ANSI/NSF 14-2003 Plastics Piping System Components and Related Materials (i4)
ISO 23550:2011 Safety and control devices for gas burners and gas-burning appliances - General requirements
ISO 23551-9:2015 history
2022ISO 23551-9:2022 Safety and control devices for gas burners and gas-burning appliances — Particular requirements — Part 9: Mechanical gas thermostats
2015ISO 23551-9:2015 Safety and control devices for gas burners and gas-burning appliances - Particular requirements - Part 9: Mechanical gas thermostats