1、BSI Standards PublicationBS ISO 23551-9:2015Safety and control devices for gas burners and gas-burning appliancesParticular requirements Part 9: Mechanical gas thermostatsBS ISO 23551-9:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 23551-9:2015. The UK p
2、articipation in its preparation was entrusted to Technical Committee GSE/22, Safety and control devices for gas and oil burners appliances.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary
3、provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015ISBN 978 0 580 87102 3 ICS 27.060.20 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was
4、published under the authority of the Standards Policy and Strategy Committee on 31 August 2015.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 23551-9:2015 ISO 2015Safety and control devices for gas burners and gas-burning appliances Particular requirements Part 9: Mechanical g
5、as thermostatsDispositifs de commande et de scurit pour brleurs fioul et pour appareils fioul - Exigences particulires Partie 9: Thermostats mcaniquesINTERNATIONAL STANDARDISO23551-9First edition2015-08-15Reference numberISO 23551-9:2015(E)BS ISO 23551-9:2015ISO 23551-9:2015(E)ii ISO 2015 All rights
6、 reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an
7、 intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.or
8、gwww.iso.orgBS ISO 23551-9:2015ISO 23551-9:2015(E)Foreword vIntroduction vi1 Scope . 12 Normative references 13 Terms and definitions . 14 Classification 34.1 Classes of controls 34.2 Groups of controls 35 Test conditions . 36 Construction 46.1 General . 46.2 Construction requirements 46.2.1 Appeara
9、nce . 46.2.2 Holes . 46.2.3 Breather holes 46.2.4 Screwed fastenings 46.2.5 Jointing . 46.2.6 Moving parts 46.2.7 Sealing caps 46.2.8 Dismantling and reassembling for servicing and/or adjustment . 46.2.9 Auxiliary channels 46.3 Materials . 56.3.1 General material requirements . 56.3.2 Housing 56.3.3
10、 Springs 56.3.4 Resistance to corrosion and surface protection . 56.3.5 Impregnation 56.3.6 Seals for glands for moving parts 56.4 Gas connections 56.4.1 Making connections 56.4.2 Connection sizes . 56.4.3 Threads 66.4.4 Union joints 66.4.5 Flanges 66.4.6 Compression fittings . 66.4.7 Nipples for pr
11、essure tests 66.4.8 Strainers 67 Performance 77.1 General . 77.2 Leak-tightness 77.2.1 Criteria 77.2.2 Test for leak-tightness . 77.3 Torsion and bending 77.4 Rated flow rate 77.4.1 Criterion 77.4.2 Test for rated flow rate . 87.5 Durability . 87.6 Functional requirements 87.7 Endurance 147.7.1 Mech
12、anical cycling 147.7.2 Thermal cycling15 ISO 2015 All rights reserved iiiContents PageBS ISO 23551-9:2015ISO 23551-9:2015(E)8 EMC/electrical requirements .169 Marking, installation, and operating instructions .169.1 Marking 169.2 Installation and operating instructions 179.3 Warning notice . 17Annex
13、 A (informative) Leak-tightness test Volumetric method .18Annex B (informative) Leak-tightness test Pressure-loss method 19Annex C (normative) Conversion of pressure loss into leakage rate .20Annex D (normative) Test for immunity to power-frequency magnetic fields21Annex E (normative) Specific regio
14、nal requirements in European countries .22Annex F (normative) Specific regional requirements in Canada and USA .23Annex G (normative) Specific regional requirements in Japan .25Bibliography .26iv ISO 2015 All rights reservedBS ISO 23551-9:2015ISO 23551-9:2015(E)ForewordISO (the International Organiz
15、ation for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established
16、 has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.Th
17、e procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the e
18、ditorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent r
19、ights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an ex
20、planation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this do
21、cument is ISO/TC 161, Control and protective devices for gas and/or oil burners and appliances.ISO 23551 consists of the following parts, under the general title Safety and control devices for gas burners and gas-burning appliances Particular requirements : Part 1: Automatic and semi-automatic valve
