1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 252A Compressed Gas Regulator AccessoriesUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR
2、FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Compressed Gas Regulator Accessories, UL 252A Fourth Edition, Dated September 16, 2010 Summary of Topics This revision of ANSI/UL 252A is being issued to reaffirm approval as an American National Standard. No
3、changes in requirements are involved. Text that has been changed in any manner or impacted by ULs electronic publishing system is marked with a vertical line in the margin. The revisions are substantially in accordance with Proposal(s) on this subject dated November 14, 2014. All rights reserved. No
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8、hasers computer system. The requirements in this Standard are now in effect, except for those paragraphs, sections, tables, gures, 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
9、revised and that have a future effective date are located after the Standard, and are preceded by a SUPERSEDED REQUIREMENTS notice. JANUARY 16, 2015 UL 252A tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JANUARY 16, 2015 UL 252A tr2 No T
10、ext on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL SEPTEMBER 16, 2010 (Title Page Reprinted: January 16, 2015) 1 UL 252A Standard for Compressed Gas Regulator Accessories First Edition July, 1991 Second Edition June, 1996 Third
11、Edition November, 2003 Fourth Edition September 16, 2010 This ANSI/UL Standard for Safety consists of the Fourth Edition including revisions through January 16, 2015. The most recent designation of ANSI/UL 252A as a Reaffirmed American National Standard (ANS) occurred on January 16, 2015. ANSI appro
12、val for a standard does not include the Cover Page, Transmittal Pages, Title Page, or effective date information. The Department of Defense (DoD) has adopted UL 252A on August 12, 2002. The publication of revised pages or a new edition of this Standard will not invalidate the DoD adoption. Comments
13、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 http:/. ULs Standards for Safety are copyrighted by UL. Neither a printed nor electronic
14、 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 the sole and exclusive property of UL. COPYRIGHT 2015 UNDERWRITERS LABORATORIES INC. ANSI/UL 252A-2010 (R2015)UL COPYRIGHTED MATERIAL NOT AUTHORIZE
15、D FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL SEPTEMBER 16, 2010 COMPRESSED GAS REGULATOR ACCESSORIES - UL 252A 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .4 2
16、Components 4 3 Units of Measurement .5 4 Glossary .5 CONSTRUCTION 5 Assembly 6 6 Materials .6 7 Connections 7 PERFORMANCE 8 General 7 9 Torque Test 8 10 External Leakage Test 9 11 Hydrostatic Strength Test 10 12 Excess Pressure Test .10 13 Volume Change and Weight Loss Tests .11 13.1 General .11 13.
17、2 Tests using n-Hexane and IRM 903 Oil .12 13.3 Tests using liquid MPS 13 14 Accelerated Aging Test for Elastomers 13 15 Comparative Corrosion Test .14 15.1 General .14 15.2 Tests in the presence of salt spray (fog) 14 15.3 Tests in the presence of moist hydrogen sulde-air mixture .14 15.4 Tests in
18、the presence of moist sulfur dioxide-carbon dioxide-air mixture .15 16 Accelerated Aging Test for Nonmetallic Tubes of Flow Meters .15 17 Endurance Test for Valves .15 18 Seat Leakage Test 16 19 Start-to-Discharge and Burst Test .16 MANUFACTURING AND PRODUCTION TESTS 20 General 17 MARKINGS 21 Genera
19、l 17 SEPTEMBER 16, 2010 COMPRESSED GAS REGULATOR ACCESSORIES - UL 252A 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL INTRODUCTION 1 Scope 1.1 These requirements cover accessories intended for direct connection to the low or delivery press
20、ure side of compressed gas regulators. These devices are not intended for direct connection to high or storage cylinder pressures. 1.2 Accessories covered by these requirements are intended for use with compressed gases such as air, carbon dioxide, inert gases, fuel gases, nitrogen, nitrous oxide an
21、d oxygen. 1.3 The suitability of an accessory in combination with a compressed gas regulator shall be judged under the applicable requirements of the Standard for Compressed Gas Regulators, UL 252. 1.4 These requirements do not cover: a) Flow characteristics, b) The physiological effects of accessor
22、ies to be used with medical gases, c) Accuracy of pressure gauges and ow indicators, nor d) Accessories that are covered by other UL standards. 2 Components 2.1 Except as indicated in 2.2, a component of a product covered by this standard shall comply with the requirements for that component. 2.2 A
