UL 21-2007 Standard for LP-Gas Hose.doc

ul 21lp-gas hoseul copyrighted material not authorized for further reproduction or distribution without permission from ulthis pdf standard downloaded from december 20, 2007 ul 21tr3underwriters laboratories inc. (ul)333 pfingsten roadnorthbrook, il 60062-2096ul standard for safety for lp-gas hose, ul 21tenth edition, dated december 20, 2007summary of topicsthe tenth edition of the standard for lp-gas hose, ul 21, has been issued to reflect the latestansi approval date and to incorporate formatting and editorial revisions.ul standards for safety are developed and maintained in the standard generalized markup language (sgml). sgml - an international standard (iso 8879-1986) - is a descriptive markup language that describes a documents structure and purpose, rather than its physical appearance on a page. due to formatting differences resulting from the use of uls new electronic publishing system, please note that additional pages (on which no requirements have been changed) may be included in revision pages due to relocation of existing text and reformatting of the standard.the revised requirements are substantially in accordance with uls proposal(s) on this subject datedoctober 5, 2007.as indicated on the title page (page 1), this ul standard for safety is an american national standard. attention is directed to the note on the title page of this standard outlining the procedures to be followed to retain the approved text of this ansi/ul standard.the ul foreword is no longer located within the ul standard. for information concerning the use and application of the requirements contained in this standard, the current version of the ul foreword is located on ulstandardsinfonet at: /ulforeword.htmlthe master for this standard at uls northbrook office is the official document insofar as it relates to a ul service and the compliance of a product with respect to the requirements for that product and service, or if there are questions regarding the accuracy of this standard.uls standards for safety are copyrighted by ul. neither a printed copy of a standard, nor the distribution diskette for a standard-on-diskette and the file for the standard on the distribution diskette should be altered in any way. all of uls standards and all copyrights, ownerships, and rights regarding those standards shall remain the sole and exclusive property of ul.all rights reserved. no part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form by any means, electronic, mechanical photocopying, recording, or otherwise without prior permission of ul.revisions of ul standards for safety are issued from time to time. a ul standard for safety is current only if it incorporates the most recently adopted revisions.ul provides this standard as is without warranty of any kind, either expressed or implied, including but not limited to, the implied warranties of merchantability or fitness for any purpose.ul copyrighted material not authorized for further reproduction or distribution without permission from ulthis pdf standard downloaded from in no event will ul be liable for any special, incidental, consequential, indirect or similar damages, including loss of profits, lost savings, loss of data, or any other damages arising out of the use of or the inability to use this standard, even if ul or an authorized ul representative has been advised of the possibility of such damage. in no event shall uls liability for any damage ever exceed the price paid for this standard, regardless of the form of the claim.ul will attempt to answer support requests concerning electronic versions of its standards. however, this support service is offered on a reasonable efforts basis only, and ul may not be able to resolve every support request. ul supports the electronic versions of its standards only if they are used under the conditions and operating systems for which it is intended. uls support policies may change from time-to-time without notification.ul reserves the right to change the format, presentation, file types and formats, delivery methods and formats, and the like of both its printed and electronic standards without prior notice.purchasers of the electronic versions of uls standards for safety agree to defend, indemnify, and hold ul harmless from and against any loss, expense, liability, damage, claim, or judgement (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic standard on the purchasers computer system.if a single-user version electronic standard was purchased, one copy of this standard may be stored on the hard disk of a single personal computer, or on a single lan file-server or the permanent storage device of a multiple-user computer in such a manner that this standard may only be accessed by one user at a time and for which there is no possibility of multiple concurrent access.if a multiple-user version electronic standard was purchased, one copy of the standard may be stored on a single lan file-server, or on the permanent storage device of a multiple-user computer, or on an intranet server. the number of concurrent users shall not exceed the number of users authorized.electronic standards are intended for on-line use, such as for viewing the requirements of a standard, conducting a word search, and the like. only one copy of the standard may be printed from each single-user version of an electronic standard. only one copy of the standard may be printed for each authorized user of a multiple-user version of an electronic standard. because of differences in the computer/software/printer setup used by ul and those of electronic standards purchasers, the printed copy obtained by a purchaser may not look exactly like the on-line screen view or the printed standard.an employee of an organization purchasing a ul standard can make a copy of the page or pages being viewed for their own fair and/or practical internal use.the requirements in this standard are now in effect, except for those paragraphs, sections, tables, figures, and/or other elements of the standard having future effective dates as indicated in the note following the affected item. the prior text for requirements that have been revised and that have a future effective date are located after the standard, and are preceded by a superseded requirements notice.new product submittals made prior to a specified future effective date will be judged under all of the requirements in this standard including those requirements with a specified future effective date, unless the applicant specifically requests that the product be judged under the current requirements. however, if the applicant elects this option, it should be noted that compliance with all the requirements in this standard will be required as a condition of continued listing and follow-up services after the effective date, and understanding of this should be signified in writing.copyright 2007 underwriters laboratories