NSF 5-2016 Water Heaters Hot Water Supply Boilers and Heat Recovery Equipment.pdf

1、NSF International Standard / American National StandardNSF/ANSI 5 - 2016 Water Heaters, Hot Water SupplyBoilers, and Heat Recovery EquipmentNSF International, an independent, not-for-profit, non-governmental organization, is dedicated to being the leading global provider of public health and safety-

2、based risk management solutions while serving the interests of all stakeholders This Standard is subject to revision. Contact NSF to confirm this revision is current. Users of this Standard may request clarifications and interpretations, or propose revisions by contacting: Chair, Joint Committee on

3、Food Equipment c/o NSF International 789 Dixboro Road, P.O. Box 130140 Ann Arbor, Michigan 48113-0140 USA Phone: (734) 769-8010 Telex: 753215 NSF INTL FAX: (734) 769-0109 E-mail: infonsf.org Web: http:/www.nsf.org i NSF International Standard/ American National Standard for Food Equipment Water heat

4、ers, hot water supply boilers, and heat recovery equipment Standard Developer NSF International NSF International Board of Directors Designated as an ANSI Standard January 28, 2016 American National Standards Institute ii Prepared by The NSF Joint Committee on Food Equipment Recommended for Adoption

5、 by The NSF Council of Public Health Consultants Adopted by The NSF Board of Directors January 1959 Revised May 1972 Revised December 1980 Revised November 1983 Revised November 1992 Revised July 2000 Revised September 2005 Revised April 2007 Revised April 2009 Revised August 2012 Revised January 20

6、16 Published by NSF International PO Box 130140, Ann Arbor, Michigan 48113-0140, USA For ordering copies or for making inquiries with regard to this Standard, please reference the designation “NSF/ANSI 5-2016.” Copyright 2016 NSF International Previous editions 2012, 2009, 2007, 2005, 2000, 1992, 19

7、83, 1980, 1972, 1959 Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from NSF International. Printed in the United States of America. iii D

8、isclaimers1NSF International (NSF), in performing its functions in accordance with its objectives, does not assume or undertake to discharge any responsibility of the manufacturer or any other party. The opinions and findings of NSF represent its professional judgment. NSF shall not be responsible t

9、o anyone for the use of or reli-ance upon this Standard by anyone. NSF shall not incur any obligation or liability for damages, including consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon this Standard. NSF Standards provide basic criteria to pr

10、omote sanitation and protection of the public health. Provisions for mechanical and electrical safety have not been included in this Standard because governmental agen-cies or other national standards-setting organizations provide these requirements. Participation in NSFs Standards development activ

11、ities by regulatory agency representatives (federal, lo-cal, state) shall not constitute their agencys endorsement of NSF or any of its Standards. Preference is given to the use of performance criteria measurable by examination or testing in NSF Stand-ards development when such performance criteria

12、may reasonably be used in lieu of design, materials, or construction criteria. The illustrations, if provided, are intended to assist in understanding their adjacent standard requirements. However, the illustrations may not include all requirements for a specific product or unit, nor do they show th

13、e only method of fabricating such arrangements. Such partial drawings shall not be used to justify im-proper or incomplete design and construction. Unless otherwise referenced, the annexes are not considered an integral part of NSF Standards. The an-nexes are provided as general guidelines to the ma

14、nufacturer, regulatory agency, user, or certifying organ-ization. 1The information contained in this Disclaimer is not part of this American National Standard (ANS) and has not been processed in accordance with ANSIs requirements for an ANS. Therefore, this Disclaimer may contain material that has n

15、ot been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the Standard. This page is intentionally left blank. v Contents 1 General . 1 1.1 Purpose 1 1.2 Scope . 1 1.3 Alternate materials, design, and construction 1 1.4 Meas

16、urement . 1 2 Normative references . 1 3 Definitions . 2 4 Materials . 2 4.1 Conformance with NSF/ANSI 51 . 2 4.2 External surfaces . 2 4.3 Intermediate transfer media . 2 5 Design and construction . 2 5.1 General sanitation 2 5.2 Equipment mounting 3 5.3 Legs and feet . 3 5.4 Temperature regulators

17、 3 5.5 Recirculation systems 3 5.6 Backflow and cross-connection protection . 3 5.7 Louvers 4 6 Performance . 4 6.1 Temperature regulation 4 7 Product Literature . 5 8 Installation, operation, and maintenance instructions 5 Annex A . A1 A.1 General A1 A.2 Qualifications of installer A1 A.3 Location

