1、 Intentionally left blank AN AMERICAN NATIONAL STANDARD Hose Coupling Screw Threads (Inch) ASME BI .20.7-1991 (REVISION OF ANSVASME B1.20.7-1966) The American Society of Mechanical Engineers _ 345 East 47th Street, New York, N.Y. 1001 7 - Date of Issuance: April 16, 1992 This Standard will be revise
2、d when the Society approves the issuance of a new edition. There will be no addenda or written interpretations of the re- quirements of this Standard issued to this edition. ASME is the registered trademark of The American Society of Mechanical Engineers This code or standard was developed under pro
3、cedures accredited as meeting the criteria for American National Standards. The Consensus Committee that approved the code or standard was balanced to assure that individuals from competent and concerned interests have had an opportunity to participate. The proposed code or standard was made availab
4、le for public review and comment which provides an opportunity for additional public input from industry, academia, regulatory agencies, and the public-at-large. ASME does not “approve,“ “rate,“ or “endorse“ any item, construction, proprietary device, or activity. ASME does not take any position wit
5、h respect to the validity of any patent rights asserted in connection with any items mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability for infringement of any applicable Letters Patent, nor assume any such liability. Users of a code or standar
6、d are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, is entirely their own responsibility. Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted as government or i
7、ndustry endorsement of this code or standard. ASME accepts responsibility for only those interpretations issued in accordance with governing ASME procedures and policies which preclude the issuance of interpretations by individual volunteers. No part of this document may be reproduced in any form, i
8、n an electronic retrieval system or otherwise, without the prior written permission of the publisher. Copyright 0 1992 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U.S.A. (This Foreword is not part of ASME B1.20.7-1991.) Local standards for small hose coupling threa
9、ds in use prior to 1920 were summarized in a table in the Proceedings of the National Fire Protection Association, Vol. 24, 1920, p. 180. Of these, the Standard Iron Pipe Thread had been most widely used, and it had been reliably reported that this thread had been in use for small hose couplings sin
10、ce 1894 or earlier. In the case of the three-fourths-inch size, however, 11 and 11% threads per inch, with a diameter of 1%6 in. were already in very extensive use for garden hose. It was reported that the first garden hose spray nozzle had been made prior to 1890 in the shops of the W. D. Allen Mfg
11、. Co., Chicago. In 1918 the Fire Dept. Supply and Linen Hose Section of the War Industries Board rec- ommended that for the duration of the war “hydrants, hose valves, hose couplings, nipples, and nozzles 1% in. to 2 in., inclusive, to be iron pipe thread for new work, hose gauge or special threads
12、only to be used for replacement or extension of existing plant equipment. The adoption of such a standard will result in the elimination of the various so-called hose threads which are used locally in the different sections of the country. Such a standard will also permit repairs or connections bein
13、g made in the field by the use of wrought iron pipe connections or fittings. It will also result in considerable saving in correspondence and detail now necessary in endeavoring to ascertain what particular hose standard thread is desired.” A blueprint of the nominal sizes and pitches of hose thread
14、 dimensions, dated March 5, 1918, of the National Association of Brass Manufacturers was furnished the National Screw Thread Commission in November, 1918. Limits of size for iron pipe thread sizes and pitches were designed as National hose coupling thread dimensions and adopted by the National As- s
15、ociation of Brass Manufacturers March 18, 1920. These were in agreement with those in the Progress Report of the N.S.T.C., approved June 19, 1920, and published January 4, 1921 as NBS Miscellaneous Publication No. 42. A survey in 1925 of some of the members of the National Association of Brass Manuf
16、acturers showed these standards to be satisfactory. These threads from /2 to 2 in. diameter are now designated “NPSH. ” In January 1927, The American Society of Mechanical Engineers requested the American Engineering Standards Committee (later changed to the American Standards Association) to author
17、ize the organization of a Sectional Committee to complete the standardization of firehose couplings and to attempt to unify and complete the existing dimensions of small hose cou- plings. This authority was given and the Sectional Committee B33 was organized in October, 1928, under the sponsorship o
18、f The American Society of Mechanical Engineers, to prepare specifications for screw threads for small hose couplings ranging from I/z to 2 in. nominal size. A draft dated July 1935 was approved by the American Standards Association and issued as At its meeting of April 13, 1961, the ASA Mechanical S
19、tandards Board assigned respon- ASA B33.1-1935. sibility for future revisions of the American Standards B26-1925, Fire-Hose Couplings Screw Thread, and B33.1-1935, Hose Coupling Screw Threads to Sectional Committee B2. As a result, the name of the Committee was changed to Sectional Committee B2 on t
20、he Standardization of Pipe and Hose Coupling Threads. 111 . Subcommittee 6 on Hose Coupling Threads was organized and held its first meeting on October 24, 1962 to undertake the revision of ASA B33.1-1935. Subcommittee 7 on Fire Hose Coupling Threads was organized and held its first meeting on Octob
21、er 25, 1962 to undertake the revision of ASA B26-1925. It was arranged that Sub- committee 7 would include in its scope those thread sizes in ASA B33.1-1935 which are used primarily for fire protection purposes. The proposed revision of B33.1, designated B2.4, was submitted to the sponsor organiza-
22、tions and the United States of America Standards Institute, and formally designated a USA Standard on December 30, 1966. In 1973 the American National Standards Committee B2 was absorbed by ANSI Standard Committee B1 and reorganized as Subcommittee 20. B2.4 was reaffirmed without revision by Standar
23、d Committee B1 and redesignated as ANWASME Standard B1.20.7 on August 5, 1983. This revision was approved by the American National Standards Institute on September 19, 1991. iv ASME STANDARDS COMMITTEE B1 Standardization and Unification of Screw Threads (The following is the roster of the Committee
24、at the time of approval of this Standard.) OFFICERS E. Schwartz, Chairman K. E. McCullough, Vice Chairman R. McGinnis, Secretary COMMITTEE PERSONNEL A. R. Breed R. J. Browning R. M. Byrne D. P. Cadieux F. H. Cantrell R. S. Chamerda R. Dodge P. J. Drake A. E. Ellis H. W. Ellison C. G. Erickson W. C.
