All new and some existing gas installations where modifications or new equipment is being installed must have a gas interlocking system to comply with BS6173.

The installation of an interlock gas system will prevent the gas from being turned on until the ventilation system is fully operational. An interlock system uses an air pressure sensor to detect when the ventilation system canopy is operational and working with sufficient air flow to comply with the regulations; once these conditions are met the ventilation system will allow a normally closed gas solenoid valve on the incoming gas supply to open. While the air flow continues to meet the requirements gas equipment can be used normally, if the airflow falls below the required level or the ventilation system is switched off the gas flow will be automatically switched off.

All ventilation systems that we supply and install for commercial kitchens using gas fully comply with BS6173 with all gas components and catering equipment installed by commercially registered Gas Safe Register (previously Corgi) installation engineer.

Where an existing ventilation system is in place the installation of an interlock system would be required by the replacement or retro installation of a Class 2 gas fired appliance, most but not all commercial gas fired prime cooking equipment falls into this category.