Gas Pipe Blanking from Meter

A blank makes sense when you do not want to rip out the pipework straight away, or cannot. The pipe stays in the walls or on the outside wall, it is safely sealed, and after an inspection it can be used again in the future. Removing everything is permanent and takes longer. It usually also means building work afterwards, such as filling chases in the walls and sealing holes where the pipe passed through.

Blanking can be permanent or temporary. A temporary blank is common during a renovation when the gas will be reconnected later. Even a temporary blank must be completely gas-tight and recorded in the paperwork. Before gas is turned back on, the system needs a new inspection and a tightness test.

Why bother if the valve is already closed? Old valves and seals lose their tightness over time. A forgotten pipe in a cellar or under a floor can be drilled into or damaged during later building work. An open or poorly sealed pipe end is a hidden risk that may only show itself years later.

The work on the pipe itself is quick. The paperwork takes longer and should happen in the right order:

• End your gas supply contract with your energy supplier, otherwise you may keep paying standing charges without using any gas
• Ask the gas network operator or meter operator to remove the meter, because the meter belongs to them and their own technician takes it out
• Check with them exactly where the supply should be capped and what documents they expect from you afterwards
• In a block of flats, speak to the building management or owners' association first, because risers and parts of the pipework are shared
• If the whole service pipe to the building is being taken out of use, ask your local building authority whether this needs any approval

Rules on permits differ from country to country and sometimes between regions. Whether a simple notification is enough or a formal procedure is needed depends on the scope of the work. If the job goes beyond capping pipework inside the house, check directly with the local building authority rather than relying on a neighbour or a forum post.

Blanking must only be done by a qualified, registered gas engineer. A homeowner or a general plumber without gas registration must not work on gas pipework. In most countries this is a legal requirement, not just advice. A registered engineer usually works like this:

1. Inspect the installation and locate the main gas valve, the meter position and the route of the pipework.
2. Close the main gas valve and confirm that gas is really not flowing.
3. Release the pressure in the pipe and safely vent any remaining gas.
4. Prepare the pipe end: clean it, cut it back if needed, and prepare the thread or flange.
5. Fit a blank, plug or cap that suits the pipe material and diameter.
6. Carry out a tightness test, usually under slight pressure with a pressure gauge, backed up by a gas detector or leak detection spray on the joints.
7. Write a report describing the work done and the test result.

Where exactly will the blank go? That depends on the situation. The network operator usually wants the supply sealed at the boundary of their network, that is at the main valve where the service pipe enters the property. If only part of the pipework in the house is being taken out of use, for example the branch to a cooker, only that branch is capped and the rest stays in service. The service pipe and any work on the gas network itself are handled by the network operator, not by a private gas engineer.

On ordinary, easily accessible pipework the work on site usually takes a few hours. If the house had a gas boiler, the engineer will often disconnect it from the gas and make it safe at the same visit.

The amount of work, and therefore the final cost, varies from house to house. The job is simpler when you have:

• Pipework that is easy to reach near the valve or in a meter box on the outside wall
• Newer steel pipework with good threads, or copper pipe
• Existing drawings or records, and a meter already removed by the network operator

The job takes longer or gets more complicated with:

• Old corroded pipes, where a section has to be replaced before a blank can be fitted at all
• Pipework hidden in walls, floors or service shafts that has to be opened up first
• Capping in several places, for example with several appliances or in a block of flats
• Missing records and an unknown pipe route
• Underground pipework or an unclear boundary between the service pipe and the house installation

For unusual cases the engineer will usually come for a site visit first and only then suggest how to proceed.

• Just closing the valve and leaving the pipe as it is, because a valve is not a permanent seal
• Letting someone without gas registration do the job, as your insurer may refuse to pay out after damage and penalties may apply
• Trying to remove the meter yourself, when it belongs to the network or meter operator
• Forgetting to close the account with your supplier, so bills for standing charges keep arriving
• Losing the report that the network operator, a buyer or a future inspector will ask for
• Working on shared pipework in a block of flats without talking to the building management

If you smell gas at any point, do not switch lights or appliances on or off, open the windows, leave the building and call your local gas emergency number or 112.

At handover, ask the engineer to show you where the pipe was capped and to give you the paperwork. Check that you have:

• A blank or cap firmly fitted, with no signs of leaking and a clearly visible point of work
• The main valve closed and the pipework labelled as out of service
• A report with the property details, the date, a description of how and where the pipe was sealed
• The result of the tightness test recorded, including the method used
• The engineer's name, signature and registration number, or the company stamp
• An inspection certificate if the network operator, your insurer or a buyer requires one
• All documents filed with the house records for the long term