25、Farrell. Jr. G. A. Flannery D. S. George J. 0. Heinze C. W. Jatho S. P. Johnson S. I. Kanter R. W. Lamport R. S. LaNier J. B. Levy K. E. McCullough J. L. McMurray W. R. Newman A. Painter G. A. Russ R. J. Sabatos D. M. Satava M. M. Schuster E. Schwartz R. Searr R. Seppey A. D. Shepherd, Jr. V. B. Sho
26、ok A. G. Strang J. F. Sullivan R. L. Tennis A. F. Thibodeau J. Trilling C. J. Wilson SUBCOMMITTEE 91.20 - PIPE THREADS 0. P. Cadieux, Chairman A. F. Thibodeau, Secretary C. F. Banks D. Berg M. J. Bibeau P. F. Braun R. J. Browning F. G. Calderone J. A. Casner W. 0. Clinedinst F. Dallas, Jr. L. N. Dix
27、on, Jr. R. Dodge W. C. Farrell, Jr. L. S. Feldheim G. A. Flannery S. Jiles S. I. Kanter R. P. Knittel M. W. Rose G. A. Russ D. M. Satava A. D. Shepherd, Jr. A. G. Strang A. M. Wilkerson V Intentionally left blank CONTENTS . Foreword . 111 Standards Committee Roster. . v 1 Scope 1 1.1 Purpose . 1 1.2
28、 Federal Government Use 1 1.3 Reference Documents. 1 2 Thread Designations. 1 3 Tolerances 1 3.1 For Nipple (External) Threads. . 2 3.2 For Coupling Swivel (Internal) Threads 2 4 Acceptability 2 Figure 1 Thread Form for American National Standard Hose Coupling Threads, NPSH,NH,andNHR 3 Tables 1 Desi
29、gn Dimensions of American National Standard Hose Coupling Threads,NPSH,NH,andNHR 4 2 Product External Thread Limits of Size and Tolerances for American National Standard Hose Coupling Threads, NPSH, NH, and NHR Nipples 5 3 Product Internal Thread Limits of Size and Tolerances for American National S
30、tandard Hose Coupling Threads, NPSH, NH, and NHR Coupling Swivels 6 Threads,NPSH,NH,andNHR 7 Diameter Tolerances for American National Standard Hose Coupling Threads,NPSH,NH,andNHR 8 6 Gage Limits of Size of Ring Gages for External (Nipple) Threads for American National Standard Hose Coupling Thread
31、s, NPSH, NH, andNHR . 9 Threads for American National Standard Hose Coupling Threads NPSH,NH,andNHR 10 Standard Hose Coupling Threads, NPSH, NH, and NHR . 11 4 Lengths of Threads for American National Standard Hose Coupling 5 Variations in Lead and Half-Angle Consuming One-Half of Pitch 7 Gage Limit
32、s of Size of Plug Gages for Internal (Coupling Swivel) 8 Setting Plug Gage Limits of Size for Ring Gages for American National vii Appendix A American National Fire-Hose Coupling Threads . 13 A1 Scope . 13 Tables AI Basic Dimensions of American National Fire-Hose Coupling Threads. A2 Thread Limits o
33、f Size and Tolerance for NH Internal Thread NH 13 (Couplings) . 14 A3 Limits of Size and Tolerances of NH External Threads (Nipples) . 14 viii ASME B1.20.7-1991 HOSE COUPLING SCREW THREADS 1 SCOPE 1.1 Purpose The purpose of this document is to provide standards for application to the threaded parts
34、of hose couplings, valves, nozzles, and all other fittings used in direct con- nection with hose intended for domestic, industrial, and general service in nominal sizes of V2, Vs, 3/4, 1, 1 V4, 1%, 2, 2%, 3, 3%, and 4 in. The normal sequence of connections, in relation to the direction of flow, is f
35、rom an externally threaded nip- ple into an internally threaded coupling. The basic dimensions are given in Table 1 while com- plete detailed dimensions and thread form are given in Tables 2 and 3. 1.2 Federal Government Use When this Standard is approved by the Department of Defense and Federal Age
36、ncies and is incorporated into FED-STD-H28/ 10, Screw Thread Standards for Federal Services Section 10, the use of this Standard by the Fed- eral Government is subject to all the requirements and limitations of FED-STD-H28/10. 1.3 Reference Documents The latest issues of the following documents form
37、 a part of this Standard to the extent specified herein: ANWASME B1.7M Nomenclature, Definitions, and Letter Symbols for Screw Threads ANSUASME B1.3M Screw Thread Gaging Sys- tems for Dimensional Ac- ceptability ANSIIASME B1.2 Gages and Gaging for Uni- fied Inch Screw Threads ASME/ANSI B47.1 Gage Bl
