1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL 732 Oil-Fired Storage Tank Water Heaters STANDARD FOR SAFETYUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM ULUL COPYRIGHTED MATERIAL
2、NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL UL Standard for Safety for Oil-Fired Storage Tank Water Heaters, UL 732 Sixth Edition, Dated January 31, 2018 Summary of Topics This New Edition of ANSI/UL 732 is being issued to address the editorial maintenance of U
3、L Standards for Safety. 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. UL provides this Standard as is without warr
4、anty of any kind, either expressed or implied, including but not limited to, the implied warranties of merchantability or tness for any purpose. In no event will UL be liable for any special, incidental, consequential, indirect or similar damages, including loss of prots, lost savings, loss of data,
5、 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
6、 of the claim. Users 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 judgment (including reasonable attorneys fees) resulting from any error or deviation introduced while purchase
7、r is storing an electronic Standard on the purchasers computer system. JANUARY 31, 2018 UL 732 tr1UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JANUARY 31, 2018 UL 732 tr2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURT
8、HER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JANUARY 31, 2018 1 UL 732 Standard for Oil-Fired Storage Tank Water Heaters The rst through third editions were titled Oil-Fired Water Heaters. First Edition July, 1955 Second Edition June, 1969 Third Edition June, 1974 Fourth Edition Febru
9、ary, 1988 Fifth Edition September, 1995 Sixth Edition January 31, 2018 This ANSI/UL Standard for Safety consists of the Sixth Edition. The most recent designation of ANSI/UL 732 as a Reaffirmed American National Standard (ANS) occurred on July 12, 2013. ANSI approval for a standard does not include
10、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-Line Collaborative Standards Development System (CSDS) at https:/. ULs Standards for S
11、afety 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 the sole and exclusive property of UL. COPYRIGHT 2018 UNDERWRITERS LABORATORIES INC. A
12、NSI/UL 732-1997 (R2013)UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL JANUARY 31, 2018 OIL-FIRED STORAGE TANK WATER HEATERS - UL 732 2 No Text on This PageUL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHO
13、UT PERMISSION FROM UL CONTENTS INTRODUCTION 1 Scope .5 2 Glossary .5 3 Units of Measurement .8 4 Components8 CONSTRUCTION 5 Assembly 8 6 Accessibility for Servicing 9 7 Base .10 8 Casing10 9 Radiation Shields 10 10 Insulation Materials .11 11 Combustion Chamber .11 12 Heating Surface Joints 11 13Baf
14、fles.12 14 Flue Collars 12 15 Damper and Draft Regulator .12 16 Materials Contacting Water 12 17 Water-Storage Vessels 13 18 Dip Tubes .14 19 Controls .14 19.1 Application 14 19.2 Limit control .15 19.3 Water-temperature regulating control .16 20 Field Wiring 16 21 Internal Wiring19 22 Separation of
15、 Circuits .23 23 Bonding for Grounding 24 ELECTRICAL COMPONENTS 24 General27 25 Mounting of Electrical Components .27 26 Electrical Enclosures 28 27 Accessibility of Uninsulated Live Parts, Film-Coated Wire and Moving Parts .33 28 Motors and Motor Protection .38 29 Switches and Controllers 42 30 Cap
16、acitors .43 31 Electrical Insulating Material43 32 Spacings High-Voltage Circuits .44 33 Spacings Low-Voltage Circuits45 34 Protection of Users and Service Personnel 45 PERFORMANCE 35 General49 36 Test Installation for Other Than Alcove-or Closet-Installed Heaters .50 JANUARY 31, 2018 OIL-FIRED STOR
17、AGE TANK WATER HEATERS - UL 732 3UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 36.1 Enclosure .50 36.2 Chimney connector .51 37 Test Installation for Alcove-or Closet-Installed Units .54 37.1 Enclosure .54 37.2 Chimney connector .57 38 Ins
18、trumentation .60 38.1 Draft measurement .60 38.2 Fuel-input measurement 60 38.3 Power measurement60 38.4 Speed measurement .61 38.5 Temperature measurement 61 39 Initial Test Conditions .63 39.1 General .63 39.2 Heater equipped with mechanical atomizing burner.64 39.3 Heater equipped with vaporizing
19、 burner .64 40 Combustion Test Burner and Water Heater 65 41 Water-Temperature Control Test65 42 Limit-Control Cutout Test 66 43 Temperature Test.66 44 Seepage and Burnoff Test Vaporizing Burner 70 45 Hydrostatic Test on Water-Storage Vessels 71 46 Short-Circuit Test .71 47 Dielectric Voltage-Withst
