ISO INTERNATIONAL STANDARD 23550 Third edition 2018-04 Safety and control devices for gas and/or oil burners and appliances General requirements Dispositifs de commande et de seécurite pour bruleurs a gaz et appareilsagaz-Exigencesgénérales Reference number IS0 23550:2018(E) [so @ IS0 2018 IS0 23550:2018(E) Contents Page Foreword vi Introduction.. ...vii 1 Scope. 2 Normative references. .. 1 3 Terms and definitions . 2 4 Classification ... 5 4.1 Classes of control. 4.2 Groups of controls.. 5 4.3 Types of DC supplied controls. 5 4.4 Classes of control functions : 5 Test conditions and tolerances.. 5.1 Test conditions.. 6 5.2 Tolerances.. 6 6 Construction.. 6.1 General. 6.2 Construction requirements.. 6.2.1 Appearance.. 6.2.2 Holes.. 6.2.3 Breather holes... 6.2.4 Vent limiter.. 8 6.2.5 Screwed fastenings 6.2.6 Moving parts. 6.2.7 Sealing caps ... 6.2.8 Disassembling and assembling for servicing and/or adjustment for controls. 10 6.2.9 Auxiliary channels and orifices.. 10 6.2.10 Pre-setting device .. 10 6.3 Materials. 11 6.3.1 General material requirements.. 11 6.3.2 Housing ar 11 6.3.3 Springs providing closing force and sealing force. 12 6.3.4 Resistancetocorrosionandsurfaceprotection.. 12 6.3.5 Impregnation 12 6.3.6 Seals for glands for moving parts. 13 6.3.7 Jointing 13 6.4 Connections . 13 6.4.1 General. .13 6.4.2 Connection sizes. 13 6.4.3 Connection types. 14 6.4.4 Threads. 15 6.4.5 Union joints 16 6.4.6 Flanges. 16 6.4.7 Compression fittings... 16 6.4.8 Flare connections ... 17 6.4.9 Nipples for pressure tests. 17 6.4.10 Strainers. 17 6.4.11 Gas connections by GQC 18 6.5 Gas controls employing with electrical components in the gas way. 18 6.5.1 General. .18 6.5.2 Requirements 18 6.5.3 Ignition trial test. 18 6.5.4 Test of ignition source 19 7 Performance 20 @ IS0 2018 - All rights reserved ili IS0 23550:2018(E) 7.1 General.. .20 7.2 Leak-tightness. 7.2.1 General. ..21 7.2.2 Requirements 7.2.3 Test. 21 7.3 Torsion and bending .24 7.3.1 General.. .24 7.3.2 Torsion. m24 7.3.3 Bending moment. .24 7.3.4 Torsion and bending tests... .24 7.4 Rated flow rate.. 7.4.1 General. ..28 7.4.2 Requirements. 7.4.3 Test.. 28 7.5 Durability. .30 7.5.1 Elastomers in contact with gas 7.5.2 Resistance of elastomers to lubricants and gases. 30 7.5.3 Marking resistance. 7.5.4 Resistance to scratching. 31 7.5.5 Resistance to humidity.. .32 7.6 Functional requirements. .33 7.7 Endurance, 7.8 Vibration test. .33 8 Electrical equipment 33 8.1 General... 8.2 Requirements.. .33 8.3 Test.. 8.4 Protection by enclosure 34 Electromagnetic compatibility (EMC) ..34 6 9.1 Protection against environmental influences . .34 9.1.1 General. .34 9.1.2 Requirements . 9.1.3 Test.. .35 9.2 Harmonics and interharmonics including mains signalling at a.c. power port, low frequency immunity. ..35 9.2.1 General. ..35 9.2.2 Requirements. ..35 9.2.3 Test.. 35 9.3 Voltage dips, voltage interruptions and voltage variations in the power supply network 35 9.3.1 Voltage dips and voltage interruptions ... 35 9.3.2 Test.... 35 9.3.3 Voltage variation ..36 9.4 Test of influence of voltage unbalance. .36 9.5 Surge immunity tests.. .36 9.5.1 General. ..36 9.5.2 Requirements . 9.5.3 Test.. 37 9.6 Electrical fast transient/burst .37 9.6.1 General. ..37 9.6.2 Requirements. 9.6.3 Test. 37 9.7 Ring wave immunity .37 9.7.1 General.. .37 9.7.2 Requirements . .37 9.7.3 Test.. 37 9.8 Electrostatic discharge. .37 9.8.1 General.... iy @ IS0 2018 - All rights reserved