18、and piping A1 A.4 Water piping materials . A1 A.5 Water supply lines A2 A.6 Water supply pressure control . A2 A.7 Dual heater installations . A2 A.8 Booster pumps . A2 A.9 Safety measures A2 A.10 General purpose water A3 A.11 Recirculation by gravity . A3 A.12 Recirculation by pump . A3 A.13 Insula

19、tion . A3 A.14 Testing . A3 Annex B . B1 B.1 Sizing water heaters for dishwashing machines B1 B.2 Storage type water heaters B2 This page is intentionally left blank. vii Foreword2The purpose of this Standard is to establish minimum food protection and sanitation requirements for the materials, desi

20、gn, construction, and performance of water heaters, hot water supply boilers, and heat recovery equipment. This edition of the Standard contains numerous editorial and format changes intended to promote uniform interpretation of the Standard. Many changes reflect an effort to achieve consistency wit

21、h other NSF Food Equipment Standards. The style and format of this Standard have been modified for consistency with the guidelines published by the American National Standards Institute. This edition of the Standard contains the following revision: Issue 6: This revision eliminated redundancy and po

22、tential conflicts with the U.S. Department of Energy (DOE) Rules and Regulations and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHAE) requirements. This Standard was developed by the NSF Joint Committee on Food Equipment using the consensus process described by t

23、he American National Standards Institute. Suggestions for improvement of this Standard are welcome. Comments should be sent to Chair, Joint Committee on Food Equipment at standardsnsf.org, or c/o NSF International, Standards Department, P.O. Box 130140, Ann Arbor, Michigan, 48113-0140. 2The informat

24、ion contained in this Foreword is not part of this American National Standard (ANS) and has not been processed in accordance with ANSIs requirements for an ANS. Therefore, this Foreword may contain material that has not been subjected to public review or a consensus process. In addition, it does not

25、 contain requirements necessary for conformance to the Standard. This page is intentionally left blank. 1 2016 NSF NSF/ANSI 5 2016 NSF/ANSI Standard for Food Equipment Water heaters, hot water supply boilers, and heat recovery equipment 1 General 1.1 Purpose This Standard establishes minimum public

26、health and sanitation requirements for the materials, design, construction, and performance of commercial water heaters, hot water supply boilers, and heat recovery equipment. This Standard does not contain safety requirements. 1.2 Scope This Standard contains requirements for heat recovery equipmen

27、t and equipment intended to provide hot water heated by electricity, gas, steam, or oil. The types of equipment covered by this Standard include, but are not limited to: automatic storage water heaters, circulating water heaters, hot water supply boilers, and steam heat exchangers. Instantaneous wat

28、er heaters used to heat water other than for beverages are covered under this Standard. Boilers used for space heating are not covered under this Standard. Materials and components covered under other NSF or ANSI Standards or Criteria shall also comply with the requirements therein. This Standard is

29、 not intended to restrict new design, provided that such design meets the minimum specifications described herein. 1.3 Alternate materials, design, and construction While specific materials, design, and construction may be stipulated in this Standard, equipment that incorporates alternative material

30、s, design, and construction may be acceptable when such equipment meets the intent of applicable requirements herein. 1.4 Measurement Decimal and SI conversions provided parenthetically shall be considered equivalent. Metric conversions and significant figure rounding have been made according to IEE

31、E/ASTM SI 10. 2 Normative references The following documents contain provisions that, through reference, constitute provisions of this NSF/ANSI Standard. At the time this Standard was balloted, the editions listed below were valid. All documents are subject to revision, and parties are encouraged to

32、 investigate the possibility of applying the most recent edition of the documents indicated below. The most recent published edition of the document shall be used for undated references. NSF 2016 NSF/ANSI 5 2016 2 ANSI/ASME B40.100 2005. Pressure Gauges and Gauge Attachments3IEEE/ASTM SI 10 2010. Am

33、erican National Standard for Metric Practice4NSF/ANSI 51. Food equipment materials NSF/ANSI 170. Glossary of food equipment terminology 3 Definitions Terms used in this Standard that have special technical meaning are defined in NSF/ANSI 170. 4 Materials The requirements contained in this clause are

34、 intended to protect water from contamination and ensure that the materials used in the construction of water heaters, hot water supply boilers, and heat recovery equipment resist wear, penetration by vermin, and the effects of cleaning compounds and other substances that may contact the materials i