20、and Test .73 48 Torque Test on Screws and Bolts.74 49 Securement Tests on Constant-Level Valve Assemblies .75 50 Bonding-Conductor Test .75 51 Strain-Relief Test .75 52 Nonmetallic Dip Tube Tests 76 52.1 Deformation and weight loss.76 52.2 Resistance to crushing 76 52.3 Collapse 79 MANUFACTURING AND
21、 PRODUCTION TESTS 53 General80 MARKING 54 General81 INSTALLATION INSTRUCTIONS 55 General83 APPENDIX A Standards for Components .A1 JANUARY 31, 2018 OIL-FIRED STORAGE TANK WATER HEATERS - UL 732 4UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM U
22、L INTRODUCTION 1 Scope 1.1 These requirements cover oil-red storage-tank water-heating appliances having a fuel input of not more than 200,000 Btu per hour (60 kW). These requirements do not apply to heaters that include storage vessels having a water capacity of more than 120 gallons (454.2 liters)
23、, or that are intended for heating water to a temperature of more than 200F (93.3C). 1.2 The oil-burning equipment covered by these requirements are intended for installation in accordance with the National Fire Protection Association Standard for the Installation of Oil Burning Equipment, NFPA 31,
24、the International Mechanical Code and the Uniform Mechanical Code. 2 Glossary 2.1 For the purpose of this standard the following denitions apply. 2.2 ANTIFLOODING DEVICE A primary safety control that causes the fuel ow to be shut off upon a rise in fuel level or upon receiving excess fuel, and that
25、operates before discharge of fuel can occur. 2.3 APPLIANCE FLUE The ue passages within the appliance. 2.4 AUTOMATICALLY LIGHTED APPLIANCE An appliance in which fuel to the main burner is turned on and ignited automatically. 2.5 BAFFLE An object placed in an appliance to direct the ow of air or ue ga
26、ses. 2.6 BURNER A device for the nal conveyance of fuel or a mixture of fuel and air to the combustion zone. 2.7 BURNER, MECHANICAL-ATOMIZING A power operated burner that prepares and delivers the fuel and all or part of the air by mechanical process in controllable quantities for combustion. Some e
27、xamples are air atomizing, high- and low-pressure atomizing, horizontal and vertical rotary atomizing, and vertical rotary wall-ame burners. 2.8 BURNER, MECHANICAL-DRAFT A burner that includes a power driven fan, blower, or other mechanism as the principal means for supplying air for combustion. 2.9
28、 BURNER, NATURAL-DRAFT A burner that principally depends upon the natural draft created in the ue to induce into the burner the air required for combustion. 2.10 BURNER, VAPORIZING A burner consisting of an oil-vaporizing bowl or other receptacle to which liquid fuel may be fed in controllable quant
29、ities; the heat of combustion is used to vaporize the fuel, with provision for admitting air and mixing it with the fuel vapor in combustible proportions. 2.11 CASING An enclosure forming the outside of the appliance, no parts of which are likely to be subjected to intense heat. JANUARY 31, 2018 OIL
30、-FIRED STORAGE TANK WATER HEATERS - UL 732 5UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 2.12 CHIMNEY CONNECTOR The pipe that connects a solid or liquid fuel-burning appliance to a chimney. 2.13 COMBUSTIBLE MATERIAL Combustible material a
31、s pertaining to materials adjacent to or in contact with heat-producing appliances, chimney connectors and vent connectors, steam and hot-water pipes,andwarm-airductsmeansmaterialmadeoforsurfacedwithwood,compressedpaper,plantbers, or other material that will ignite and burn. Such material shall be c
32、onsidered as combustible even though ameproofed, re-retardant treated, or plastered. 2.14 COMBUSTION The rapid oxidation of fuel accompanied by the production of heat, or heat and light. 2.15 COMBUSTION CHAMBER The portion of an appliance within which combustion occurs. 2.16 COMBUSTION (FLAME) SAFEG
33、UARD A safety combustion control. 2.17 CONSTANT-LEVEL VALVE A device that maintains a constant level of fuel oil in a reservoir for delivery to the burner. 2.18 CONTROL A device intended to regulate the fuel, air, water, or electrical supply to the controlled equipment. It may be automatic, semiauto
34、matic, or manual. 2.19 CONTROL, LIMIT An automatic safety control responsive to changes in liquid level, pressure, or temperature; for limiting the operation of the controlled equipment. 2.20 CONTROL, SAFETY An automatic control including a relay, switch, or other auxiliary equipment used in conjunc
