Asme b1 20 3 1976 (2003)

DryseaI PipeThreads (Inch) ANSI B1.20.3 - 1976 ( R E V I S I O N A N D R E D E S I G N A T I O N OF 82.2-1968) REAFFIRMED2003 1998 REAFFIRMED FOR CURRENTCOMMITTEE COMMllTEE PERSONNEL PERSONNEL FOR CURRENT PLEASE SEE ASME MANUALAS-I PLEASE E-MAIL CS@asme.org SECRETARIAT SOCIETY OF AUTOMOTIVE ENGINEERS THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS P U B L I S H E D BY T H EA M E R I C A NS O C I E T Y United Engineering Center OF M E C H A N I C A LE N G I N E E R S E a s t t h Street New York, N Y 1001 Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh A M E R I C AN NA T I O N AS LT A N D A R D ACCEPTANCE NOTICE The above non-Government document was adopted(withexceptionlistedbelow)on311980and i s approved forusebytheFederalagencies The i n d i c a t e di n d u s t r yg r o u p has furnishedtheClearancerequired by e x f s t i n gr e g u l a t i o n s C o p i e so ft h e document arestocked by the 000 S i n g l e Stock Point,NavalPublications and Forms Center,Philadelphia, PA 19120, f o ri s s u et o DoD a c t i v i t i e so n l y C o n t r a c t o r s and i n d u s t r y groups must o b t a i n c o p i e s d i r e c t l y from: The American SocietyofMechanicalEngineers UnitedEngineeringCenter, 345 East47thStreet, New York NY 10017 o r The American N a t i o n a lS t a n d a r d sI n s t i t u t e , 1430 Broadway, New York NY 10018 T i t l e o f Document: DrysealPipeThreads(Inch) DateofSpecificIssue ReleasingIndustry Exception: Adopted: Group: 18 November 1976 The American SocietyofMechanicalEngineers - The FederalagenciesuseofthisStandard of FED-STD-H28/8 Screw-ThreadStandards Military Custodians: Army AR Navy AS Air Force - 11 - Review A c t i v i t i e s : Army - AT, AV, ER, ME, M I Navy OS, SH YD - i s s u b j e c tt oa l lt h er e q u i r e m e n t s and l i m i t a t i o n s f o r FederalServicesSection 8, DrysealPipeThreads c i v i l Agency C o o r d i n a t i n g A c t i v i t i e s : Comnerce - NBS DOT - ACO, FHW FIS FRA, ROS GSA - FSS PCD HUO - TCS I n t e r i o r - 8PA Justice - FPI NASA - JFK, LRC, MSF USOA AFS - Military Coordinating Activity: OLA- I S ( P r o j e c t THCS-0034) NOTICE: When r e a f f i r m a t i o n amendment, r e v i s i o n ,o rc a n c e l l a t i o no ft h i ss t a n d a r di si n i t i a l l y t h ei n d u s t r yg r o u pr e s p o n s i b l ef o rt h i ss t a n d a r ds h a l li n f o r mt h em i l i t a r yc o o r d i n a t i n ga c t i v i t yo ft h e proposedchangeandrequest their participation proposed, AREA THOS No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher Copyright 1977 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All Rights Reserved Printed in U S A Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh ANSI 81.20.3-1976 31 October 1980 In 1913 a Committee on the Standardization of Pipe Threads was organized for the purpose of reediting and expanding the Briggs Standard The American Gas Association and The American Society of MechanicalEngineersservedasjointsponsors.Aftersixyearsofwork,thiscommitteecompletedthe revised standardfortaperpipethreadwhichwaspublished in the ASME “Transactions”of 1919, and wasapprovedasanAmericanStandardbythethenAmericanEngineeringStandardsCommittee(later changed to American Standards Association) in December, 1919 It was the first standard to receive this designation under the ASA procedure, and was later republished in pamphlet form In the years which followed, the need for a further revision of this American Standard becameevident as well as the necessity of adding to it the recent developments in pipe threading practice Accordingly, the Sectional Committee on the Standardization of Pipe Threads, B2, was organized in 1927 under the joint sponsorship of the A.G.A and the ASME During the following 