1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULMay 24, 20071SUBJECT 1349OUTLINE OF INVESTIGATIONFORLP-GAS VAPORIZERSIssue Number: 1MAY 24, 2007Summary of TopicsThis first issue of the Outline of Investigation for LP-Gas Vaporizers,Subject 134
2、9, covers requirements for stationary vaporizers used inLP-Gas systems in accordance with LP-Gas Code, NFPA 58.The UL Foreword is no longer located within the UL Standard. For informationconcerning the use and application of the requirements contained in thisStandard, the current version of the UL F
3、oreword is located onULStandardsInfoNet at: http:/ 2007 UNDERWRITERS LABORATORIES INC.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULMAY 24, 2007SUBJECT 13492No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION
4、ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .42 General .42.1 Components .42.2 Units of measurement .42.3 Undated references .53 Glossary 54 Pressure and Temperature Rating 65 Installation and Operating Instructions .6CONSTRUCTION6 General Requirements All Vaporizers 67 Dire
5、ct Fired Vaporizers 88 Containers and Piping .89 Materials .9PERFORMANCE10 General 1011 Deformation Test .1012 External Leakage Test 1113 Operation Test .1114 Seat Leakage and Endurance Tests 1215 Hydrostatic Pressure Test .1216 Input Test 1317 Temperature Test .1318 Dielectric Voltage Withstand Tes
6、t .1319 Accelerated Aging Test .1320 LP-Gas Compatibility Test .1321 Low Temperature Test 1422 10-Day Moist Ammonia Air Stress Cracking Test 14MANUFACTURING AND PRODUCTION TESTS23 General 15MARKING24 General .15APPENDIX AStandards for ComponentsA1MAY 24, 2007 SUBJECT 1349 3UL COPYRIGHTED MATERIAL NO
7、T AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULINTRODUCTION1 Scope1.1 These requirements cover liquefied petroleum gas (LP-Gas) vaporizers of the stationary type.1.2 Vaporizers covered by these requirements are intended for use, and installation in propane systemsand
8、applications covered by the Liquefied Petroleum Gas Code, NFPA 58, and electrical componentsinstalled in accordance with the National Electrical Code, NFPA 70.2 General2.1 Components2.1.1 Except as indicated in this clause, a component of a product covered by this standard shall complywith the requi
9、rements for that component. See the Standards for Components appendix for a list ofstandards covering components generally used in the products covered by this standard.2.1.2 A component is not required to comply with a specific requirement that:a) Involves a feature or characteristic not required i
10、n the application of the component in theproduct covered by this standard, orb) Is superseded by a requirement in this standard.2.1.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.2.1.4 Specific components are incomplete in construction feature
11、s or restricted in performancecapabilities. Such components are intended for use only under limited conditions, such as certaintemperatures not exceeding specified limits, and shall be used only under those specific conditions.2.2 Units of measurement2.2.1 Values stated without parentheses are the r
12、equirement. Values in parentheses are explanatory orapproximate information.MAY 24, 2007SUBJECT 13494UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL2.3 Undated references2.3.1 Any undated reference to a code or standard appearing in the requi
13、rements of this standard shallbe interpreted as referring to the latest edition of that code or standard.3 Glossary3.1 For the purpose of this outline, the following definitions apply.3.2 LIQUEFIED PETROLEUM GAS (LP-GAS or LPG) Any material having a vapor pressure notexceeding that allowed for comme
14、rcial propane composed predominantly of the following hydrocarbons,either by themselves (excluding propylene) or as mixtures: propane, propylene, butane (normal butaneor iso-butane) and butylenes.3.3 VAPORIZER A piece of equipment, which includes a container, that receives LP-Gas in liquidform and a
15、dds sufficient heat energy to convert the liquid to a gaseous state. They are further classifiedby the type of energy used and how the energy is applied to the LP-Gas.3.4 VAPORIZER, DIRECT-FIRED A type of vaporizer in which the heat energy is furnished by directflame impingement onto a heat exchange
16、 surface in contact with liquid LP-Gas.3.5 VAPORIZER, ELECTRIC A type of vaporizer in which electrical energy is used as a source ofheat. They are further classified by how the electrical energy is applied to the LP-Gas.3.6 VAPORIZER, ELECTRIC, DIRECT-IMMERSION A type of vaporizer that has an electr
17、ic elementimmersed directly into the LP-Gas liquid and vapor.3.7 VAPORIZER, ELECTRIC, INDIRECT An immersion-type vaporizer that has the electric elementimmersed into an interface solution that is in contact with the LP-Gas heat exchanger or applieselectrical energy to an intermediate heat sink.3.8 V
