A gas tightness (soundness) test confirms that a commercial gas installation holds pressure correctly, with no leaks in the pipework or connections. ComGas carries out tightness testing on new, altered and existing commercial installations for businesses across Surrey and surrounding counties.
A gas tightness test — sometimes called a soundness test — checks that a gas installation holds pressure correctly over a set period, confirming there is no leakage from the pipework, fittings or connections being tested. It is a specific, standalone procedure with its own defined method, distinct from a full gas safety certification visit and from the physical installation of pipework itself.
ComGas carries out tightness testing on new pipework as part of a wider installation project, on existing pipework where a test is required for its own sake, and ahead of purging or appliance commissioning where a new or altered installation needs to be confirmed sound before it goes into service. Testing can be arranged as a standalone visit or combined with related pipework, purging or decommissioning work. Our guide explains when you need gas tightness testing and purging, and the order the work is done in.
ComGas Services UK Ltd
Commercial gas tightness testing from Farnham, Surrey.
We can carry out a tightness test as its own visit, or as part of a wider pipework, purging or installation project.
Tightness testing carried out on any new or altered gas pipework before it is put into service, as a standard part of a pipework project.
A standalone tightness test on an existing commercial installation, where a test is required in its own right rather than following new pipework work.
Confirming an installation is sound before it is purged and appliances are commissioned, as part of a co-ordinated sequence of works.
Testing across plant rooms and installations with multiple appliances or connection points, planned to cover the full system.
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A tightness test involves isolating the section of pipework being tested, applying and monitoring test pressure over a set period, and confirming whether the installation holds that pressure within the expected tolerance. Where a test does not pass, the location of any leak is investigated and explained before deciding on the appropriate remedial step.
Testing is carried out by Gas Safe registered engineers using calibrated test equipment, and the result — pass, or the fault identified and next steps — is confirmed clearly. Where the test forms part of a wider pipework or purging project, it is sequenced so the installation is not commissioned until it has been confirmed sound.
A tightness test is normally required following any new pipework installation or alteration, before an installation or appliance is commissioned or recommissioned, and can also be requested independently where confirmation of an existing installation's condition is needed. We can advise on whether a test is the right next step for your specific situation.
The requirement for testing depends on the specific installation and works involved. We confirm what is needed before arranging a visit rather than applying a standard assumption to every site.
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Common questions about what a tightness test involves and when it is needed.
Talk to the gas testing teamA tightness test confirms that the section of pipework being tested holds a set test pressure over a defined period, without any drop that would indicate a leak. It is a specific procedure with its own method, rather than a general visual inspection.
Testing is normally carried out following new pipework installation or any alteration to existing pipework, and before an installation or appliance is commissioned. It can also be requested as a standalone check on an existing installation where confirmation is needed independently of any other work.
Where a test identifies a leak, we investigate to locate it and explain the finding clearly. Any remedial work required is then separately discussed and agreed before the installation is retested and put back into service.
Yes. Testing is frequently carried out as part of a sequence alongside pipework installation and gas purging, so the whole process — pipework, test, purge, commissioning — is co-ordinated as one project rather than arranged separately.
No. A tightness test is a specific, standalone check of the pipework's soundness. Full commercial gas safety certification covers the wider installation and appliances and sits on its own dedicated page — we can advise on which is relevant to your situation.
Tell us about the installation, whether it follows recent pipework work, and any timescale or access considerations. We can advise on the right approach.
For an urgent enquiry, please call our office directly.
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