15 years, several meetings were held leading t o approval by the members of the Sectional Committee, of the April 1941 draft The revision was approved by the sponsors and ASA and published as an American Standard in October 1942 Shortly after publication of the 1942 standard, the Committee undertook preparation of a complete revision The text and tables were re-arranged and expanded to include Dryseal pipe threads, and an extensive appendix was added to provide additional data on the application of pipe threads and to record in abbreviated form the several special methods which were established for gaging some of the various applications of pipe threads TheresultingproposalwasdesignatedanAmericanStandard on December 1 , 1945 The section covering Dryseal Pipe Threads in ASA B2.1-1945 was deleted and developed as a separate standard designated ASA B2.2-1960, Dryseal Pipe Threads Another updating occurred with republication as USAS B2.21968 In 1973, Standards Committee B2 was absorbed by American National Standards Institute Standard Committee B1 and reorganized as subcommittee 20 A complete rewrite of the B2.2-1968 document was undertaken with the product thread data in separate documents from the gaging standards for Dryseal Pipe threads The system of renumbering, to include metric revisions, is as follows: ANSI B1.20.3-1976 Inch Dryseal Pipe Threads ANSI B1.20.4-1976 Metric Dryseal Pipe Threads ANSI B1.20.5-197 Gaging for Inch Dryseal Pipe Threads ANSI B1.20.6-197 Gaging for Metric Dryseal Pipe Threads Since the product thread documents are being published before completion of the new gaging standards, the ,gaging data in the B2.2-1968 Standard should be used until superseded by publication of the new B 1.20.5 and B 1.20.6gaging standards ANSI B 1.20.3 and B 1.20.4 were approved by ANSI Committee B for publication as official ANSI Standards and thereupon submitted to the Secretariat and the American National Standards Institute They were approved and formally designated as American National Standards on November 18, 1976 iii Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh FOREWORD (The following is the roster of the Committee at the time of approval of this standard) Organized Reorganized June, 1921 February, 1929 SPONSORS: Society of Automotive Engineers The American Society of Mechanical Engineers SCOPE: Nomenclature of screw threads; formof threads; diameter and pitches of screws for various uses; classification of thread fits, tolerances and allowances for threaded parts; and the gaging of threads Screw threads for fire hose couplings are not included within the scope T C Baumgartner, Chairman J B Levy, Vice-chairman S W Taylor, Secretary AEROSPACE INDUSTRIES ASSOCIATION O F AMERICA, INC Propulsion Technical Committee D H Secord, Pratt & Whitney Aircraft, E Hartford, Connecticut National Aerospace Standards Committee E L Wall, McDonell Aircraft Company, St Louis, Missouri AIRCRAFT LOCKNUT MANUFACTURERS ASSOCIATION Charles Fineran, ESNA Division, American Amerace Corporation, Union, N.J AIR INDUSTRIES CORPORATION Edward Clark, Air Industries Corporation, Garden Grove, California Alex Butovich, Alternate, Air Industries Corporation, Garden Grove, California AMERICAN MEASURING TOOL MANUFACTURERS ASSOCIATION Dale Dodge, Pennoyer-Dodge Company, Glendale, California AMERICAN SOCIETY OF MECHANICAL ENGINEERS, THE Edward McHugh, Professor, Clarkson CoUege of Technology, Potsdam, New York ANTIFRICTION BEARING MANUFACTURERS ASSOCIATION William J Derner, Bearing Division, FMC Corporation, Indianapolis, Indiana ASSOCIATION O F AMERICAN RAILROADS Engineering Division C C Herrick, New York Central System, New York, New York BELOIT TOOL CORPORATION Phillip V Pasrore, Beloit Tool Corpwation, South Beloit, Illinois J Heinze, Alternate, Beloit