23、component is not required to comply with a specic requirement that: a) Involves a feature or characteristic not required in the application of the component in the product covered by this standard, or b) Is superseded by a requirement in this standard. 2.3 A component shall be used in accordance wit
24、h its rating established for the intended conditions of use. 2.4 Specic components are incomplete in construction features or restricted in performance capabilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specied limits, and sha
25、ll be used only under those specic conditions. SEPTEMBER 16, 2010 COMPRESSED GAS REGULATOR ACCESSORIES - UL 252A 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3 Units of Measurement 3.1 Values stated without parentheses are the requiremen
26、t. Values in parentheses are explanatory or approximate information. 4 Glossary 4.1 For the purpose of this standard, the following denitions apply. 4.2 FLOW INDICATORS a) Flow Gauges Gauges used to indicate gas ow rates, calibrated to a xed orice outlet with a variable source pressure. b) Flowmeter
27、s A ow tube and oat used to indicate gas ow rate calibrated to a xed source pressure with a variable orice. 4.3 FUEL GAS Acetylene, hydrogen, natural gas, LP-Gas, methylacetylene-propadiene stabilized, and other liqueed and nonliqueed ammable gases that are stable because of their composition or bec
28、ause of the conditions of storage. 4.4 INERT GAS Helium, neon, argon, krypton, xenon, and radon are evaluated as inert gases. 4.5 PRESSURE GAUGES Gauges used to indicate gas pressure, mechanism used of the elastic element type. 4.6 REGULATOR CLASS Denes the maximum end use pressure for the product b
29、ased on the gas pressure or the CGA connection provided on the compressed gas regulator to which the accessory is intended to be installed. See Table 4.1. Table 4.1 Regulator classes Class Test pressure, Denition Psi (MPa) I 200 1.38 Station type regulator II 375 2.59 LP-Gas or MPS regulator III 500
30、 3.45 CGA Nos. 160, 165, 182, 200, 240, 280, 285, 300, 410, 415, 440, 450, 510, 520, 600, 668, 678, 679 IV 1800 12.41 Carbon dioxide regulator V 3000 20.68 CGA Nos. 110, 170, 180, 280, 296, 320, 326, 330, 346, 350, 500, 540, 555, 580, 590, 660, 670, 705 VI 4000 27.58 CGA No. 577 VII 5500 37.92 CGA N
31、os. 347, 680, 695, 701 4.7 REMOVABLE Capable of being removed using a screwdriver, wrench, or similar hand-tool and an opening created by the removal is to be capable of being plugged using are ttings or pipe plugs. 4.8 RUPTURE A fracture in an external component of the product. SEPTEMBER 16, 2010 C
32、OMPRESSED GAS REGULATOR ACCESSORIES - UL 252A 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL CONSTRUCTION 5 Assembly 5.1 An accessory shall include all of the components required for its intended operation and installation, and shall be as
33、sembled as a single unit. 5.2 An accessory intended to be repaired shall be constructed so that parts are capable of being reassembled after being dismantled, to the extent required for routine maintenance. 5.3 A seat disc shall be attached to its poppet or holder, or otherwise assembled to prevent
34、it from becoming dislocated under service conditions. The means to secure the disc shall not rely on cement or adhesive. 5.4 A shut-off valve shall not be equipped with a means to prevent it from closing completely. 6 Materials 6.1 A material in contact with the gas to be handled shall be resistant
35、to the action of such gas. 6.2 With reference to the requirement in 6.1, chlorotriuoroethylene polymers, tetrauoroethylene, and uorinated ethylene propylene polymers are capable of being used with oxygen. 6.3 Unalloyed copper or a copper alloy exceeding 67 percent copper shall not be used for parts
36、in contact with acetylene or methylacetylene-propadiene stabilized (MPS). Exception: Alloys used for bourdon tubes of gauges and inlet lters shall not contain more than 95 percent copper. 6.4 Nonductile cast iron (regular gray iron) shall not be used for bodies or enclosures for LP-Gas valves. This
37、does not preclude the use of malleable or nodular iron. 6.5 When atmospheric corrosion of a part interferes with the intended function of an accessory, the part shall be of a corrosion-resistant material, such as stainless steel or brass, or be provided with a corrosion-resistant protective coating.