38、anks 2 THREAD DESIGNATIONS Threads are designated NH, NHR, and NPSH. The significance of each designation is as follows: NH Standard hose coupling threads of full form and fire hose. NHR Standard hose coupling threads for garden hose application where the design utilizes thin walled material which i
39、s formed to the desired thread. NPSH Hose coupling joints ordinarily made with straight internal and external loose-fitting threads. By the use of this thread series, it is possible to join small hose couplings in sizes 12 to 4; inclusive, to ends of standard pipe having NPT threads using a gasket t
40、o seal the joint. 3 TOLERANCES, Figure 1 shows the relationship between external (nipple) and internal (coupling swivel) dimensions. The pitch diameter tolerances for a mating nipple and coupling swivel are the same. Pitch diameter tolerances include lead and angle variations. Values for variations
41、in lead and half-angles consuming one-half of the pitch diameter tolerance are shown in Table 5. The tolerance relationships are as follows. 1 ASME B1.20.7-1991 HOSE COUPLING SCREW THREADS (INCH) 3.1 For Nipple (External) Threads (except NHRI (a) Major Diameter Tolerances = 2 X Pitch Diam- eter Tole
42、rance (b) Minor Diameter Tolerance = Pitch Diameter Tolerance + 2h/9 (h = Basic Thread Height. See Fig. 1). The minimum minor diameter of the nipple is such as to result in a flat equal to 13 of the P/8 basic flat or P/24 at the root, when the pitch diameter of the nipple is at its minimum value. Th
43、e maximum minor diameter is such as to result in a P/8 flat at the root of the nipple thread at maximum pitch diameter, but may be such as what would be produced by the use of a worn or rounded threading tool. This is the maximum minor diameter shown in Fig. 1 and is the diameter on which the minor
44、diameter tolerance formula shown above is based. In practice, the minor diameter of an external thread is sat- isfactory when accepted by a gage or gaging method that represents the maximum material condition of the internal thread. 3.2 For Coupling Swivel (Internal) Threads (except NHRI (a) Minor D
45、iameter Tolerance = 2 X Pitch Diame- ter Tolerance. The minimum minor diameter of the cou- pling swivel is such as to result in a basic flat of PI8 at the crest when the pitch diameter of the coupling swivel is at its minimum value. (b) Major Diameter Tolerance = Pitch Diameter Tolerance + 2h/9. The
46、 minimum major diameter of the coupling swivel is such as to result in a basic flat of P/8 at the root of the thread when the pitch diameter is at its minimum value. 4 ACCEPTABILITY Acceptability of product screw threads, based on the method specified, shall be in accordance with ANSI/ ASME B1.3M. G
47、ages and gaging are in accordance with ANSI/ASME B1.2. Gage dimensions are specified in Tables 6, 7, and 8. The maximum minor diameter of the GO thread gage for external product threads is equal to the minimum minor diameter of the internal product thread. All other gage dimensions are calculated in
48、 ac- cordance with ANSUASME B1.2. Gage design shall be in accordance with American National Standard ASME/ ANSI B47.1. 2 HOSE COUPLING SCREW THREADS /INCH) ASME 61.20.7-1 991 P h (Heavy line shows basic size) FIG. 1 THREAD FORM FOR AMERICAN NATIONAL STANDARD HOSE COUPLING THREADS, NPSH, NH, AND NHR
49、3 ASME B1.20.7-1991 HOSE COUPLING SCREW THREADS (INCH) TABLE 1 DESIGN DIMENSIONS OF AMERICAN NATIONAL STANDARD HOSE COUPLING THREADS, NPSH, NH, AND NHR Nominal Size of Hose 1 , 5/ , 112 , 518 , 314 12 314 1 1 114 1 112 2 2 112 3 3 12 4 4 Note (1 )I Per tpi Designation Service Inch, I Thread I 2 11.5 11.5 14 14 11.5 11.5 11.5 11.5 8 8 8 6 8 - 3 4 3/4-1 1.5NH Garden hose 3/4-1 1.5NHR Garden hose formed thread 12- 14NPSH 3/4-14NPSH Steam, air, 1-1 1.5NPSH water, and lV-11.5NPSH all other hose 1 12- 1