Tool Corporation, South Beloit, Illinois BENDIX CORPORATION, THE Dale Story, The Bendix Corporation, South Beloit, Illinois CLARK EQUIPMENT COMPANY N Badgley Clark Equipment Company, Battle Creek, Michigan V Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh AMERICAN NATIONAL STANDARDSCOMMITTEE 61 Standardization and Unification of Screw Threads COMPRESSED GAS ASSOCIATION INC M E Steczynski, Steczynski & Associates, Chicago, Illinois E A Olsen, Alternate, Compressed Gas Associate lnc., New York, New York DEFENSE INDUSTRIAL SUPPLY CENTER Eli Schwartz, Defense Industrial Supply Center Philadelphia, Pennsylvania Francis S Ciccarone, Alternate, Defense Industrial Supply Center, Philadelphla Pennsylvania FARM & INDUSTRIAL EQUIPMENT INSTITUTE C W Stockwell (observed, International Harvester Co., Hinsdale Illinois FORD MOTOR COMPANY S E Mallen, Ford Motor Company Dearborn, Michigan J F Nagy, Alternate, Ford Motor Company, Dearborn Michigan GEOMETRIC TOOL CORPORATION E S Zook, Geometric Tool, New Haven, Connecticut GREENFIELD TAP & DIE DIVISION O F TRW INC D J Ernanuelli, Greenfield Tape & Die, A United-Greenfield Divislon of TRW Inc., Greenfield, Massachusetts HANSON-WHITNEY COMPANY, THE S Kanter, The Hanson-Whitney Company, Hartford, Connecticut HI-SHEAR CORPORATION M M Schuster, Hi-Shear Corporation, Torrance, California INDUSTRIAL FASTENERS INSTITUTE T C Baumgartner, Chairman, Standard Pressed Steel Company, Jenkintown, Pennsylvania R Belford, Industrial Fasteners Institute Cleveland, Ohio R M Harris, Alternate, Bethlehem Steel Company, Lebanon, Pennsylvania D Wheeler, Armco Steel Corporation, Kansas City, Missouri R W Grower, Bethlehem Steel Company, Lebanon, Pennsylvania K E McCullough, Alternate, Standard Pressed Steel Company, Jenkintown, Pennsylvania J C McMurray, Russell,Burdsall & Ward Bolt & Nut Company Port Chester, New York JOHNSON GAGE COMPANY, THE R S Chamerda, The Johnson Gage Co., Bloomfield, Connecticut Stanley Johnson, Alternate, The Johnson Gage Co., Bloomfield, Connecticut MANUFACTURERS STANDARDIZATION SOCIETY OF THE VALVE & FITTINGS INDUSTRY J R Welshman, Grinnel Corp., Providence, Rhode Island METAL CUTTING TOOL INSTITIJTE Tap and Die Division C G Erickson, Pratt & Whitney Small Tool Division, Colt Industries, Inc., W Hartford, Connecticut NATIONAL AUTOMATIC SPRINKLER & FIRE CONTROL ASSOCIATION Frank Hills, ColIigan Fyr-Protexion, Indianapolis, Indiana Ray Malek, Paul J Gruneau Company, Milwaukee, Wisconsin NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION F V Kupchak, Westinghouse Electric Corporation, Pittsburgh Pennsylvania J B Levy,Vice-Chairman, General Electric Company, Schenectady, New York R L Mancini, Alternate, National Electrical Manufacturers Association, New York, New York NATIONAL MACHINE TOOL BUILDERS’ ASSOCIATION Thomas Lenhart, The Cleveland Twist Drill Company, Cleveland, Ohio REED ROLLED THREAD DIE COMPANY Joseph f Dickson, Reed Rolled Thread Die Company, Nolden, Massachusetts SOCIETY OF AUTOMOTIVE ENGINEERS C H Baker, Jr., Muncie,Indiana J E Long, GM Corporation, GM Technical Center, Warren, Michigan L R Strang, Caterpillar Tractor Company, E Peoria, Illinois vi Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh COMPUTERS & BUSINESS EQUIPMENT MANUFACTURERS ASSOCIATION H G Atwater /observer), International Rusiness Machine Corporation, Endicott New York SOCKET SCREW PRODUCTS BUREAU E J Heldmann, The Holo-Krome Screw Corporation, Hartford, Connecticut TELEPHONE GROUP, THE R H Van Horn, Bell Telephone Laboratories, Inc., Columbus, Ohio F P Balacek, Alternate, Bell Telephone Laboratories, Inc., Columbus, Ohio L L Parrish, Alternate, Western Electric Company, Inc., Chicago, Illinois U.S MACHINE, CAP, WOOD & TAPPING SCREW BUREAU R M Byrne, U.S Screw Service Bureaus, New