22、s Part 2: Pressure regulators Part 3: Gas/air ratio controls, pneumatic type Part 4: Valve-proving systems for automatic shut-off valves Part 5: Manual gas valves Part 6: Thermoelectric flame supervision controls Part 8: Multifunctional controls Part 9: Mechanical gas thermostatsAn additional part d
23、ealing with vent valves is planned. ISO 2015 All rights reserved vBS ISO 23551-9:2015ISO 23551-9:2015(E)IntroductionThis part of ISO 23551 is designed to be used in combination with ISO 23550. This part of ISO 23551, together with ISO 23550, establishes the full requirements as they apply to the pro
24、duct covered by this International Standard. This part of ISO 23551 adapts ISO 23550, where needed, by stating “with the following modification”, “with the following addition”, “is replaced by the following”, or “is not applicable” in the corresponding clause. In order to identify specific requireme
25、nts that are particular to this part of ISO 23551 that are not already covered by ISO 23550, this part of ISO 23551 may contain clauses or subclauses that are additional to the structure of ISO 23550. These clauses are numbered starting from 101 or, in the case of an Annex, are designated AA, BB, CC
26、, etc.In an attempt to develop an International Standard, it has been necessary to take into consideration the differing requirements resulting from practical experience and installation practices in various regions of the world and to recognize the variation in basic infrastructure associated with
27、gas and/or oil controls and appliances, some of which are addressed in Annex E to Annex G. This part of ISO 23551 intends to provide a basic framework of requirements that recognize these differences.vi ISO 2015 All rights reservedBS ISO 23551-9:2015Safety and control devices for gas burners and gas
28、-burning appliances Particular requirements Part 9: Mechanical gas thermostats1 ScopeThis part of ISO 23551 specifies safety, constructional, and performance requirements and testing of mechanical gas thermostat for gas burners, gas appliances, and similar use hereafter referred to as “thermostats”.
29、This part of ISO 23551 covers type testing only.This part of ISO 23551 applies to mechanical gas thermostats of nominal connection sizes up to and including DN 50 with declared maximum inlet pressures up to and including 50 kPa for burners and gas-burning appliances using fuel gases as natural gas,
30、manufactured gas, and liquefied petroleum gas (LPG).This part of ISO 23551 applies to mechanical thermostats controlling the gas flow directly or indirectly through an integral gas valve and which do not require external electrical energy for their operation.This part of ISO 23551 only applies to me
31、chanical thermostats used on gas appliances where the thermostat is not directly exposed to the outdoor environment.This part of ISO 23551 only applies to mechanical thermostats which are intended for operating control functions.2 Normative referencesThe following documents, in whole or in part, are
32、 normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 23550:2011, Safety and control devices for gas burner
33、s and gas-burning appliances General requirements3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 23550:2011 and the following apply.3.101mechanical thermostatthermostat which controls the temperature by adjusting the flow rate accordingly to the tempe
34、rature of the thermal sensing element (3.111) without any external energy such that the temperature remains within defined limits3.102adjustable thermostatmechanical thermostat (3.101) in which the temperature set-point (3.115) can be adjusted by the user to anywhere between minimum and maximum valu
35、esINTERNATIONAL STANDARD ISO 23551-9:2015(E) ISO 2015 All rights reserved 1BS ISO 23551-9:2015ISO 23551-9:2015(E)3.103fixed setting thermostatmechanical thermostat (3.101) that has a preset fixed operating temperature which cannot be adjusted by the user3.104snap-acting thermostatmechanical thermost
36、at (3.101) with only two positions for the flow rate, i.e. “full on-off”, “full on-reduced rate”, or “reduced rate-off”3.105modulating thermostatmechanical thermostat (3.101) which controls the flow rate in accordance with a predetermined and continuous function of the temperature of the thermal sen