inc.this standard consists of pages dated as shown in the following checklist:pagedate1-18 . december 20, 2007this pdf standard downloaded from no text on this pageul copyrighted material not authorized for further reproduction or distribution without permission from uldecember 20, 20071ul 21standard for lp-gas hoseansi/ul 21-2007the first and second editions were titled hose for conducting lp-gas.first edition september, 1955second edition march, 1964third edition november, 1967fourth edition february, 1973fifth edition august, 1978sixth edition april, 1980seventh edition june, 1986eighth edition december, 1991ninth edition june, 1995tenth editiondecember 20, 2007the most recent designation of ansi/ul 21 as an american national standard (ansi) occurred on december 18, 2007. the ansi approval for this standard does not include the cover page, transmittal pages, or title page.this ansi/ul standard for safety, which consists of the tenth edition, with revisions through december 20, 2007, is under continuous maintenance, whereby each revision is ansi approved upon publication.an effective date included as a note immediately following certain requirements is one established by underwriters laboratories inc. and is not part of the ansi approved standard.revisions of this standard will be made by issuing revised or additional pages bearing their date of issue. a ul standard is current only if it incorporates the most recently adopted revisions, all of which are itemized on the transmittal notice that accompanies the latest set of revised requirements. comments or proposals for revisions on any part of the standard may be submitted to ul at any time. proposals should be submitted via a proposal request in uls on-line collaborative standards development system (csds) at .copyright 1978, 2007 underwriters laboratories inc.december 20, 2007lp-gas hose - ul 2117this pdf standard downloaded from no text on this pageul copyrighted material not authorized for further reproduction or distribution without permission from ulcontentsintroduction1 scope . .52 general . .52.1 units of measurement . .52.2 undated references . .5construction3 tube and cover . .64 reinforcement . .65 inside diameter . .66 thickness of tube or cover . .7performance7 proof-pressure test . .77.1 general . .77.2 apparatus . .87.3 method . .88 hydrostatic strength test . .88.1 general . .88.2 apparatus . .88.3 method . .99 adhesion test . .99.1 general . .99.2 apparatus . .99.3 method . .1010 tensile strength and elongation tests . .1010.1 general . .1010.2 apparatus . .1010.3 method . .1111 accelerated air-oven aging test . .1111.1 general . .1111.2 method . .1212 ozone exposure . .1212.1 general . .1212.2 apparatus . .1212.3 method . .1213 repeated bending test . .1313.1 general . .1313.2 apparatus . .1313.3 method . .1314 repeated bending proof pressure test . .1414.1 general . .1414.2 apparatus . .1414.3 method . .1415 permeation test . .1415.1 general . .1415.2 apparatus . .14this pdf standard downloaded from 15.3 method . .1416 immersion tests of rubber tube and cover . .1516.1 tensile strength and ultimate elongation . .1516.2 volumetric swelling . .1617 low temperature test . .1717.1 general . .1717.2 apparatus . .17manufacturing and production tests18 general . .18marking19 general . .18introduction1 scope1.1 these requirements cover hose in sizes up to and including a nominal internal diameter of 4 in (102 mm) for conducting liquefied petroleum gas intended to be installed in closed systems in compliance with the standard of the national fire protection association for the storage and handling of liquefied petroleum gases, nfpa 58. the hose is made for a maximum working pressure of 350 pounds per square inch gauge (psig) (2400 kpa). hose in sizes larger than 2 in (50.8 mm) is not intended for use on reels.1.2 hoses covered by this standard are intended for use at temperatures within the range of minus 40c (minus 40f) to plus 60c (140f), or minus 54c (minus 65f) to plus 60c.1.3 this standard does not apply to:a) couplings nor their method of attachment;b) gas appliance connectors for handling fuel gases at 5 psig (34.5 kpa) or less, nor to metallic hose intended for use in oil transportation piping, in petroleum refinery piping, or in gas transmission and distribution piping systems; orc) hose intended for use in automotive applications or hose intended for use in confined areas. hose for use in automotive applications is investigated under the outline of investigation forlp-gas fuel hose and hose assemblies for vehicle engines, subject 1785.2 general2.1 units of measurement2.1.1 if a value for measurement is followed by a value in other units in parentheses, the second value may be only approximate. the first stated value is the requirement.2.2 undated references2.2.1 any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard.this pdf standard downloaded from construction3 tube and cover3.1 the tube or lining of a hose shall be made from synthetic rubber of the oil-resistant type. for hose up to and including the 2-in (50.8 mm) size, a rubber cover may be employed but is not required if the outer braid is impregnated with a rubber cement or compound. for hose larger than the 2-in size, a rubber cover shall be employed. a tube or a cover shall be smooth, of uniform thickness, free from defects in workmanship, and free from pitting, blisters, or other imperfections. intentional pricking of a cover shall not be considered an imperfection. this requirement is not intended to exclude the use of a corrugated cover.4 reinforcement4.1 a reinforcement shall be provided and shall be of cotton, synthetic fibers, or corrosion-resistant material such as stainless steel, or any combination thereof, evenly and firmly applied over the tube. the ply or plies shall be impregnated with a rubber compound which shall cause the plies to adhere firmly to each other and to the tube and cover.5 inside diameter5.1 the internal diameter of a hose shall be equal to the nominal diameter 1/32 in (0.8 mm) for sizes up to and including 3/4 in (19.1 mm), and 1/16 in (1.6 mm) for larger sizes.5.2 a tapered plug gauge of wood or metal having a taper of 3/8 in per ft (31.3 mm/m) marked to indicate variation of 1/64 in (0.4 mm) in diameter, a set of wood or metal plug gauges, straight or ball type, in increments of 0.005 in (0.13 mm), or in some cases, see 5.3, an expanding ball gauge and micrometer or other equivalent means to accurately measure the expanded ball, is to be used.5.3 the end of the hose is to be cut square. if a tapered plug gauge is used, the plug gauge is to be inserted in the hose sample until a close fit is obtained without forcing. the diameter of the gauge at the end of the sample, to the nearest 1/64 in (0.4 mm), is to be recorded as the internal diameter of the hose. if a set of straight or ball-type plug gauges is used, the diameter of the gauge, which when inserted in the hose sample gives