York, New York E F Tauscher, Alternate, Pheoll Manufacturing Company, Chicago, Illinois U S DEPARTMENT OF THEARMY lrwin Rosen, USA Mobility Equipment Company, Fort Belvoir, Virginia M L Fruechtenicht, Alternate, Redstone Arsenal, Alabama John McAdams, Alternate, U.S Army Materiel Command, Alexandria, Virginia Watervliet Arsenal J J Fiscella, Watervliet,NewYork U.S DEPARTMENT OF COMMERCE National Bureau o f Standards A G Strang, National Bureau of Standards, Optical Physics Division, Washington, D.C U.S DEPARTMENT O F T H ENAVY Naval Ship Engineering Center (NSSCI J Kelly, Naval Ship Systems Command, Washmgton, D.C U.S DEPARTMENT OF THE AIR FORCE Edward Sosnowski, Aeronautical Systems Division, Wright-Patterson Air Force Base, Dayton, Ohio F Hannon, Alternate Aeronautical Systems Division, Wright-Patterson Air Force Base, Dayton, Ohio R B Norwood, Robbins Air Force Base, Georgia VALLEY BOLT COMPANY C 0.Franklm, Marion,Iowa VAN KEUREN COMPANY R W Lamport, The Van Keuren Company, Watertown, Massachusetts INDlVlDUAL MEMBERS S C Adamek, (observerl, Pheoll Manufacturing Company, Chicago, lllinois C T Appleton, Jefferson,Massachusetts W E Bour, Santa Monica, California W S Brown, Roanoke, Virginia J F Cramer, Des Moines,Washington R B Donahue, Xerox Corporatlon, Rochester, New York E W Drescher, Bulova Watch Company, Inc., Flushing, New York H Fullmer(observer), SilverSprings,Maryland W E Hay, The Pipe Machinery Company, Wickliffe, Ohio A R Machell, Jr., Xerox Corporation, Rochester, New York A E.Masterson, Watervliet, New York P V Miller(observerl, SantaMaria,California H G Muenchinger, Continental Screw Company, New Bedford, Massachusetts Frank Tisch, Desert Hot Springs, California R P Trowbridge, GM Technical Center, Warren, Michigan J E Watson, Philadelphia,Pennsylvania vii Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh SOCIETY OF MANUFACTURING ENGINEERS M Davidson, Thredco Company, Troy, Michigan J S Urso, Sepulveda,California Dale Story, The Bcndix Corporation, South Beloit Illinois D N Badgley, Chairman, Clark Equipment Company, Battle Creek, Michigan W E Bour, Gardena, California R J Browning, Southern Gage Company, Erin, Tennessee J A Casner, Youngstown Steel Company, Youngstown, Ohio W 0.Clinedinst, Consulting Engineer, Pittsburgh, Pennsylvania M Davidson, Southfield, Michigan H W €//ison, General Motors Technical Center, Warren, Michigan L S Feldheim, Secretary, The Weatherhead Company, Cleveland, Ohio J 0.Heinze, Regal-Beloit Corporation, South Beloit, Illinois J S Hinske, Parker-Hannifin Corporation, Tube Fitting Division, Cleveland, Ohlo D F Hubbard, Long Island Lighting Company, Hicksville, New York S Kanrer, The Hanson-Whitney Company, Hartford, Connecticut W A Keaton, Vice Chairman, General Motors Technical Center Warren, Michigan W C Matlock, Stockham Valves & Fittings, Birmingham, Alabama R S Piofrowski, Mack Trucks, Inc., Allentown, Pennsylvania P V Pastore, Regal-Beloit Corporation, South Beloit, Illinois W M Roll, Deere & Company, Moline, Illinois M Rose, Southern Gage Company, Erin, Tennessee R J Ross, Wheeling-Pittsburgh Steel Corporation, Benwood, West Virginia C J Schim, Ford Motor Company, Dearborn, Michigan J Shields, Jackes-Evans Manufacturing Company, Jackson, Mississippi J Turton, The Bendix Corporation, South Beloit, Illinois A G Strang, National Bureau of Standards, Washington, D.C viii Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled w PERSONNEL OF SUBCOMMITTEE NO 20 O N PIPE T H R E A D S Product Section 1Threads Introduction 1.1 Thread 1.2Types 1.3 Thread Designations and Notation 1.3.1 NPTF Thread Class 1.3.2 Designation of Plated Threads 1.4 Applications 1.4.1 Type 1.4.1.1 NPTF 1.4.1.2 PTF-SAE SHORT 1.4.1.3 NPSF 1.4.1.4 NPSI 1.4.2 CLASS 1.4.2.1 NPTFCLASS 1.4.2.2 NPTFCLASS 1.5 