1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULDecember 7, 20171UL 1349Outline of Investigation for LP-Gas VaporizersIssue Number: 2DECEMBER 7, 2017Summary of TopicsThis second issue of the Outline of Investigation for LP-Gas Vaporizers,Subje
2、ct 1349, which covers requirements for stationary vaporizers used inLP-Gas systems in accordance with LP-Gas Code, NFPA 58, is beingissued to harmonize UL 1349, Section 4.4, with NFPA 58, Section 5.24.9.4and to update the Moist Ammonia Air Stress Cracking Test.ULs Outlines of Investigation are copyr
3、ighted by UL LLC. Neither a printed norelectronic copy of an Outline of Investigation should be altered in any way. All ofULs Outlines of Investigation and all copyrights, ownerships, and rights regardingthose Outlines of Investigation shall remain the sole and exclusive property of ULLLC.COPYRIGHT
4、2017 UL LLCUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULDECEMBER 7, 2017UL 13492No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONTENTSINTRODUCTION1 Scope .52 Gen
5、eral .52.1 Components .52.2 Units of measurement .52.3 Undated references .63 Glossary 6CONSTRUCTION4 General Requirements All Vaporizers 75 Direct Fired Vaporizers 86 Containers and Piping .97 Materials .9PERFORMANCE8 General .109 Deformation Test 1110 External Leakage Test 1211 Operation Test .121
6、2 Seat Leakage and Endurance Tests 1313 Hydrostatic Pressure Test .1314 Input Test 1415 Temperature Test .1416 Dielectric Voltage Withstand Test .1417 Accelerated Aging Test .1418 LP-Gas Compatibility Test .1419 Low Temperature Test 1520 Moist Ammonia Air Stress Cracking Test 15MANUFACTURING AND PRO
7、DUCTION TESTS21 General 16RATINGS22 Pressure and Temperature .16MARKINGS23 General .16INSTRUCTIONS24 Installation and Operating 17APPENDIX ADECEMBER 7, 2017 UL 1349 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULStandards for ComponentsA1DEC
8、EMBER 7, 2017UL 13494UL COPYRIGHTED MATERIAL NOT 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 f
9、or use, and installation in propane systemsand 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 cove
10、red by this standard shall complywith the requirements 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) Invo
11、lves a feature or characteristic not required in 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 co
12、mponents are incomplete in construction features 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.
13、2.1 Values stated without parentheses are the requirement. Values in parentheses are explanatory orapproximate information.DECEMBER 7, 2017 UL 1349 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL2.3 Undated references2.3.1 Any undated refere
14、nce to a code or standard appearing in the requirements 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 va
15、por pressure notexceeding that allowed for commercial 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 con
16、tainer, that receives LP-Gas in liquidform and adds 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
17、 by directflame impingement onto a heat exchange 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-
18、IMMERSION A type of vaporizer that has an electric 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 applieselec
19、trical energy to an intermediate heat sink.3.8 VAPORIZER, 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
20、liquid LP-Gas. The heating of themedium is at a 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).DECEMBER 7, 2017UL 13496UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCT
21、ION ORDISTRIBUTION WITHOUT PERMISSION FROM ULCONSTRUCTION4 General Requirements All Vaporizers4.1 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 container(s) shall meet therequirement
22、s of 6.1.4.2 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, Division 1 or 2, (or Zone 1 or 2, r
23、espectively),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 standard for the protection tech
24、nique 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 assembly of a direct-fired vaporize
25、r, 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 of an indirect vaporizer, andthe
26、 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 (nonhazardous) locations and foroutdoor
27、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.4.3 LP-Gas vaporizers shall be provided with automatic means to preve
28、nt the passage of the continuousflow of liquid LP-Gas from the vaporizer to its vapor discharge piping.4.4 Each vaporizer shall be equipped with a spring-loaded pressure relief valve that complies with 4.9.The minimum rate of discharge in cubic feet per minute (cfm) air shall be the greater of the t
29、wo methodsof calculation noted in (a) and (b) below:a) Based upon conservative heat transfer calculations by assuming the vaporizing chamber isat its normal maximum liquid level, and the vaporizer is at maximum heating capacity, themaximum vapor generating capacity shall be determined in accordance
