Gas Testing, Purging and Commercial Gas Services in Leeds

What is the difference between testing, purging and commissioning?

The three terms are often used together, but each one is a separate step.

Tightness testing checks that pipework holds pressure and does not leak. It is carried out on new pipework, after alterations, after a reported smell of gas and before a supply is restored.

Purging safely replaces the contents of the pipe. Air is removed and replaced with gas when a system is brought into service. Gas is removed when a system is taken out of service. On larger pipework an inert gas such as nitrogen is used between the two.

Commissioning comes last. Once the pipework is tested and purged, appliances are lit, set up and checked, and the results are recorded.

For commercial and industrial pipework, this work follows IGEM/UP/1 or IGEM/UP/1A, depending on the size of the installation. You can read more on our gas testing and gas purging page.

Commercial gas work across Leeds

The city has a broad mix of property, and the gas work varies with it.

City centre offices and retail

The office district around Wellington Street, Park Row and Whitehall Road has many buildings with rooftop or basement plant. Shopping centres and arcades often have landlord gas supplies feeding several food units.

In multi-let buildings, the first task is usually to establish exactly what each pipe serves before anything is isolated.

South Bank and new development

Large parts of the South Bank and the Aire Valley are being redeveloped. Main contractors and mechanical subcontractors need new installations strength tested, tightness tested, purged and commissioned before handover.

We can work as part of your commissioning programme and provide the test records needed for the building's operation and maintenance file.

Hospitals and universities

The two main hospital sites and the university campuses north of the centre operate large boiler plant with extensive pipework. Work is planned around clinical and teaching needs, often in phases.

Warehousing, food and manufacturing

East and south Leeds, including Cross Green, Stourton, Hunslet and the estates along the M1 and M621, contain distribution centres, food producers and manufacturers. Typical systems include warehouse heaters, process ovens and steam boilers.

We install and maintain commercial heating systems as well as the pipework that supplies them.

Hospitality

Restaurants and bars around Call Lane, Greek Street and Headingley rely on gas for cooking. New kitchens need tested pipework, a working ventilation interlock and a commercial gas certificate.

Installing or altering commercial gas pipework

New pipework is designed around the load it has to carry, the pressure available and the route through the building. It is installed to IGEM/UP/2, which covers materials, jointing, supports, ventilation of ducts and identification.

Common projects for Leeds businesses include:

• Extending a supply to new plant or a new tenant area
• Replacing corroded steel pipework
• Adding isolation valves so that sections can be shut down independently
• Laying buried polyethylene pipework between buildings

See our commercial gas installation and underground pipework pages for more detail.

Do you need permission to dig?

On your own land, no highway permission is needed, but you should always obtain utility records and scan the ground before excavating.

If a pipe route crosses a public road, footway or verge, the highway authority must be involved. Within the city boundary this is Leeds City Council. A street works permit or a section 50 licence is normally required before work begins, and reinstatement has to meet the council's specification.

Motorways and trunk roads such as the M1, M62 and M621 are managed by National Highways.

Who is responsible for the gas supply to your building?

The gas network in West Yorkshire is operated by Northern Gas Networks, which has its head office in Leeds. The network owns the service pipe up to the emergency control valve. The meter is usually owned by a meter asset manager appointed through your supplier.

Requests for a new connection, a larger supply or a meter upgrade go to the network or your supplier. Pipework beyond the meter belongs to the property owner or occupier, and the law requires it to be kept in a safe condition.

If you ever smell gas, call the National Gas Emergency Service on 0800 111 999.

When should pipework be decommissioned?

Empty floors, closed kitchens and disused boiler rooms often still contain live gas. This is a risk during strip-out and a nuisance for the next tenant. It is a regular issue in older mill and warehouse conversions, where pipework from earlier uses has been boxed in and forgotten.

Decommissioning involves purging the gas from the redundant section, cutting it back to a live valve or tee, capping it and updating the pipework records. It is sensible to do this before demolition, before a change of use, or when a building moves to electric heating.

Repairs and faults

We investigate pressure loss, failed tightness tests and suspected leaks. Once a fault is found and repaired, the section is retested and purged so that gas can be restored safely. We explain what we found in plain terms, so you can decide whether a wider survey of the system is worthwhile.

Our team offers emergency gas repairs for commercial premises and works seven days a week.

Not just the city centre

Gas Main Installation provides the full range of commercial gas services across all LS postcode districts, from LS1 in the centre to Morley, Pudsey, Horsforth, Garforth, Rothwell, Wetherby and Otley.

We are not limited to Leeds itself. Our engineers also work in Wakefield, Castleford, Bradford, Harrogate, Dewsbury and York, and across the wider WF, BD, HG and YO postcode areas. As a UK-wide service, we can support clients with property in several regions.