Assembly Limitations 1.6 Thread Form and Tolerance 1.7 Basic Dimensions 1.7.1 NPTF Threads 1.7.2 PTF-SAE SHORT, External Threads 1.7.3 PTF-SAE SHORT, Internal Threads 1.7.4 NPSF Threads 1.7.5 NPSI Threads Appendix A A.1 A.2 LetterSymbolsandFormulas Symbols Designating the Dimensions of Pipe Threads Formulas for Diameter and Length of Thread 3 3 3 4 4 4 7 10 10 11 11 11 14 SpecialShort,SpecialExtraShort,Fine,andSpecialDiameter-Pitch CombinationDrysealPipeThreads C.1 DrysealSpecialShortTaperPipeThread,PTF-SPLSHORT C.2DrysealSpecialExtraShortTaperPipeThread,PTF-SPLEXTRASHORT C.3 Limitations o f Assembly C.4DrysealFineTaperThreadSeries,F-PTF C.5DrysealSpecialDiameter-PitchCombinationSeries,SPL-PTF C.6 Formulas for DiameterandLength o f Thread Designations C.7 15 15 15 15 16 16 16 16 AppendixBSuggestedTap Drill Sizes for InternalDrysealPipeThreads Appendix C Table Page 1 RecommendedLimitations of AssemblyAmongtheVariousTypes of DrysealThreads ReferenceDimensions for AssembledEngagement of DrysealPipeThreads Basic Dinlensions for NPTFThreads Basic Dimensions for PTF-SAESHORT,ExternalThreads ix 5 Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh CONTENTS A Pipe ThreadSymbols B Suggested Tap Drill Sizes for Internal DrysealPipe Threads C Basic Dimensions of Dryseal Fine Taper Pipe Thread F-PTF C Basic Dimensions of Dryseal Special Taper Pipe Thread SPL-PTF (For Thin Wall Nominal Size ODTubing) Figure Extreme Mating Conditions for DrysealPipe Threads Thread Form and Limits on Root and Crest Tuncation of Product Threads AI Application of Pipe ThreadSymbols C Comparison of Special Dryseal Threads with Standard Length Dryseal Threads X Page 10 10 12 14 18 19 13 17 Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh Table Basic Dimensions for PTF-SAE SHORT.InternalThreads Dimensional Data for NPSF Threads Dimensional Data for NPSI Threads AMERICAN NATIONAL STANDARD INCH DRYSEAL PIPE THREADS SECTION I PRODUCT THREADS 1.1 Introduction Dryseal pipe threads are based on the USA (American) pipe thread, however, they differ from the USA (American) pipe thread in that they are designed to seal pressuretight joints without the necessity of using sealing compounds To accomplish this some modification of thread form and greater accuracy in manufacture is required.Therootsofboththeexternal and internal threads are truncated slightly more than thecrests,i.e.rootshavewiderflatsthancrests, so that metal-to-metal contact occurs at the crests and roots coincident with or prior to flank contact, see Figure1.Thus as thethreadsareassembled.by wrenching, the roots of the threads crush the sharper crestsofthematingthreads.Thissealingactionat both the major and minor diameters tends to prevent spiral leakage and makes the joints pressuretight without the necessity of using sealing compounds, provided that the mating threads are in accordance with standardspecificationsandtolerancesandarenotdamaged by galling in assembly The control of crest and root truncation is simplified by the use of properly designed threading tools Also, it is desirable that both external and internal threads have full thread height for the L length.However,wherenotfunctionally objectionable,theuse of acompatiblelubricant or sealantmaybeusedtominimizethepossibilityof galling This is desirableinassemblingDrysealpipe threads in refrigeration and other systems to effect a pressuretight seal.' 1.1.1 Inordertoobtainapressuretightsealusing Dryseal pipe threads without a sealer, it is necessary to hold crest and root truncation of both internal and externalthreadswithinthelimitsspecified.Unless this is done by use of threading tools with the crest and root truncation controlled so as to assure repro'The refrigeration industry has generally accepted the asealant toobtainanabsolutepressuretightjoint, assembling