1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 21 LP-Gas Hose STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER
2、 REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for LP-Gas Hose, UL 21 Eleventh Edition, Dated December 15, 2014 Summary of Topics These revisions to ANSI/UL 21 include the following: 1. Revision to the moist ammonia-air stress cracking test The revised requirements a
3、re substantially in accordance with Proposal(s) on this subject dated May 19, 2017. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. All rights reserved. No part of this publication may be reproduced, stored in a r
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7、nd hold UL harmless from and against any loss, expense, liability, damage, claim, or judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchaser is storing an electronic Standard on the purchasers computer system. JULY 28, 2017 UL 21 tr1UL COPYRIGH
8、TED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JULY 28, 2017 UL 21 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL DECEMBER 15, 2014 (Title Page Reprinted: July 28, 201
9、7) 1 UL 21 Standard for LP-Gas Hose The First and Second editions were titled Hose for Conducting LP-Gas. First Edition September, 1955 Second Edition March, 1964 Third Edition November, 1967 Fourth Edition February, 1973 Fifth Edition August, 1978 Sixth Edition April, 1980 Seventh Edition June, 198
10、6 Eighth Edition December, 1991 Ninth Edition June, 1995 Tenth Edition December, 2007 Eleventh Edition December 15, 2014 This ANSI/UL Standard for Safety consists of the Eleventh Edition including revisions through July 28, 2017. The most recent designation of ANSI/UL 21 as an American National Stan
11、dard (ANSI) occurred on July 27, 2017. ANSI approval for a standard does not include the Cover Page, Transmittal Pages and Title Page. 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-Li
12、ne Collaborative Standards Development System (CSDS) at https:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of ULs Standards and all copyrights, ownerships, and rights regarding those Standards shall remain th
13、e sole and exclusive property of UL. COPYRIGHT 2017 UNDERWRITERS LABORATORIES INC. ANSI/UL 21-2017UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL SEPTEMBER 29, 2015 LP-GAS HOSE - UL 21 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHOR
14、IZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .5 2 General 5 2.1 Units of measurement .5 2.2 Undated references .5 CONSTRUCTION 3 Tube and Cover 6 4 Reinforcement 6 5 Inside Diameter .6 6 Thickness of Tube or Cover 7 7 Assembly Couplings 7 PER
15、FORMANCE 8 Proof-Pressure Test .8 8.1 General 8 8.2 Apparatus .8 8.3 Method 8A 9 Hydrostatic Strength Test .8A 9.1 General .8A 9.2 Apparatus 8A 9.3 Method 8A 10 Adhesion Test 8B 10.1 General 8B 10.2 Apparatus .8B 10.3 Method .8B 11 Tensile Strength and Elongation Tests .9 11.1 General 9 11.2 Apparat
16、us 9 11.3 Method .11 12 Accelerated Air-Oven Aging Test .11 12.1 General .11 12.2 Method .12 13 Ozone Exposure 12 13.1 General .12 13.2 Apparatus .12 13.3 Method .12 14 Repeated Bending Test .13 14.1 General .13 14.2 Apparatus .13 14.3 Method .13 15 Repeated Bending Proof Pressure Test 14 15.1 Gener
17、al .14 15.2 Apparatus .14 15.3 Method .14 16 Permeation Test 14 16.1 General .14 SEPTEMBER 29, 2015 LP-GAS HOSE - UL 21 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 16.2 Apparatus .14 16.3 Method .14 17 Immersion Tests of Rubber Tube and
18、 Cover .15 17.1 Tensile strength and ultimate elongation 15 17.2 Volumetric swelling .16 18 Low Temperature Test 17 18.1 General .17 18.2 Apparatus .17 19 Pull Force Test 18 19.1 General .18 19.2 Apparatus .18 19.3 Method .18 20 Moist Ammonia-Air Stress Cracking Test 18 MANUFACTURING AND PRODUCTION
19、TESTS 21 General 19 MARKING 22 General 20 DECEMBER 15, 2014 LP-GAS HOSE - UL 21 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover hose and hose assemblies in sizes up to and including a nomina