38、 6.6 A protective coating shall provide resistance against corrosion to a degree not less than that provided by the coatings specied in 6.7. See the Comparative Corrosion Test, Section 15. 6.7 Zinc plating shall not be less than 0.0005 inch (0.013 mm) thick, except on parts where threads constitute
39、the major portion of the area, in which case the zinc plating shall not be less than 0.00015 inch (0.0038 mm) thick. 6.8 Cadmium plating shall not be used. 6.9 Metal combinations susceptible to galvanic corrosion shall not be used if such corrosion adversely affects the intended operation or strengt
40、h of an accessory. SEPTEMBER 16, 2010 COMPRESSED GAS REGULATOR ACCESSORIES - UL 252A 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 6.10 Thread-sealing compounds and lubricants shall be compatible with the gas to which they are intended to
41、 be exposed to in service. 7 Connections 7.1 Pipe threads shall be in accordance with the Standard for Pipe Threads, General Purpose (Inch), ANSI/ASME B1.20.1; the Standard for Dryseal Pipe Threads (Inch), ANSI/ASME B1.20.3; or the Standard for Dryseal Pipe Threads (Metric Translation of B1.20.3-197
42、6), ANSI/ASME B1.20.4. Exception: Pipe threads complying with a national pipe thread standard compatible with those ttings. 7.2 Outlet hose connections, when used, shall be provided with right-hand threads for nonfuel gases and with left-hand threads for fuel gases, complying with the Standard Conne
43、ctions for Regulator Outlets, Torches and Fitting Hose for Welding and Cutting Equipment, CGA E-1. Exception No. 1: The outlet connection of a compressed gas regulator accessory for use with carbon-dioxide or inert gases is permitted to be a slip-on hose connector of the serrated stem type. Exceptio
44、n No. 2: The outlet connection complies with the requirements of a national pipe thread standard compatible with those ttings. PERFORMANCE 8 General 8.1 Representative samples of an accessory shall comply with the applicable performance requirements indicated in Table 8.1. Table 8.1 Required tests T
45、ests Pressure gauges Flow indicators Flow indicators with metering or shut-off valves Valves Shut-off valves Relief devices Torque Test, Section 9 X X X X X X External Leakage Test, Section 10 XXXXXX Hydrostatic Strength Test, Section 11 XXXXX Excess Pressure Test, Section 12 XXXXXX Volume Change an
46、d Weight Loss Tests, Section 13 XXXXXX Accelerated Aging Test for Elastomers, Section 14 XXXXXX Comparative Corrosion Test, Section 15 XXXXXX Accelerated Aging Test for Nonmetallic Tubes of Flow Meters, Section 16 XX SEPTEMBER 16, 2010 COMPRESSED GAS REGULATOR ACCESSORIES - UL 252A 7 Table 8.1 Conti
47、nued on Next PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL Table 8.1 Continued Tests Pressure gauges Flow indicators Flow indicators with metering or shut-off valves Valves Shut-off valves Relief devices Endurance Test for Valves, Sect
48、ion 17 XXX Seat Leakage Test, Section 18 XX Start-to-Discharge and Burst Test, Section 19 X NOTE An X indicates test is to be performed. 8.2 Additional samples of parts constructed of nonmetallic materials, such as valve seats and O rings are required for the tests specied in the Volume Change and W
49、eight Loss Tests, Section 13, and the Accelerated Aging Test for Elastomers, Section 14. 8.3 Test pressures for the External Leakage Test, Section 10; the Hydrostatic Strength Test, Section 11; and the Endurance Test for Valves, Section 17, are to be based on the manufacturers maximum rated operating pressure for the product. 9 Torque Test 9.1 Joints in a compressed gas regulator accessory shall not leak, nor shall there be evidence of loosening, distortion, or other damage re