taper pipe threads use of when duction on the product threads, it is necessary t o use a system of measuring or a system ofgaging and measuring to determine conformance 1.1.2 Evenwithouttruncation gages, thestandard practice of using two separate thread gages for Dryseal pipethreads,eachwithadifference in truncation, length of engagement and point of engagement, provides a more detailed check of angle, lead and taper deviations than is required for non-dryseal taper pipe threads 1.1.3 One method of checking crest truncation is by using step plain gages It should be recognized that this method may give misleadingresultsinthatthe crest truncation of the product threads is always less (flat narrower) than that indicated by the position of the gages, the degree of inconsistency depending on theangle,leadandtaperdeviationspresentinthe product thread 1.1.4 Another method employs both crest and root truncation check gages The root check gage is m'ade withathreadformhavinganincludedangle of 50 degreesandwithasmaller gage crestflatthanthe root flat to be checked The major diameter of this gageis controlled in relationto gaging steps in a similar manner to the plain step crest check gage Like the crest check gage, the results may be somewhat misleading except that in the case of the root check gage, the root truncation of the product thread is always more (flat wider) than is indicated by the position of the gages 1.1.5 Unless lead, angle and taper of product threads are very well controlled, use of step crest and root check gages will result in productthreadswithnarrower crest flats and wider root flats than envisioned by the dryseal tolerances Use of such a gaging system could result in rejection of threads which would actuallyconform to thedrysealtolerancesspecified The only completely reliable referee method for determiningwhethercrestandroottruncationhasbeen Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled w ANSI 81.20.3-1976 ANSI 81.20.3-1976 Table Dncommended Limitation of Assembly among the Various Types of Dryreal Threads; For Assembly with Internal Dryseal thread: External Dryseal thread: Type Table Table Description NPTF (tapered), ext thd z2s3 Type 22,4 32,5 42,5*6 PTF-SAE SHORT (tapered) ext thd Description NPTF (tapered), int thd PTF-SAE SHORT (tapered), int thd NPSF (straight), int thd NPSI (straight), int thd NPSI (straight), int thd NPTF (tapered), int thd An assembly with straight internal pipe threads and taper external pipe threads is frequently more advantageous than an all taperthreadassembly,particularly in automotive and other allied industries where economy and rapid production are major considerations Dryseal threads are not used in assemblies in which both components have straight pipe threads Pressuretight joints without the use of a sealant can best be assured where both components are threaded with NPTF (full length threads), since theoretically interference (sealing) occurs at all threads, but there are two less threads engaged than for NPTF assemblies When straight internal threads are used, there is interference only at one thread depending on ductility of materials PTF-SAE SHORT external threads are primarily intended for assembly with type 4-NPSl internal threads but can also be used with type I-NPTF internal threads They are not designed for, and at extreme tolerance limits may not assemble with, type 2-PTFSAE SHORT internal threads or type 3-NPSF internal threads 'PTF-SAESHORTinternalthreadsareprimarilyintendedforassemblywithtype1-NPTFexternal threads They are not designed for and at extreme tolerance limits may not assemble with, type 2-PTFS A E SHORT external threads 'There is no external straight Dryseal thread 6NPSI internal threads are primarily intended for assembly