30、with the Operation Test,Section 11. This vapor rate shall be converted into an equivalent air capacity rate. Theminimum rate of discharge of 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
31、relief valvecapacity noted in the Standard for Container Assemblies for LP-Gas, UL 644, using a surfacearea that is the sum of the vaporizer container surface and the LP-Gas wetted exterior surface.Exception: Vaporizers of the electric, indirect-fired type, or direct-fired type with container surfac
32、e areasless than 20 ft2may be in accordance with either item (a) or (b).DECEMBER 7, 2017 UL 1349 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL4.5 Fusible plug devices shall not be used as relief devices.4.6 Manual shutoff valves that contr
33、ol the flow of gas to the vaporizer or burner assembly or containershall have a pressure rating in accordance with 22.1 and comply with the Standard 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 Fl
34、ammable Fluids, UL 842.4.7 Solenoid operated shutoff valves shall comply with safety valves in the Standard for ElectricallyOperated Valves, UL 429. If the valves are required to comply with 4.2, they shall also comply with theStandard for Electrically Operated Valves for Use in Hazardous (Classifie
35、d) Locations, UL 1002.4.8 Pressure regulators shall comply with the Standard for LP-Gas Regulators, UL 144.4.9 Relief Valves shall comply with the Standard for Safety Relief Valves for Anhydrous Ammonia andLP-Gas, UL 132. They shall be installed in that portion of the container that communicates wit
36、h vapor.4.10 Tubing fittings, if used, shall comply with gas fittings as described in the Standard for Tube Fittingsfor Flammable and Combustible Fluids, Refrigeration Service, and Marine Use, UL 109.5 Direct Fired Vaporizers5.1 In addition to the requirements of General Requirements All Vaporizers,
37、 Section 4, direct-firedvaporizers shall comply with this section.5.2 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).5.3 A means for manually turning off the gas to the main burner and pilot shall be provided and sh
38、allcomply with 4.6.5.4 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
39、 have a temperature or pressure limitcontrol that meets the intent of 5.6.5.5 If the pilot flow exceeds 2000 Btu/hr (2 MJ/hr), the safety control shall also shut off the flow of gas tothe pilot.5.6 Direct-fired vaporizers shall be equipped with a control in accordance with 5.7 to prevent the heating
40、system from raising 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.5.7 Pressure o
41、r liquid level 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.DECEMBER 7
42、, 2017UL 13498UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM UL6 Containers and Piping6.1 Containers that are part of a vaporizer assembly shall be constructed in accordance with the ASMEBoiler and Pressure Vessel Code, Section I, Rules for Con
43、struction of Power Boilers, and bear the codesymbol “S”, or Section VIII, Division I, Rules for Construction of Pressure Vessels and bear the codesymbol “U”. In either case the MAWP of the containers shall be in accordance with 22.1.Exception: Containers that are excluded from the ASME Code due to s
44、ize are not required to complywith 6.1.6.2 Containers that comply with the Exception to 6.1 shall meet the requirements of the External Leakageand Hydrostatic Pressure Tests, Sections 10 and 13 respectively.6.3 Material specifications for piping shall comply with 7.2. Pipe sections shall comply with
45、 therequirements of the Deformation Test, Section 9, if incorporating female threaded sections, the ExternalLeakage Test, Section 10, and the Hydrostatic Pressure Test, Section 13. Flexible hose connectors shallnot be used in the vaporizer assembly.7 Materials7.1 LP-Gas-confining or operating parts
46、of a vaporizer shall have the strength and durability to providereliable service of the parts and of the assembly.7.2 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-confi
47、ning or operatingparts of vaporizers. This does not prohibit the use of nodular iron.7.3 A part in contact with LP-Gas shall be resistant to the action of such fluid.7.4 With reference to the requirement in 7.3, elastomeric materials such as valve disc or soft seat, a sealring, a diaphragm, or a gas
48、ket shall be subjected to:a) The Accelerated Aging Test, Section 17;b) The LP-Gas Compatibility Test, Section 18; andc) The Low Temperature Test, Section 19.Polymeric materials that are part of a component and which are exposed to LP-Gas shall be subjected tothe Accelerated Aging Test, Section 17 an
49、d the LP-Gas Compatibility Test, Section 18.Exception: Acetal polymers, chlorotrifluorethylene polymers, tetrafluorethylene, fluorinated ethylenepropylene polymers and polyamides of composition polyhexamethylene adipamide or polycaproamidepolymers (nylon 6, 6/6 or 6/16) shall only be subjected to the Accelerated Aging Test, Section 17.7.5 A brazing material used for joining pressure-confining parts of an assembly shall have a melting point(solidus temperature) of no less than 1,000F (538C). This requirement is not meant to prohibit thewelding of aluminum.DE