20、l internal diameter of 4 in (102 mm) for conveying liqueed petroleum gas (LP-Gas) intended to be installed in closed systems in compliance with the Standard of the National Fire Protection Association Liqueed Petroleum Gas Code, NFPA 58. The hose or hose assembly is intended for a maximum working pr
21、essure of 350 pounds per square inch gauge (psig) (2400 kPa) for use at temperatures within the range of minus 40C (minus 40F) to plus 60C (140F), or minus 54C (minus 65F) to plus 60C. Hose and hose assemblies in sizes larger than 2 in (50.8 mm) are not intended for use on reels. 1.2 This standard d
22、oes not apply to: a) Flexible hose connectors for LP-Gas that are investigated under the Standard for Pigtails and Flexible Hose Connectors for LP-Gas, UL 569; b) Gas appliance connectors for handling fuel gases at 5 psig (34.5 kPa) or less, which are investigated under Connectors for Gas Appliances
23、, ANSI Z21.24, nor to metallic hose intended for use in oil transportation piping, in petroleum renery piping, or in gas transmission and distribution piping systems; or c) Hose intended for use in automotive applications or hose intended for use in conned areas. d) Hose assemblies that are investig
24、ated under Gas Hose Connectors for Portable Outdoor Gas-Fired Appliances, ANSI Z21.54. 2 General 2.1 Units of measurement 2.1.1 If a value for measurement is followed by a value in other units in parentheses, the second value may be only approximate. The rst stated value is the requirement. 2.2 Unda
25、ted references 2.2.1 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. DECEMBER 15, 2014 LP-GAS HOSE - UL 21 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR
26、DISTRIBUTION WITHOUT PERMISSION FROM UL CONSTRUCTION 3 Tube and Cover 3.1 The tube or lining of a hose shall be made from an elastomeric material such as synthetic rubber, thermoplastic, or thermoplastic elastomer of the oil-resistant type. For hose up to and including the 2-in (50.8 mm) size, a sim
27、ilar elastomeric 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, an elastomeric cover shall be employed. A tube or a cover shall be smooth, of uniform thickness, free from defects in workmanship, and fr
28、ee 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. Exception: In the case of a coextruded multilayer tube or cover, the entire tube or cover will be use
29、d in all applicable tests, rather than the individual layers. 4 Reinforcement 4.1 A reinforcement shall be provided and shall be of cotton, synthetic bers, or corrosion-resistant material such as stainless steel, or any combination thereof, evenly and rmly applied over the tube. The ply or plies sha
30、ll be impregnated with a rubber compound which shall cause the plies to adhere rmly to each other and to the tube and cover. 5 Inside Diameter 5.1 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
31、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, or a set of wood or metal plug gauges, straight or ball type, in increments no greater than 0.01 in (0.3 mm) for hoses in sizes 1
32、in (25.4 mm) and less and 0.02 in (0.5 mm) for hoses in sizes greater than 1 in (25.4) 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 pl
33、ug gauge is used, the plug gauge is to be inserted in the hose sample until a close t 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 gauge
34、s is used, the diameter of the gauge, which when inserted in the hose sample gives a close t without forcing, is to be recorded as the internal diameter of the hose. If the end of a wire-braided hose is constricted or ared, the inside diameter is to be measured far enough from the end to be represen
35、tative of the inside diameter by means of an expanding ball gauge. DECEMBER 15, 2014 LP-GAS HOSE - UL 21 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 6 Thickness of Tube or Cover 6.1 The thickness of a tube, and of a cover if one is used
36、, shall not be less than 0.047 in (1.19 mm). 6.2 A power-driven buffing machine (grinding wheel) or skiving machine outlined in the Practice for Rubber-Preparation of Product Pieces for Test Purposes from Products, ASTM D3183, is to be used for removing irregularities in specimens. The abrasive whee