35、tion therewith to form a safety control system that is intended to reduce the likelihood of operation of the controlled equipment that would result in a risk of re or injury to persons. 2.21 CONTROL, PRIMARY-SAFETY An automatic safety control intended to reduce the likelihood of abnormal discharge o
36、f fuel at the burner in case of ignition failure or ame failure. 2.22 CONTROL, SAFETY-COMBUSTION A primary-safety control responsive directly to ame properties; sensing the presence of ame and causing fuel to be shut off in event of ame failure. 2.23 DRAFT REGULATOR A device that functions to mainta
37、in a desired draft in the appliance by automatically reducing the chimney draft to the desired value. 2.24 ELECTRICAL CIRCUITS: a) High-Voltage Circuit A circuit involving a potential of not more than 600 volts and having circuit characteristics in excess of those of a low-voltage circuit. b) Low-Vo
38、ltage Circuit A circuit involving a potential of not more than 30 volts rms alternating- current (42.4 volts peak or direct current) and supplied by: 1) A primary battery; 2) A Class 2 transformer; or 3) A combination of transformer and xed impedance that, as a unit, complies with all the performanc
39、e requirements for a Class 2 transformer. JANUARY 31, 2018 OIL-FIRED STORAGE TANK WATER HEATERS - UL 732 6UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL A circuit derived from a high-voltage circuit, by connecting resistance in series with
40、the supply circuit as a means of limiting the voltage and current is not considered to be a low-voltage circuit. c) Safety-Control Circuit A circuit involving one or more safety controls. 2.25 FLUE COLLAR That portion of an appliance constructed for attachment of the chimney or vent connector. 2.26
41、FLUE GASES Combustion products and excess air. 2.27 FUEL OIL Any hydrocarbon oil dened by Standard Specications for Fuel Oils, ASTM D396-1992. 2.28 HEATING SURFACE A surface that transmits heat directly from ame or ue gases to the medium to be heated. 2.29 INDIRECT-FIRED APPLIANCE An appliance const
42、ructed so that combustion products or ue gases are not mixed in the appliance with the medium to be heated; hence is provided with a ue collar. 2.30 MAINTENANCE The periodic tasks usually performed to operate and maintain an appliance, such as air, fuel, pressure, and temperature regulation, cleanin
43、g, lubrication, resetting of controls, and the like. Repair and replacement of parts other than those expected to be renewed periodically is not considered to be maintenance. Some examples of maintenance are: a) Cleaning or replacing nozzles, atomizers, and pilots. b) Setting ignition electrodes. c)
44、 Cleaning strainers or replacing strainer or lter element. d) Resetting safety control. e) Replacing igniter cable. JANUARY 31, 2018 OIL-FIRED STORAGE TANK WATER HEATERS - UL 732 7UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION OR DISTRIBUTION WITHOUT PERMISSION FROM UL 3 Units of Me
45、asurement 3.1 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. 4 Components 4.1 Except as indicated in 4.2, a component of a product covered by this standard shall comply with the requi
46、rements for that component. See Appendix A for a list of standards covering components generally used in the products covered by this standard. 4.2 A component is not required to comply with a specic requirement that: a) Involves a feature or characteristic not required in the application of the com
47、ponent in the product covered by this standard, or b) Is superseded by a requirement in this standard. 4.3 A component shall be used in accordance with its rating established for the intended conditions of use. 4.4 Specic components are incomplete in construction features or restricted in performanc
48、e capabilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specied limits, and shall be used only under those specic conditions. CONSTRUCTION 5 Assembly 5.1 An oil-red water heater shall be factory built as a single complete assembl
49、y or a group of subassemblies and shall include all of the essential components necessary for its function when installed as intended. An oil-red water heater may be shipped as two or more major subassemblies. 5.2 An oil-red storage-type water heater may be furnished as two major subassemblies, each factory built to accommodate the other. The assembly formed when the two subassemblies are joined shall comply with the requiremen
