Meters, Emergency Control Valves and Supply Connections
What the exam tests
Meters, emergency control valves (ECVs) and the supply connection. You should know who owns what, how the ECV must be installed and used, and what an installer may and may not do at the meter.
Core rules
- The meter and service pipe belong to Gas Networks Ireland; the installer must not tamper with, bypass or remove the meter. Work stops at the outlet of the meter/ECV except for the installer's own connection.
- The ECV is the emergency shut-off at the meter outlet. It must be accessible, clearly identified, operate freely and be usable without tools. It is not an appliance isolation valve.
- The meter installation must be ventilated and protected as required; meter boxes must not be blocked or used as storage.
- Main equipotential bonding of the gas installation is required near the meter outlet, in accordance with the electrical regulations; the gas pipe must not be used as an earth electrode.
- A new supply connection is proved for tightness and purged before the meter is connected or the appliance is commissioned.
Worked example
On a pre-connection survey, an installer finds the ECV inside a built-in cupboard with shelves in front of it. The gas supply is live and the customer says the cupboard is only for coats. The installer records the defect and requires the cupboard to be cleared or the ECV made accessible before work proceeds. He does not simply turn the ECV and leave it inaccessible. The reasoning: emergency operation must be possible immediately, not after removing stored items.
Marks-losing traps
Treating the ECV as a service valve for routine isolation; painting over or greasing the ECV; moving the meter to suit a kitchen design; bonding the gas pipe beyond the permitted distance; assuming a meter box is a suitable cupboard.