35、n the intended end-use environment. Materials used in unexposed non-food zone areas shall be exempt from all requirements in 4. 4.1 Conformance with NSF/ANSI 51 Materials shall conform to the requirements in NSF/ANSI 51 applicable to the zone in which the material is used. 4.2 External surfaces Exte

36、rnal surfaces shall be corrosion resistant or rendered corrosion resistant. Materials not in contact with potable water shall conform to the nonfood zone requirements in NSF/ANSI 51. 4.3 Intermediate transfer media 4.3.1 Intermediate transfer media shall not directly contact potable water. 4.3.2 Whe

37、n supplied by the manufacturer, intermediate transfer media used in a single-wall heat exchanger shall meet the material formulation requirements for food zone materials in NSF/ANSI 51. 5 Design and construction This section contains design and construction requirements for equipment covered within

38、the scope of this Standard. 5.1 General sanitation 5.1.1 Water heaters, hot water supply boilers, and heat recovery equipment shall be designed and manufactured to prevent the harborage of vermin and the accumulation of dirt and debris, and to permit the inspection, maintenance, servicing, and clean

39、ing of the equipment and its components. 3 ASME International, Three Park Avenue, New York, NY 10016-5990 . 4ASTM International, 100 Barr Harbor Dr., West Conshohocken, PA 19428 . NSF 2016 NSF/ANSI 5 2016 3 5.1.2 External surfaces shall be easily cleanable. 5.2 Equipment mounting 5.2.1 Water heaters

40、 and heat recovery equipment shall be: designed to be sealed to a floor, raised base, counter, or shelf, and fabricated so that seepage cannot accumulate under the unit; or elevated on legs to provide a minimum clearance of 6 in (153 mm) beneath the unit. 5.2.2 Necessary piping (including piping inl

41、ets and outlets), gas burner enclosures, and service connections (for water supply, electrical, steam, or gas service) may be present in the clearance space provided that there is a minimum of 4 in (102 mm) of unobstructed space beneath the unit. NOTE Where practical, service connections should be l

42、ocated so that horizontal pipes, conduits, and wires can be installed with a minimum clearance of 6 in (153 mm) above the floor. 5.3 Legs and feet 5.3.1 Legs and feet shall be fastened to the body of the machine and shaped at their floor or counter contacts to minimize the accumulation of dirt and t

43、he harborage of vermin. 5.3.2 Legs and feet shall be sufficiently rigid to support the equipment with a minimum of cross bracing. 5.3.3 If the outer dimension of a leg exceeds the outer dimension of its foot by in (0.50 in, 13 mm) or more in the same plane, then the foot shall extend at least 1.0 in

44、 (25 mm) below the leg at the minimum adjustment (see figure 1a). 5.3.4 Hollow sections between leg and foot shall be closed. Legs and feet shall have no exposed threads at the maximum adjustment. 5.3.5 Gussets shall be assembled to the equipment and shall be easily cleanable and designed to prevent

45、 vermin harborage. The resultant assembly shall have no recessed areas (see figure 1b). 5.4 Temperature regulators Water heating equipment shall have a thermostatic control with a maximum differential of 15 F (9 C). This ensures that the thermostat actuates at an incoming water temperature of not gr

46、eater than 15 F (9 C) below the outlet temperature. 5.5 Recirculation systems Recirculation systems shall be designed to recirculate water through the heater and maintain the required temperature in the hot water supply line. If the recirculating system is supplied by the manufacturer, the manufactu

47、rer shall provide guidelines for acceptable method(s) of installation and recirculation. 5.6 Backflow and cross-connection protection 5.6.1 Heat recovery equipment Heat recovery equipment shall be manufactured to prevent a cross connection with the potable water system or a backflow into the potable

48、 water system when there is a failure of a single barrier system. NSF 2016 NSF/ANSI 5 2016 4 5.6.2 Single wall heat exchangers 5.6.2.1 The pressure of the heat transfer medium in a single wall heat exchanger shall be less than the intended minimum operating pressure of the potable water system. Sing

49、le wall heat exchangers shall have one or more devices capable of automatically maintaining the pressure of the heat transfer medium entering the unit at a level less than the pressure of the potable water exiting the unit. 5.6.2.2 Single wall heat exchangers shall have a permanently affixed label identifying the intermediate transfer media, which must be used with the unit. The intermediate transfer media shall conform to the requirements in 4.3. When intermediate transfer media is not supplied by the manufacturer, a permanently affixed label shal