18、APORIZER, INDIRECT (or Indirect-Fired) A vaporizer in which heat energy is furnished bysteam, hot water, the ground, surrounding air, or other heated medium to a vaporizing chamber or totubing, pipe coils, or other heat exchange surface containing the liquid LP-Gas. The heating of themedium is at a
19、point remote from the vaporizer portion containing the LP-Gas. This definition includes adirect-fired water-bath vaporizer (the water bath is the heat transfer medium).MAY 24, 2007 SUBJECT 1349 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL
20、4 Pressure and Temperature Rating4.1 The pressure rating of each type of LP-Gas vaporizer shall not be less than 250 psig (1.725 MPa).4.2 LP-Gas vaporizers covered by these requirements are intended for use at ambient air temperatureswithin the range of minus 40F to plus 130 F (minus 40C to plus 55C
21、).5 Installation and Operating Instructions5.1 A copy of the installation and operating instructions shall be provide with each vaporizer, and it shallbe used as a guide in the examination and testing of the unit.5.2 The instructions shall include operating procedures including maintenance of the va
22、porization rate,pressure and temperature control, specific actions that need to be taken when normal operation isexceeded, and actions needed for emergency shutdown. The instructions shall state that the vaporizer beinstalled in accordance with Liquefied Petroleum Gas Code, NFPA 58, and electrical c
23、omponents installedin accordance with the National Electrical Code, NFPA 70.CONSTRUCTION6 General Requirements All Vaporizers6.1 LP-Gas vaporizers shall include all of the components necessary for its intended function andinstallation, and shall be furnished as a single unit or assembly. The contain
24、er(s) shall meet therequirements of 8.1.6.2 Electrical components, when incorporated into the assembly of a LP-Gas vaporizer, including themeans provided in the assembly for electrical connections, shall comply with the requirements forequipment for use in hazardous locations, Class I, Group D, Divi
25、sion 1 or 2, (or Zone 1 or 2, respectively),as appropriate, in the National Electrical Code, NFPA 70, Articles 500 and 501 (Article 505 for ZoneClassification), depending upon the installation in accordance with Liquefied Petroleum Gas Code, NFPA58. Such components shall comply with the applicable s
26、tandard for the protection technique employed;for example explosion proof equipment shall comply with the Standard for Explosion-Proof andDust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations, UL 1203.Exception No. 1: When electrical components are provided in the asse
27、mbly of a direct-fired vaporizer, orthe direct fired water-bath vaporizer, the above described electrical components need only to comply withthe requirements for ordinary (nonhazardous) locations and for outdoor use locations.Exception No. 2: When electrical components are provided in the assembly o
28、f an indirect vaporizer, andthe electrical components are installed 15 feet (4.5 meters), or more, measured in a horizontal distancefrom any LP-Gas connections or joints in the LP-Gas equipment, the above described electricalcomponents need only to comply with the requirements for ordinary (nonhazar
29、dous) locations and foroutdoor use locations, as appropriate.Exception No. 3: Immersion heating elements for use in direct immersion electric vaporizers need only tocomply with the requirements for ordinary (nonhazardous) locations and for outdoor use locations.MAY 24, 2007SUBJECT 13496UL COPYRIGHTE
30、D MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6.3 LP-Gas vaporizers shall be provided with automatic means to prevent the passage of the continuousflow of liquid LP-Gas from the vaporizer to its vapor discharge piping.6.4 Each vaporizer shall be equipped
31、 with a spring-loaded pressure relief valve that complies with 6.9.The minimum rate of discharge in cubic feet per minute (cfm) air shall be the greater of the two methodsof calculation noted in (a) and (b) below:a) Based upon conservative heat transfer calculations by assuming the vaporizing chambe
32、r isat its normal maximum liquid level, and the vaporizer is at maximum heating capacity, themaximum vapor generating capacity shall be determined in accordance with the Operation Test,Section 13. This vapor rate shall be converted into an equivalent air capacity rate. Theminimum rate of discharge o
33、f the relief valve shall not be less than 150 percent of thisvaporizing capacity.b) The minimum rate of discharge of the relief valve shall not be less than the relief valvecapacity noted in the Standard for Container Assemblies for LP-Gas, UL 644, using a surfacearea that is the sum of the vaporize
