (gauge No. 2) This gauge is a 1:16 taper full form threaded plug gauge with relief of threads (see Figure 2) and is suitable for checking the major diameter (D) and pitch diameter (D2) at the gauge plane, and the accommodation length (see Figure 3) of internal parallel (Rp) threads and internal taper (Rc) threads. Als Papierkopie - kein Änderungsdienst / Printed copy - no alert service ISO 7-2:2000(E) 6 © ISO 2000 – All rights reserved Figure 2 — Taper full form threaded plug gauge with relief (gauge No. 2) NOTE Figure 3 is applicable to internal parallel (Rp) threads and internal taper (Rc) threads. Figure 3 — Accommodation length The dimensions of this gauge are given in Table 3 and manufacturing tolerances are given in 7.1.1.2. The gauge incorporates a step equal in length to the total tolerance T2 on the position of the gauge plane of the internal thread specified in ISO 7-1. To allow for the chamfer on the internal thread, the step is displaced by 0,5P relative to the gauge plane, such that the internally threaded workpiece can be checked with reference to its face. On sizes 1/4 and larger, a thread relief is provided part way along the gauge, thereby reducing the number of threads and consequential friction in contact with the internally threaded workpiece. The overall length (l6) of the gauge is equal to the length of useful thread fo