Emergency control valves
Position, operation, access and labelling of the ECV, and what to do when it's wrong.
This topic supports
- M04.2Locate and operate an emergency control valve and describe its labelling and access requirements.
Draft: this lesson hasn't yet been technically reviewed.
The (ECV) is the one gas valve the law expects every consumer to be able to find and use. If someone smells gas, it's how they turn the supply off. That only works if it's in the right place, easy to reach, and obvious which way is off.
What the ECV is
GSIUR defines an emergency control as a valve for shutting off the gas in an emergency, intended for use by a consumer of gas. IGEM/G/1 adds that the ECV:
- is a single point of isolation, shutting off the flow of gas in all circumstances
- marks the end of the network: its outlet is where the gas transporter's responsibility stops (see 4.1)
- must be on the premises and accessible to the consumers there, to count as being for their use.
No one may turn on a new gas supply to premises unless there's a properly sited emergency control with adequate access (GSIUR reg. 9(1)).
Where it should be
The HSE guidance to GSIUR expects that:
- every individual premises using gas (each house, flat, maisonette or caravan) has its own emergency control, whether or not it has a meter
- it is as near as reasonably practicable to where the gas supply enters the premises
- it is readily accessible to everyone who uses gas there, so not in a basement or cellar
- it is protected against tampering. If it's in a locked compartment, the occupiers must have keys. A valve in a normally locked meter room, which only a landlord, supplier or the emergency services can get into, can't be the emergency control.
Where there's a meter, the meter control can serve as the emergency control. Where premises include separate buildings under one person's control (a house with stables, say), one emergency control can be enough.
Whoever turns the gas on to the premises should make sure every consumer knows where their emergency control is and what to do in a gas emergency. In rented property, the landlord or managing agent should tell every tenant, including new ones.
How it operates
A valve operated by a hand-wheel must show which way opens and which way closes. On a new meter installation, BS 6400-1 has the installer check that the ECV meets these rules, is rated for the supply pressure, and is accessible. If it isn't, they advise the gas transporter, who is responsible for it.
Notices
Every primary meter must have a permanent emergency notice on or near it, telling the consumer what to do if gas escapes (GSIUR reg. 15(1)). Where the ECV is next to the meter, that notice does the job.
Where the ECV is not next to the meter, or there's no meter, a permanent notice reading "Gas emergency control" must be displayed on or near the valve. The HSE guidance says it should tell the consumer to:
- shut off the gas if there's an escape
- if gas keeps escaping, ring the National Gas Emergency Service on 0800 111 999 (for LPG, the supplier's emergency number)
- not turn the gas back on until a competent person has fixed the escape.
It also gives the emergency contact details and the date it was first displayed. If a meter is more than 2 metres from the ECV, or out of sight of it, a notice at the meter must say where the ECV is (GSIUR reg. 15(2)). BS 6400-1 adds that the ECV's on and off positions can be marked with ON/OFF tape.
Additional emergency control valves
An (AECV) is another valve for the consumer to shut off gas in an emergency. It's always downstream of the ECV and doesn't mark the end of the network. It may not isolate the whole installation, and it never replaces the ECV, which is always required.
You'll find AECVs where the ECV is out of the consumer's easy reach. For example, where several flats' meters are grouped together, every flat should have an AECV near where the gas enters it. A secondary meter has an AECV close to its inlet. Fitting AECVs in installation pipework is covered in 5.5.
Two other valves you'll meet:
- A (MIV) sits just upstream of a meter to shut it off. On a medium pressure supply, it's the valve used for tightness testing.
- An inlet isolation valve is fitted upstream of an ECV, to isolate a whole building. It's for authorised people only, not consumers.
When the ECV isn't right
The Unsafe Situations Procedure covers the common problems:
| Situation | Classification | Action |
|---|---|---|
| In an emergency, the ECV is hard to reach, or has no handle | Immediately Dangerous | Turn off all appliances and ring the Gas Emergency Contact Centre |
| Not an emergency, but the ECV is hard to reach or has no handle | At Risk | Tell the responsible person that access to the ECV, and a way to operate it, is a legal requirement. If there's no handle, also notify the Gas Emergency Contact Centre. Turning off won't remove the risk, so don't attach a "Danger Do Not Use" label |
| No AECV where one is needed and the ECV can't be reached | At Risk | Tell the responsible person an AECV is needed |
| The ECV lets by (no smell of gas) | At Risk | Notify the Gas Emergency Contact Centre and make safe |
| An AECV lets by (no smell of gas) | At Risk | Maintain or replace the AECV |
Testing an ECV for let-by is covered in 6.2.
Sources: GSIUR 1998 reg. 2(1)definition IGEM/G/1 Ed. 3 4.1.3, 4.1.4, Section 5ECV, AECV, MIV, IIV GSIUR 1998 reg. 9; HSE L56 paras 150–157siting, operation, notices GSIUR 1998 reg. 15meter notices BS 6400-1:2016 6.4.2, 6.5, 8.2.3.2, 8.3, 11ECV checks, AECVs, notices IGEM/G/11 Ed. 2 Table 1situations 3.3, 3.5–3.9 CCN1 Issue 16 §9assessed
Tutor notes
- On a training rig, have learners find the ECV, show the open and shut positions, and say what marking and notices should be there.
- Give scenarios: a meter in a cellar with the ECV beside it; an ECV in a locked bin store; a meter 4 m from the ECV round a corner. Ask what's wrong, if anything, and what to do.
- CCN1 §9 assesses identifying correctly and incorrectly positioned ECVs, AECVs and MIVs, attaching the right labels, and GSIUR reg. 9(1)–(4).