with type 2-PTF-SAE SHORT external threads but w i l l also assemble with full length type NPTF external threads I Table Reference Dimensions for Assembled Engagement of Dryseal Pipe Threads Approximate Length of Thread Engagement I I Size I y8 Yl ',fa % - - 1% 2% - - Thread, L, 0.25 0.27 0.4 05 0.55 14 0.68 11% 11% - + 3p Internal NPTF Internal Thread, L, +2.5~ ::2;I 14 - 11% - 11% % 1% 27 - 27 - 18 - 18 '116 NPTF External Thread Assembled Into t l - NPSI I 0.70 1.06 l.14 f NPSF lnternal Thread, F'TF-SAE SHORT Internal Thread, L , +2P L, + ~ Approximate Length of Thread Engagement PTF-SAE SHORT External Thread Assembled Into NPSI Internal Thread, L, + 2P NPTF Internal Thread, L, + ~ NPSF lnternal Thread, F'TF-SAE SHORT lnternal Thread, L, L , + 0.5p + 1P 0.25 0.37 0.38 0.23 0.23 0.34 0.35 0.22 0.22 0.31 0.32 0.23 0.23 0.34 0.35 0.22 0.22 0.31 0.32 0.20 0.20 0.28 0.29 0.1 0.18 0.50 0.52 0.62 0.64 0.46 0.48 0.66 0.57 0.59 0.43 0.45 0.53 0.55 0.46 0.48 0.57 0.59 0.43 0.45 0.53 0.55 0.39 0.4 0.49 0.36 0.37 0.51 0.44 0.46 0.64 0.68 0.59 0.65 0.61 0.99 0.93 1.08 1.02 0.55 0.57 0.87 0.95 0.5Y 0.61 0.93 1.02 0.55 0.57 0.87 0.95 0.5 0.52 0.81 0.89 0.46 0.48 0.74 0.83 0.26 0.27 Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh AMERICAN NATIONAL STANDARD INCH DRYSEAL PIPE THREADS ANSI 61.20.3-1976 0 0 ~ w ~ p r ' m 0 0 - 99999 ooooc a a a a n m w m m m W N ~ O W -7979 0 0 0 0 u m m w m 0 0 0 0 0 0 0 a a a n a m o o m u c m r - w w -0G"O 0 0 0 0 0 u m m w m w 0 0 0 0 0 0 0 0 0 0 0 0 C m M - W ocoo0 0 0 0 0 0 0 0 ~ - - m v , m ~ a r - m co000 ooc00 0 0 0 0 c m ~ m m u u v , U , 88888 ococ'o a n a a a b w o o m r n P W W v , 99999 coocc vlmmrnrn m u u v , \ D ooooc oooco 0 0 0 0 0 0 0 ~ m Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled wh AMERICAN NATIONAL STANDARD INCH DRYSEAL PIPE THREADS - 27 - - 18 18 0.08696 0.08696 I2500 0.1 2500 0.07143 0.07143 0.08696 0.08696 0.03704 0.03704 0.05556 0.05556 Inch 1.79609 2.26902 2.71953 3.34062 0.75843 0.96768 1.21363 1.55713 0.27 I I8 0.36351 0.47739 0.61201 Inch (E,) ) Ext 0.28750 0.38000 0.M250 0.63750 Inch (1,:1) PD at Large End of 1.82234 2.29627 2.76216 3.38850 - 1.84130 2.31630 2.79062 3.41562 0.77843 0.79 I79 0.98887 1.23863 1.58338 1.60130 0.28 I 18 0.37360 0.49163 0.62701 Inch (E, Int Thread Thread Ext PD at Large End of PD at Small Lkd o f Small ) T Thd 1.7798 2.2527 2.6961 3.3172 0.2642 0.3566 0.4670 0.6016 5.46 6.13 5.01 4.83 7.47 7.64 7.85 I3 D.7235 8.32 D.7565 8.70 1.1375 9.10 1.2000 9.60 - ).4200 ).4360 ).6820 ).7660 ) 1600 7.05 7.12 7.23 7.34 Inch Thd - ~ 0.5337 D.5457 3.6828 D.7068 ~ ~ 0.745 ).3200 4.48 ).3390 4.75 0.9543 1.00179 1.1973 1.4000 1.25630 4.60 1.5408 ).4200 4.83 Inch 0.261 I 0.2639 0.4018 0.4078 ~ ~ Thread 4.32 1.1615 4.36 ).2278 4.10 ).2400 4.32 Inch (I3 Thread Int I h d of PD a t f 0.2765 0.2747 0.3781 0.3781 0.2163 0.2043 0.2547 0.2620 I I ' Inch 3.180 3.159 3.025 3.025 3.028 2.860 2.929 3.013 1.0000 0.3035 1.0312 0.3205 1.5156 0.4555 1.5781 0.4340 0.75000.2137 0.75000.2067 0.93750.2828 0.96880.2868 3.0750.3750 0.1011 3.072 0.37500.1024 2.892 0.5625 0.1740 2.791 0.5625 0.1678 P + %P) I Thd Inch 0.1 139 0.1112 0.1607 I547 Inch (V Table Basic Dimensions for NPTF Threads - 3.49 3.69 3.64 3.47 2.99 2.89 3.25 3.30 2.73 2.76 3.13 3.02 Thd - ~ I,'ull - 7.48 7.75 7.60 7.83 7.32 7.36 I O 7.32 = 1.912 2.381 2.893 3.5 18 0.850 1.060 1.327 1.672 0.315 0.407 0.546 0.681 Thd Inch - ~ 0.6809 7.83 0.6969 8.01 1.0570 8.46 1.1410 9.13 0.5343 0.5533 0.6609 0.6809 0.27 I I 0.2726 0.3945 0.4067 Inch Thread (L, + L , P Length of Internal L / a External thread tabulated full thread lengths include chamfers not exceeding one pitch (thread) length b Internalthreadtabulatedfullthreadlengthsdo not includecountersinkbeyondtheintersection o f thepitchlineandthechamfercone(gagingreferencepoint) -11% 