From network to property: services and responsibility

Before you work on any gas installation, you need to know whose pipe you're touching. The gas in a home passes through parts owned and looked after by different people, and the law sets out a clear point where the gas network stops and the consumer's installation begins.

From the main to the appliance

Following the gas from the street to the appliance:

1. The distribution main runs under the street. It belongs to the gas transporter (GT), a company licensed by Ofgem to carry gas through its network.
2. The service pipe branches off the main and brings gas into the property. In law, it runs from the main to the outlet of the first emergency control.
3. The emergency control valve (ECV) is the consumer's valve for shutting off the gas in an emergency. Its outlet is where the network ends.
4. The primary meter installation: the meter regulator, the meter and the fittings that connect them.
5. The installation pipework runs from the meter to each appliance, including the appliance isolation valves.

IGEM/G/1 sets out these boundaries so that every party knows exactly where their responsibility starts and stops. Where a GT fits an excess flow valve or thermal cut-off directly on the ECV outlet (sometimes done in blocks of flats), that fitting counts as part of the ECV, and the network ends at its outlet.

Who is responsible for what

BS 6400-1 shows the split of responsibility in a typical domestic installation:

The other parties you'll hear about:

• The gas supplier sells the gas to the consumer through the primary meter. Faults with the meter, and suspected tampering, are reported to the supplier.
• The meter asset manager works for the supplier or meter owner. It makes sure meter installations are designed, fitted, maintained and removed by suitably qualified people.
• The consumer is the person who uses the gas.

The primary meter installation's own boundaries are set in IGEM/G/1. It begins at the outlet of the first valve that all its gas passes through (in a home, the ECV), and it ends at the meter's outlet connection or outlet adaptor. On a semi-concealed meter box with a flexible connection after the meter, it ends at the box's outlet adaptor.

Duties when gas escapes

Because the network belongs to the transporter, so do some legal duties for escapes. Under the Gas Safety (Management) Regulations:

• There's a single, continuously staffed emergency phone number for reporting escapes from the network or from any gas fitting it supplies. That's the National Gas Emergency Service on 0800 111 999.
• For an escape on the network, the company conveying gas in that part of the network must attend as soon as reasonably practicable, and stop the escape within 12 hours of being told about it.
• For an escape from a gas fitting in a property (for example the installation pipework), the same duty falls on whoever conveys gas in the network immediately upstream of that fitting's emergency control.
• The responsible person for the premises must have the gas shut off straight away if they know or suspect gas is escaping. If gas still escapes, or the smell persists, they must report it at once. The supply mustn't be turned back on, except to repair it, until the escape has been dealt with.

What you do on site when you find an escape is covered in 14.1 Gas escapes.

The transporter must also tell you the operating pressure at the outlet of the service pipe if you ask for it before working on a gas fitting.

Older and unusual arrangements

Some older installations don't follow the standard arrangement. For example, part of the meter installation may sit upstream of the valve that acts as the ECV, or a pipe owned by someone else may run between the ECV and the meter. Responsibility then varies from site to site, and needs to be agreed and recorded.

One old arrangement is no longer acceptable: a sub-deduct arrangement, set up before March 1996, where part of the gas supplied to one premises is piped on to supply other premises. IGEM/G/1 requires these to be reported to the gas transporter, who agrees with the consumer how to remove them.

Sources: IGEM/G/1 Ed. 3 4.1.1–4.1.6network, ECV, AECV, meter installation IGEM/G/1 Ed. 3 6.2, 6.4.1standard and legacy arrangements IGEM/G/1 Ed. 3 Section 5; IGEM/G/4 Ed. 2parties GSIUR 1998 reg. 2(1)service pipe, supplier GS(M)R 1996 regs 6(8), 7escapes, pressure information IGEM/G/11 Ed. 2 3.4emergency service BS 6400-1:2016 Figure 1, 6.1.2, 6.5responsibilities, insulation joint IGEM/G/1 Ed. 3 Section 5, 6.4.2sub-deduct

▸Tutor notes

• Draw the supply from the main to an appliance and have learners mark the end of the network, the start and end of the meter installation, and who is responsible for each part.
• Ask: if gas is escaping from the service pipe outside, who must stop it, and within how long? What about a leaking joint on the installation pipework?
• GS(M)R is quoted here from the 1996 Regulations as originally made, which name British Gas as the operator of the emergency phone line. IGEM/G/11 Ed. 2 3.4 describes the current position: gas transporters run the 24/7 emergency service and the 0800 111 999 number.
• CCN1 §9 also assesses multi-occupancy arrangements (external and internal risers, remote meters). These need IGEM/G/5, which hasn't been reviewed for this course yet.