37、sing element (3.111)3.106modulating thermostat with additional on-off actionmechanical thermostat (3.101) which acts as a snap-acting thermostat (3.104) between the closed and reduced positions and as a modulating thermostat (3.105) between the reduced and full-on positions3.107thermostat closure me
38、mbermovable part of the thermostat which opens and closes the gas way and/or varies the flow rate3.108presetting devicedevice for adjusting an operating condition only by an authorized personNote 1 to entry: It can be fixed or variable (e.g. when it is the gas flow that is adjustable, either an orif
39、ice or an adjusting screw can be used).3.109fixed bypassnon-adjustable presetting device for fixing the minimum gas flow through a thermostat3.110bypass adjusting devicescrew adjustment or an exchangeable orifice that fixes the minimum gas flow rate through the thermostat and which is accessible onl
40、y by the use of tools3.111thermal sensing elementpart of a thermostat which is directly acted upon by temperature changes of the medium to be controlled or to be supervised and which through physical change, thus produced, originates the motion directly or indirectly controlling the action of the cl
41、osure member3.112operating curvegraphical representation of the flow rate as a function of the thermal sensing element temperature at a given temperature set-point (3.115) and at a constant inlet pressure3.113backlashdifference of position of the adjusting knob (3.114) when it is moved in both direc
42、tions to obtain the same flow rate at a constant thermal sensing element temperature3.114adjusting knobspindledialpart of the thermostat which is used to select the temperature set-point (3.115)2 ISO 2015 All rights reservedBS ISO 23551-9:2015ISO 23551-9:2015(E)3.115temperature set-pointany value se
43、lected within the temperature range at which the controlled temperature should be maintained3.116temperature set-point rangerange between the minimum and maximum adjustable temperature set-points (3.115) (by means of the adjusting knob (3.114)3.117calibration flow rateflow rate declared by the manuf
44、acturer for calibration3.118calibration temperature set-pointtemperature at which the calibration flow rate (3.117) should be obtained with the adjustment set to the position and in the direction declared by the manufacturer3.119temperature differential for snap-acting thermostatsdifference in tempe
45、rature necessary to obtain a change in the flow rate at a given set-point3.120deviationmaximum deviation from the temperature set-point (3.115) which is declared by the manufacturer3.121driftpermanent change in the operating curve (3.112) of the thermostat3.122bypasspassage provided in which permits
46、 a flow of gas to the main burner(s) independently of the action of the thermostatic valve3.123calibration reference pointdial setting at which a control is calibrated for agreement between dial indication and sensing element temperature4 Classification4.1 Classes of controlsISO 23550:2011, 4.1 is n
47、ot applicable.4.2 Groups of controlsShall be according to ISO 23550:2011, 4.2.5 Test conditionsShall be according to ISO 23550:2011, Clause 5 with the following addition:Where applicable, the thermostat shall be mounted in an appropriate test fixture and the tests conducted with the thermal sensing
48、element immersed in the intended medium (e.g. water, oil, or air) for the application as specified in the operation and installation instructions. ISO 2015 All rights reserved 3BS ISO 23551-9:2015ISO 23551-9:2015(E)6 ConstructionNOTE Regional specific requirements are given in Annex F.6.1 GeneralSha
49、ll be according to ISO 23550:2011, 6.1.6.2 Construction requirements6.2.1 AppearanceShall be according to ISO 23550:2011, 6.2.1.6.2.2 HolesShall be according to ISO 23550:2011, 6.2.2.6.2.3 Breather holesShall be according to ISO 23550:2011, 6.2.3.6.2.4 Screwed fasteningsShall be according to ISO 23550:2011, 6.2.4.6.2.5 JointingShall be according to ISO 23550:2011, 6.2.5.6.2.6 Moving partsShall be according to ISO 23550:2011, 6.2.6.6.2.7 Sealing capsShall be according to ISO 23550:2011, 6.2.7.6.2.8 Dismantling and reassemblin