37、l of a buffing machine is to be No. 30 to 60 grit; and the diameter and rotary velocity of the wheel are to be such that it will have a peripheral speed of 4000 700 ft per min (20.3 3.6 m/s). The machine is to be provided with a slow feed to avoid overheating of the specimen. 6.3 A dial micrometer g
38、raduated to 0.001 in (0.025 mm) which exerts a load of 80 85 g by means of a weight is to be used. The load is to be applied through a at contact foot 0.25 0.01 in (6.4 0.25 mm) in diameter. 6.4 One piece, about68i n(150 200 mm) in length, taken from the sample selected for physical and detail tests
39、, is to be used in determining the thickness of the lining and cover in accordance with the following. 6.5 A strip, about68i n(150 200 mm) in length and 1 in (25.4 mm) in width, or as close to a 1-in width as possible from small diameter hose, is to be cut from the hose, and the rubber part separate
40、d from the plies. In case the thickness of the part is not uniform around the circumference of the hose, the strip is to be cut from the thinnest portion of the sample. 6.6 The strip specimen is to be buffed or skived to remove the impressions left by the fabric or braid or other surface irregularit
41、ies, using the buffing or skiving machine described in 6.2. A series of ve thickness measurements are to be taken within the area from which the impressions have been removed, and the maximum reading obtained is to be taken as the thickness of the rubber part. 7 Assembly Couplings 7.1 Each end of an
42、 assembly shall be provided with a metal-connecting coupling consistent with the service for which the connector is designed. 7.2 Aluminum shall not be used in combination with copper or copper alloy. 7.3 A part made of drawn-brass or machined from brass rod, containing more than 15 percent zinc sha
43、ll withstand, without cracking, the Moist Ammonia-Air Stress Cracking Test, Section 20. 7.4 End-connecting couplings shall be of corrosion-resistant metal or of steel provided with a protective coating having corrosion-resistant qualities at least equivalent to those of the coatings specied in 7.5.
44、7.5 Cadmium plating shall not be less than 0.0003 in (0.008 mm) thick, and zinc plating shall not be less than 0.0005 in (0.013 mm) thick. However, on parts where threads constitute the major portion of the area, the cadmium or zinc plating shall not be less than 0.00015 in (0.0038 mm) thick. DECEMB
45、ER 15, 2014 LP-GAS HOSE - UL 21 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 7.6 A standard LP-Gas cylinder valve connecting tting shall comply with the Standard for Compressed-Gas Cylinder Valve Outlet and Inlet Connections, ANSI/CGA V-
46、1. 7.7 A compression-type tubing tting shall not be used when it utilizes a slip-on ring or sleeve or a tting requiring the use of a gasket to obtain a gas-tight joint. Exception: This requirement is not applicable when a gas-tight joint can be obtained without the use of seal material as in the cas
47、e of a gasket or an O-ring used as a secondary seal. 7.8 Pipe threads shall be in accordance with the Standard for Pipe Threads, General Purpose (Inch), ANSI/ASME B1.20.1. 7.9 A hose assembly shall not be constructed with end ttings that are capable of connecting an appliance with a female CGA 600 c
48、onnection to a LP-Gas cylinder larger than 2-1/2 pound (1 kg) water capacity. PERFORMANCE 8 Proof-Pressure Test 8.1 General 8.1.1 A hose shall withstand a hydrostatic pressure of 700 psig (4830 kPa) for 5 min without leakage, ballooning, or rupture. 8.2 Apparatus 8.2.1 Hydrostatic pressure may be ap
49、plied by means of a hand- or power-operated pump or an accumulator system capable of increasing the pressure in the hose at a rate of not less than 300 psig (2070 kPa) nor more than 1000 psig (6900 kPa) per minute. A calibrated pressure-indicating device is to be connected in the piping system. The pressure-indicating device shall comply with one of the following: a) An analog gauge having a pressure range of at least 150 percent of the anticipated maximum working pressure; b) A d
