Commercial Gas Purging, Testing and Installation in Nottingham

Why Is Gas Pipework Purged?

Pipework that has just been installed is full of air. If gas were simply turned on, the first thing to reach the burner would be a mixture of gas and air. At the wrong ratio that mixture is flammable inside the pipe.

Purging removes the risk. The air is displaced in a controlled way and vented to a safe place outdoors, until a test at the vent point shows the pipe holds gas only. Appliances can then be lit safely.

The reverse applies when pipework is taken out of use. Gas is purged out before anyone cuts, alters or removes it.

Direct Purging or Nitrogen Purging: Which Is Used When?

It comes down to volume. On a small installation, gas can displace air directly, provided the flow is fast enough to stop the two from mixing along the pipe. IGEM/UP/1A sets the limits for this.

On larger pipework, nitrogen is used as a buffer. It pushes the air out first. Gas then pushes the nitrogen out. This is indirect purging, more often called nitrogen purging, and it follows IGEM/UP/1. We calculate the volume of your pipework before quoting, so you know which method applies and why.

Gas Purging and Testing Services in Nottingham

Tightness Testing Before Any Purge

There is no point filling leaking pipework with gas. A tightness test comes first. The section is pressurised, left to settle and then monitored for a set period. The permitted pressure drop depends on the pipework volume and the gauge used.

New pipework also has a strength test at a higher pressure. If anything fails, we find the leak, repair it and test again. You receive a certificate showing the pressures, times and results.

For landlords and managing agents in Nottingham, a current tightness test certificate is also a useful record at the start and end of a lease.

Lace Market Lofts, Hockley Kitchens and City Centre Refits

The Lace Market and Hockley are packed with Victorian warehouses that now hold restaurants, bars, offices and apartments. Units change hands often, and each new operator wants the gas installation to suit their own layout.

We decommission what is no longer needed, install and test the new pipework, fit the extraction interlock and commission the appliances. Many of these buildings are listed, so external pipe routes and flues may need consent from the council. See commercial catering.

Science, Health and Education Sites

Nottingham has a large health and science sector. The Queen's Medical Centre, City Hospital, the two universities, the bioscience incubators near the centre and the pharmaceutical campus at Beeston all run boiler houses, steam plant and laboratory gas.

Work on these estates is planned around clinical and research needs. Shutdowns are agreed in advance, temporary supplies are arranged where required, and testing and purging records are issued promptly for the estates file.

Laboratory gas outlets, fume cupboard supplies and emergency shut off systems are tested along with the main pipework.

You can read more about our full range of commercial gas services, including gas testing & gas purging and commercial gas installation, or see the other areas we cover, such as Derby and Leicester. Commercial Gas Certificate works nationwide.

Industrial Estates From Colwick to Blenheim

Manufacturing and distribution in Nottingham are spread around the edge of the city. Colwick, Lenton Lane, Blenheim Industrial Estate at Bulwell, Netherfield and the units close to junction 26 of the M1 all have process plant, warehouse heating and long pipe runs. See commercial heating systems.

Large mains on these sites are purged with nitrogen. Where production cannot stop, hot tapping lets us connect a new branch to a live main.

Can a Supply Be Decommissioned Without Closing the Building?

Usually, yes. Most buildings have sectional isolation valves, so one part of the system can be taken out of service while the rest stays live.

We identify exactly what the redundant section feeds, isolate it, purge it, cap it and label it. We then tightness test the live pipework that remains. If the building needs no gas at all, the meter and service are removed by the supplier and the network.

A record of the work is left with you. It shows what was isolated, where it was capped and the result of the test on the remaining pipework. Future contractors will thank you for it.

Caves, Trams and Street Works

Nottingham sits on soft sandstone, and there are hundreds of man made caves beneath the city centre. Anyone planning excavation for a buried gas supply should check what lies below first.

The tram network is another consideration. Work close to the tramway needs the agreement of the tram operator. Nottingham City Council is the highway authority within the city and issues street works permits. Nottinghamshire County Council covers Beeston, West Bridgford, Arnold and the rest of the county.

Cadent runs the gas distribution network and owns the pipework up to the emergency control valve.

Towns and Postcodes Around the City

We cover Nottingham and the wider NG postcode area, including Beeston, West Bridgford, Arnold, Carlton, Hucknall, Long Eaton, Eastwood, Mansfield and Newark.

We also travel to Derby, Ilkeston, Loughborough, Grantham and the rest of the UK.

What if There Is a Gas Leak?

Call the National Gas Emergency Service on 0800 111 999. Once the supply is safe, our emergency gas repairs team covers Nottingham at any hour. We repair the leak, test the pipework and purge it back into service. For planned inspections and certificates, see commercial gas certificates.