Gas emergency control valve (ECV): meter and regulator rules

The core question: in an emergency, can somebody who is not you turn the gas off quickly?

The emergency control valve

The ECV shuts off the whole installation, not a single appliance. It sits at the installation inlet, normally close to the meter on its supply side. It must be:

• Readily accessible. In a gas escape or fire the occupier must reach it at once, without moving furniture or hunting for tools.
• Hand-operable. It has a securely attached handle, marked to show open and shut, and needs no supplier-held key or tool. A lever that moves up and down is shut when fully down, a quarter turn from open, so a lever that drops falls shut.
• Backed by a notice. A notice on or near the primary meter tells the consumer what to do in a gas escape. Where the control is away from the meter, the notice goes at the control. It says to shut off the supply if gas escapes, to call 0800 111 999 for natural gas (or the LPG supplier) if it keeps escaping, and not to turn the gas back on until a competent person has stopped the escape. It also gives the emergency contact and the date it was first displayed.

The meter regulator

The regulator reduces the incoming service pressure to the operating pressure the installation needs and holds it steady. It cannot boost pressure, and emergency isolation is the ECV’s job, not the regulator’s. It must stay accessible so it can be checked, and so the transporter, or someone it authorises, can adjust or replace it.

• Only the transporter, or someone acting for them, may break the seal on a primary meter regulator supplied from a main.
• An appliance's own regulator is different: the engineer setting up the appliance may break its seal, and must reseal it as soon as practicable (regulation 14).
• Where the normal pressure at the regulator inlet is 75 mbar or more, a second automatic device must protect downstream fittings if the regulator fails (regulation 14(1)).

Siting the meter

A domestic meter installation must be readily accessible for reading, maintenance and emergency isolation, protected from mechanical damage and excessive heat, and not in an unventilated enclosure. A shorter pipe run, tidiness or shelter never overrides those three.

• Its site must not adversely affect the means of escape from the premises in a fire (regulation 12(1)). A meter in a building's only stairway out puts escape most at risk.
• Keep it clear of damage from electrical apparatus.
• An external meter box or compound lets escaping gas disperse to open air, not into the building or wall cavity. Store nothing readily combustible in it, and give the consumer a labelled key if it locks.
• If the meter's bosses or side pipes are held on by soldered joints alone, do not connect rigid pipe to it (regulation 12(5)), because rigid pipe passes settlement, thermal movement and knocks to those joints.

Boxing in a meter without ventilation or access hinders inspection and emergency operation, and traps any small escape.

• In a building with two or more floors above the ground floor, a new meter should not go on or under a stairway, or in any other part, that is the only way out in a fire.
• In other buildings, and for a replacement meter, keep off such a route where you reasonably can. If a meter has to go there, use a fire-resistant meter, a fire-resistant compartment with self-closing doors, or a thermal cut-off just upstream of the meter or its regulator that shuts off the gas above 95 °C.

Notices and diagrams

• Meter away from its valve. If a meter is installed or moved more than 2 m from the nearest upstream emergency control, or out of sight of it, a permanent notice on or near the meter must say where that control is before gas is first supplied through it (regulation 15(2)).
• Secondary meters. Where a primary meter feeds secondary meters, such as one per bedsit, a permanent line diagram of the meters, installation pipework and emergency controls goes on or near the primary meter and every emergency control connected to it, updated whenever the layout changes (regulation 17).
• Several primary meters on one service. A notice on or near each primary meter says so.
• No prepayment primary meter feeding secondary meters. If its credit ran out, every downstream consumer would lose gas at once, and turning it back on could release gas from appliances left on (regulation 16(1)). The ban covers smart meters in prepayment mode.
• Notice to the transporter. The gas transporter, which normally owns the service pipe, needs at least 48 hours' notice before work on it, including connecting or disconnecting a meter.

When a meter is removed

If a primary meter is removed and not refitted at once (regulation 16(3)):

1. Close any service valve that controlled that meter and no other.
2. Seal the outlet of the emergency control with an appropriate fitting.
3. Clearly mark any live gas pipe as containing gas, so nobody cuts into it thinking it is dead.

With no such service valve, and no meter refitted within 12 months, the service is disconnected as near the main as is reasonably practicable.