Gas purging removes air from a new installation before commissioning, or removes gas from pipework being taken out of service — carried out to the appropriate procedure by Gas Safe registered engineers. ComGas provides gas purging for commercial installations across Surrey and surrounding counties.
Gas purging is the process of safely introducing gas into new pipework to remove air before an appliance is commissioned, or safely removing gas from pipework that is being taken out of service. It is a distinct procedure from a tightness test, which checks the pipework holds pressure, and from the physical installation of pipework itself — though the three are commonly carried out in sequence on the same project.
ComGas carries out gas purging as part of new installation commissioning, following pipework alterations, and as part of decommissioning works where redundant pipework is being safely removed from service. Purging is carried out to the appropriate industry procedure by Gas Safe registered engineers, sequenced correctly with any related testing, pipework or decommissioning work.
ComGas Services UK Ltd
Commercial gas purging from Farnham, Surrey.
We can carry out purging as its own visit, or sequenced with related pipework, testing or decommissioning work.
Removing air from new pipework so appliances can be safely commissioned once tightness testing has confirmed the installation is sound.
Purging pipework that has been extended or altered, before the affected section is returned to service.
Safely removing gas from pipework that is being taken permanently out of service, ahead of disconnection and capping.
Purging carried out once a tightness test has confirmed the installation is sound, as one co-ordinated sequence of works.
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Purging is carried out to the appropriate industry procedure, using the correct rate of purge, appropriate venting arrangements and gas detection to confirm when the process is complete. For a new installation, this follows a successful tightness test and precedes appliance commissioning. For decommissioning, purging removes gas from the pipework before it is physically disconnected and capped.
Because purging involves the deliberate release or introduction of gas into a system, it is carried out only by Gas Safe registered engineers, with the area managed appropriately throughout and the completion of the process confirmed before any further step — commissioning, or physical disconnection — proceeds.
Purging is most commonly needed when new pipework is being commissioned for the first time, when altered pipework is being returned to service, or when redundant pipework is being decommissioned and taken permanently out of use. We can confirm whether purging applies to your specific project when we scope the work.
Whether purging is required, and how it should be sequenced, depends on the specific installation and works involved. We confirm this as part of scoping the project rather than assuming it applies by default.
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Common questions about what gas purging involves and when it applies.
Talk to the gas purging teamA tightness test confirms that pipework holds pressure correctly, with no leaks. Purging is the separate process of introducing gas into new pipework to remove air, or removing gas from pipework being decommissioned. On a new installation, purging normally follows a successful tightness test.
No. Purging is also carried out when redundant pipework is being safely decommissioned and taken out of service, and following alterations to existing pipework before it is returned to use.
Where the sequence allows, testing and purging can often be arranged as one combined visit, with purging following a passed tightness test. We confirm the appropriate sequence when scoping the work.
Purging involves the deliberate introduction or release of gas within a controlled procedure, including correct venting and gas detection to confirm completion. This requires the competence and registration of a Gas Safe registered engineer to be carried out safely.
Where pipework is being taken permanently out of service, it is normally purged of gas before it is physically disconnected and capped. See our Gas Decommissioning page for how the full process fits together.
Tell us about the installation, whether it follows pipework work or forms part of a decommissioning project, and any timescale considerations.
For an urgent enquiry, please call our office directly.
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Message the ComGas office on 01252 214120.