34、r container surface and the LP-Gas wetted exterior surface.6.5 Fusible plug devices shall not be used as relief devices.6.6 Manual shutoff valves that control the flow of gas to the vaporizer or burner assembly or containershall have a pressure rating in accordance with 4.1 and comply with the Stand
35、ard for Valves forAnhydrous Ammonia and LP-Gas (Other than Safety Relief), UL 125, or if rated at 1 psig or less, complywith the Standard for Valves for Flammable Fluids, UL 842.6.7 Solenoid operated shutoff valves shall comply with safety valves in the Standard for ElectricallyOperated Valves, UL 4
36、29. If the valves are required to comply with 6.2, they shall also comply with theStandard for Electrically Operated Valves for Use in Hazardous (Classified) Locations, UL 1002.6.8 Pressure regulators shall comply with the Standard for LP-Gas Regulators, UL 144.6.9 Relief Valves shall comply with th
37、e Standard for Safety Relief Valves for Anhydrous Ammonia andLP-Gas, UL 132. They shall be installed in that portion of the container that communicates with vapor.6.10 Tubing fittings, if used, shall comply with gas fittings as described in the Standard for Tube Fittingsfor Flammable and Combustible
38、 Fluids, Refrigeration Service, and Marine Use, UL 109.MAY 24, 2007 SUBJECT 1349 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL7 Direct Fired Vaporizers7.1 In addition to the requirements of General Requirements All Vaporizers, Section 6, d
39、irect-firedvaporizers shall comply with this section.7.2 The relief valve shall be located at the top of the LP-Gas container so as not to be subject totemperatures in excess of 140F (60C).7.3 A means for manually turning off the gas to the main burner and pilot shall be provided and shallcomply wit
40、h 6.6.7.4 Direct-fired vaporizers shall be equipped with a primary safety control that complies with the Standardfor Primary Safety Controls for Gas- and Oil-Fired Appliances, UL 372, to shut off the flow of gas to themain burner if the pilot light is extinguished. This control may also have a tempe
41、rature or pressure limitcontrol that meets the intent of 7.6.7.5 If the pilot flow exceeds 2000 Btu/hr (2 MJ/hr), the safety control shall also shut off the flow of gas tothe pilot.7.6 Direct-fired vaporizers shall be equipped with a control in accordance with 7.7 to prevent the heatingsystem from r
42、aising the LP-Gas pressure above the design pressure rating of the vaporizer equipment,and to prevent raising the pressure within the storage container that supplies the vaporizer above theMAWP of the container. This control can be either pressure or temperature activated.7.7 Pressure or liquid leve
43、l limit controls shall comply with the Standard for Limit Controls, UL 353.Temperature limit controls shall comply with the Standard for Temperature-Indicating and RegulatingEquipment, UL 873, or UL 353, as appropriate. A regulating or operating control meets this requirement.8 Containers and Piping
44、8.1 Containers that are part of a vaporizer assembly shall be constructed in accordance with the ASMEBoiler and Pressure Vessel Code, Section I, Rules for Construction of Power Boilers, and bear the codesymbol “S”, or Section VIII, Division I, Rules for Construction of Pressure Vessels and bear the
45、codesymbol “U”. In either case the MAWP of the containers shall be in accordance with 4.1.Exception: Containers that are excluded from the ASME Code due to size are not required to complywith 8.1.8.2 Containers that comply with the Exception to 8.1 shall meet the requirements of the External Leakage
46、and Hydrostatic Pressure Tests, Sections 12 and 15 respectively.8.3 Material specifications for piping shall comply with 9.2. Pipe sections shall comply with therequirements of the Deformation Test, Section 11, if incorporating female threaded sections, the ExternalLeakage Test, Section 12, and the
47、Hydrostatic Pressure Test, Section 15. Flexible hose connectors shallnot be used in the vaporizer assembly.MAY 24, 2007SUBJECT 13498UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL9 Materials9.1 LP-Gas-confining or operating parts of a vaporiz
48、er shall have the strength and durability to providereliable service of the parts and of the assembly.9.2 Liquid or pressure confining parts shall be made from steel, ductile or malleable iron, brass oraluminum. Non-ductile cast iron (regular gray iron) shall not be used for LP-Gas-confining or oper
49、atingparts of vaporizers. This does not prohibit the use of nodular iron.9.3 A part in contact with LP-Gas shall be resistant to the action of such fluid.9.4 With reference to the requirement in 9.3, elastomeric materials such as valve disc or soft seat, a sealring, a diaphragm, or a gasket shall be subjected to:a) The Accelerated Aging Test, Section 19;b) The LP-Gas Compatibility Test, Section 20; andc) The Low Temperature Test, Section 21.Polymeric materials that are part of a component and which are expo