2% - - I % -11% I -11% I % - 11% Ya - 14 % - 14 '1, % 'I8 - 27 '116 Size Pitch (P) 1.7.1 NPTF Threads 1.7 Basic Dimensions - 1.9000 2.3750 2.8750 3.5000 0.8400 I os00 1.3150 1.6600 0.3125 0.4050 0.5400 0.6750 Inch 2 g & 01 E D Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled w ANSI 81.20.3-1976 1.7.2 PTF-SAE SHORT, External Threads + AT MIN EXT THDPD Pitch (PI Size Inch ?4 - 18 ’/8 - 18 Ya 34 1% 1% 2% PD at End of Ext Thread E, Short Inch - 27 0.03704 ‘I8 - 27 - 14 14 - 11% - Lz AT MAXINTTHD Hand Engagement (L,Short) Inch Thd Inch Thd PD SHORT t I ONE TURN I- THREADFULL T ‘116 - _‘ + 4p HAND ENGAGEMENT ( L SHORT) ONE TURN FULL THREAD - -1 DIE CHAMFER AND SHOULDERCLEARANCE * Vanish Thds Length of Full Thread (L,Short)a PI us Length Draw I (V + 1P+ %p) Inch Thd Inch Thd - Length of Internal Full Thread (L Short :4p)b Inch Thd - 0.27349 0.03704 0.36582 0.05556 0.48086 0.05556 0.61548 0.1600 0.1615 0.2278 0.2400 4.32 4.36 4.10 4.32 0.1230 0.1244 0.1722 0.1844 3.32 3.36 3.10 3.32 0.2241 0.2268 0.3462 0.3522 6.05 6.1 6.23 6.34 0.0926 0.0926 0.1 389 0.1389 2.50 2.50 2.50 2.50 0.3167 0.3194 0.4851 0.4911 0.1011 0.1024 0.1740 0.1678 2.73 2.76 3.13 3.02 0.271 0.2726 0.3945 0.4067 7.32 7.36 7.10 7.32 0.07143 0.76289 0.07143 3.97214 0.08696 1.21906 0.3200 3.3390 3.4000 1.4200 4.48 4.75 4.60 4.83 0.2486 0.2676 0.3 130 0.3330 3.48 3.75 3.60 3.83 0.4623 0.4743 0.5958 0.6198 6.47 6.64 6.85 7.13 0.1786 D 1786 3.2 174 3.2174 2.50 2.50 2.50 2.50 0.6409 0.6528 0.8132 0.8372 0.2137 0.2067 0.2828 0.2868 2.99 2.89 3.25 3.30 0.5343 0.5533 0.6609 0.6809 7.48 7.75 7.60 7.83 3.4200 3.4360 3.6820 3.7660 4.83 5.01 5.46 6.13 0.3330 0.3490 0.5570 0.6410 3.83 4.01 4.46 5.13 0.6365 0.6695 1.0125 1.0750 7.32 7.70 8.10 8.60 3.2 174 9.2 174 0.3125 0.3 125 2.50 2.50 2.50 2.50 0.8539 0.8869 1.3250 1.3875 0.3035 0.3205 0.4555 0.4340 3.49 3.69 3.64 3.47 0.6809 0.6969 1.OS70 1.1410 733 8.01 8.46 9.1 I 11% 0.08696 1.56256 - 11% 0.08696 - 11% 0.08696 -0.12500 0.12500 - 1.80152 2.27445 2.72734 3.34844 - =- Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled w AMERICAN NATIONAL STANDARD INCH DRYSEAL PIPE THREADS ANSI 81.20.3-1976 1.7.3 PTF-SAE SHORT, Internal Threads ATMAX INT THD P D EO E3 ( S E E TABLE Table Basic Dimensions for ( P) PD at End of Int Thread (E, Short) inch Inch Inch Thd 0.03104 0.03704 0.05556 0.05556 0.27887 0.31129 0.48815 0.62354 0.1600 0.1615 0.2278 4.32 4.36 4.10 4.32 14 14 -11% 1% - 11% 0.07143 0.07143 0.08696 0.08696 0.11391 0.98441 1.23320 1.57795 0.3200 0.3390 1% - 11% - IlYZ 2% - - 0.08696 0.08696 0.12500 0.12500 1.81691 2.29084 2.15435 3.38069 Pitch Size ‘I16 - 27 ‘18 ‘A - - % ?4 27 18 18 - a Internal thread tabulated full thread lengths chamfer cone (gaging reference point) El ( SHORT ) P T F S A E Short, Internal Threads Hand Engagement (L, Short) (L,) Inch Length of Internal Full Thread (L, Short + L,)a Hole Depth For SAE Short Tap Thd inch Thd Inch 3.32 3.36 3.10 3.32 0.2341 0.2356 0.3389 0.3511 6.32 6.36 6.10 6.32 0.4564 0.4518 0.6122 0.6844 0.4200 4.48 0.2486 3.48 4.15 0.2616 3.15 4.60 0.4000 0.3130 3.60 4.83 0.3330 3.83 0.4629 0.4819 0.5139 0.5939 6.48 6.15 6.60 6.83 0.8915 0.9105 1.0956 1.1156 0.4200 0.4360 0.6820 0.1660 4.83 5.01 5.46 6.13 0.5939 0.6099 0.9320 1.0160 6.83 7.01 1.46 8.13 1.1156 1.1316 1.6820 1.7660 0.1230 0.1244 0.1722 0.2400 0.1844 0.3330 0.3490 0.5570 0.6410 3.83 4.01 4.46 5.13 d o n o t include countersink beyond the intersection of the pitch line and the , Copyrighted material licensed to Stanford University by Thomson Scientific (www.techstreet.com), downloaded on Oct-05-2010 by Stanford University User No further reproduction or distribution is permitted Uncontrolled w / AMERICAN NATIONAL STANDARD INCH DRYSEAL PIPE THREADS 1.7.4 NPSF ANSI 81.20.3-1976 Threads Table Dimensional Data